a reverb is a reverb is a reverb
[ardour.git] / gtk2_ardour / canvas-waveview.c
index 5563fe5a783b158d9a3973901d0b560a686ab1e2..bf7dad04297eb8e788b39e5a30912b881be95132 100644 (file)
@@ -1,5 +1,5 @@
 /*
-     Copyright (C) 2000-2002 Paul Davis 
+     Copyright (C) 2000-2002 Paul Davis
 
      This program is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published by
 #include <cairo.h>
 #include <string.h>
 #include <limits.h>
+#include <unistd.h>
 
-#include <ardour/dB.h>
+#include "ardour/dB.h"
 
 #include "logmeter.h"
 #include "canvas-waveview.h"
 #include "rgb_macros.h"
 
+/* POSIX guarantees casting between void* and function pointers, ISO C doesn't
+ * We can work around warnings by going one step deeper in our casts
+ */
+#if defined(_POSIX_VERSION) || defined(COMPILER_MINGW)
+#define POSIX_FUNC_PTR_CAST(type, object) *((type*) &(object))
+#endif // _POSIX_VERSION
 
-extern void c_stacktrace();
+extern void c_stacktrace(void);
 
 enum {
         PROP_0,
@@ -110,10 +117,13 @@ static void gnome_canvas_waveview_set_data_src   (GnomeCanvasWaveView *,
 static void gnome_canvas_waveview_set_channel    (GnomeCanvasWaveView *,
                                                   guint32);
 
-static gint32 gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview,
+static guint32 gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview,
                                                   gulong               start_sample,
                                                   gulong               end_sample);
 
+
+static int _gradient_rendering = 0;
+
 static GnomeCanvasItemClass *parent_class;
 
 GType
@@ -163,106 +173,106 @@ gnome_canvas_waveview_class_init (GnomeCanvasWaveViewClass *class)
                  PROP_DATA_SRC,
                  g_param_spec_pointer ("data_src", NULL, NULL,
                                        (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_CHANNEL,
                  g_param_spec_uint ("channel", NULL, NULL,
                                     0, G_MAXUINT, 0,
                                     (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_LENGTH_FUNCTION,
                  g_param_spec_pointer ("length_function", NULL, NULL,
                                        (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_SOURCEFILE_LENGTH_FUNCTION,
                  g_param_spec_pointer ("sourcefile_length_function", NULL, NULL,
                                       (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_PEAK_FUNCTION,
                  g_param_spec_pointer ("peak_function", NULL, NULL,
                                        (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_GAIN_FUNCTION,
                  g_param_spec_pointer ("gain_function", NULL, NULL,
                                        (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_GAIN_SRC,
                  g_param_spec_pointer ("gain_src", NULL, NULL,
                                       (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-       
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_CACHE,
                  g_param_spec_pointer ("cache", NULL, NULL,
                                        (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_CACHE_UPDATER,
                  g_param_spec_boolean ("cache_updater", NULL, NULL,
                                       FALSE,
                                       (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_SAMPLES_PER_UNIT,
                  g_param_spec_double ("samples_per_unit", NULL, NULL,
                                       0.0, G_MAXDOUBLE, 0.0,
                                       (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_AMPLITUDE_ABOVE_AXIS,
                  g_param_spec_double ("amplitude_above_axis", NULL, NULL,
                                       0.0, G_MAXDOUBLE, 0.0,
                                       (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_X,
                  g_param_spec_double ("x", NULL, NULL,
                                       0.0, G_MAXDOUBLE, 0.0,
                                       (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_Y,
                  g_param_spec_double ("y", NULL, NULL,
                                       0.0, G_MAXDOUBLE, 0.0,
                                       (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_HEIGHT,
                  g_param_spec_double ("height", NULL, NULL,
                                       0.0, G_MAXDOUBLE, 0.0,
                                       (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_WAVE_COLOR,
                  g_param_spec_uint ("wave_color", NULL, NULL,
                                     0, G_MAXUINT, 0,
                                     (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_CLIP_COLOR,
                  g_param_spec_uint ("clip_color", NULL, NULL,
                                     0, G_MAXUINT, 0,
                                     (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_ZERO_COLOR,
@@ -283,7 +293,7 @@ gnome_canvas_waveview_class_init (GnomeCanvasWaveViewClass *class)
                  g_param_spec_boolean ("filled", NULL, NULL,
                                        FALSE,
                                        (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_RECTIFIED,
@@ -304,16 +314,16 @@ gnome_canvas_waveview_class_init (GnomeCanvasWaveViewClass *class)
                  g_param_spec_boolean ("logscaled", NULL, NULL,
                                        FALSE,
                                        (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         g_object_class_install_property
                 (gobject_class,
                  PROP_REGION_START,
                  g_param_spec_uint ("region_start", NULL, NULL,
                                     0, G_MAXUINT, 0,
                                     (G_PARAM_READABLE | G_PARAM_WRITABLE)));
-        
+
         object_class->destroy = gnome_canvas_waveview_destroy;
-        
+
         item_class->update = gnome_canvas_waveview_update;
         item_class->bounds = gnome_canvas_waveview_bounds;
         item_class->point = gnome_canvas_waveview_point;
@@ -321,8 +331,14 @@ gnome_canvas_waveview_class_init (GnomeCanvasWaveViewClass *class)
         item_class->draw = gnome_canvas_waveview_draw;
 }
 
+void
+gnome_canvas_waveview_set_gradient_waveforms (int yn)
+{
+       _gradient_rendering = yn;
+}
+
 GnomeCanvasWaveViewCache*
-gnome_canvas_waveview_cache_new ()
+gnome_canvas_waveview_cache_new (void)
 {
        GnomeCanvasWaveViewCache *c;
 
@@ -378,13 +394,9 @@ gnome_canvas_waveview_init (GnomeCanvasWaveView *waveview)
 static void
 gnome_canvas_waveview_destroy (GtkObject *object)
 {
-       GnomeCanvasWaveView *waveview;
-
        g_return_if_fail (object != NULL);
        g_return_if_fail (GNOME_IS_CANVAS_WAVEVIEW (object));
 
-       waveview = GNOME_CANVAS_WAVEVIEW (object);
-
        if (GTK_OBJECT_CLASS (parent_class)->destroy)
                (* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
 }
@@ -393,7 +405,7 @@ gnome_canvas_waveview_destroy (GtkObject *object)
 #undef CACHE_MEMMOVE_OPTIMIZATION
 
 /** @return cache index of start_sample within the cache */
-static gint32
+static guint32
 gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_sample, gulong end_sample)
 {
        gulong required_cache_entries;
@@ -418,12 +430,12 @@ gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_
 #if DEBUG_CACHE
        // printf("waveview->region_start == %lu\n",waveview->region_start);
        // c_stacktrace ();
-       printf ("\n\n=> 0x%x cache @ 0x%x range: %lu - %lu request: %lu - %lu (%lu frames)\n", 
+       printf ("\n\n=> 0x%x cache @ 0x%x range: %lu - %lu request: %lu - %lu (%lu frames)\n",
                waveview, cache,
                cache->start, cache->end,
                start_sample, end_sample, end_sample - start_sample);
 #endif
-               
+
        if (cache->start <= start_sample && cache->end >= end_sample) {
 #if DEBUG_CACHE
                // printf ("0x%x: cache hit for %lu-%lu (cache holds: %lu-%lu\n",
@@ -433,11 +445,11 @@ gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_
        }
 
        /* make sure the cache is at least twice as wide as the screen width, and put the start sample
-          in the middle, ensuring that we cover the end_sample. 
+          in the middle, ensuring that we cover the end_sample.
        */
 
        /* Note the assumption that we have a 1:1 units:pixel ratio for the canvas. Its everywhere ... */
-       
+
        half_width = (gulong) floor ((waveview->screen_width * waveview->samples_per_unit)/2.0 + 0.5);
 
        if (start_sample < half_width) {
@@ -462,7 +474,7 @@ gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_
        }
 
 #if DEBUG_CACHE
-       fprintf (stderr, "AVAILABLE FRAMES = %lu of %lu, start = %lu, sstart = %lu, cstart = %lu\n", 
+       fprintf (stderr, "AVAILABLE FRAMES = %lu of %lu, start = %lu, sstart = %lu, cstart = %lu\n",
                 rf3, waveview->sourcefile_length_function (waveview->data_src, waveview->samples_per_unit),
                 waveview->region_start, start_sample, new_cache_start);
 #endif
@@ -489,7 +501,7 @@ gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_
        ostart = new_cache_start;
 
 #ifdef CACHE_MEMMOVE_OPTIMIZATION
-       
+
        /* data is not entirely in the cache, so go fetch it, making sure to fill the cache */
 
        /* some of the required cache entries are in the cache, but in the wrong
@@ -497,24 +509,24 @@ gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_
        */
 
        if (cache->start < new_cache_start && new_cache_start < cache->end) {
-               
-               /* case one: the common area is at the end of the existing cache. move it 
+
+               /* case one: the common area is at the end of the existing cache. move it
                   to the beginning of the cache, and set up to refill whatever remains.
-                  
-                  
+
+
                           wv->cache_start                                        wv->cache_end
                           |-------------------------------------------------------| cache
                                                               |--------------------------------| requested
                                                               <------------------->
                                                                     "present"
-                                                           new_cache_start                      new_cache_end       
+                                                           new_cache_start                      new_cache_end
                */
-                               
+
 
                present_frames = cache->end - new_cache_start;
                present_entries = (gulong) floor (present_frames / waveview->samples_per_unit);
 
-#if DEBUG_CACHE                
+#if DEBUG_CACHE
                fprintf (stderr, "existing material at end of current cache, move to start of new cache\n"
                         "\tcopy from %lu to start\n", cache->data_size - present_entries);
 #endif
@@ -522,7 +534,7 @@ gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_
                memmove (&cache->data[0],
                         &cache->data[cache->data_size - present_entries],
                         present_entries * sizeof (GnomeCanvasWaveViewCacheEntry));
-               
+
 #if DEBUG_CACHE
                fprintf (stderr, "satisfied %lu of %lu frames, offset = %lu, will start at %lu (ptr = 0x%x)\n",
                         present_frames, required_frames, present_entries, new_cache_start + present_entries,
@@ -536,8 +548,8 @@ gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_
 
        } else if (new_cache_end > cache->start && new_cache_end < cache->end) {
 
-               /* case two: the common area lives at the beginning of the existing cache. 
-                  
+               /* case two: the common area lives at the beginning of the existing cache.
+
                                             wv->cache_start                                      wv->cache_end
                                             |-----------------------------------------------------|
                               |--------------------------------|
@@ -546,15 +558,15 @@ gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_
 
                              new_cache_start                      new_cache_end
                */
-               
+
                present_frames = new_cache_end - cache->start;
                present_entries = (gulong) floor (present_frames / waveview->samples_per_unit);
 
                memmove (&cache->data[cache->data_size - present_entries],
                         &cache->data[0],
                         present_entries * sizeof (GnomeCanvasWaveViewCacheEntry));
-               
-#if DEBUG_CACHE                
+
+#if DEBUG_CACHE
                fprintf (stderr, "existing material at start of current cache, move to start of end cache\n");
 #endif
 
@@ -568,7 +580,7 @@ gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_
                offset = 0;
                required_frames -= present_frames;
 
-               
+
        } else {
                copied = 0;
                offset = 0;
@@ -605,7 +617,7 @@ gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_
                waveview->peak_function (waveview->data_src, npeaks, new_cache_start, required_frames, cache->data + offset, waveview->channel,waveview->samples_per_unit);
 
                /* take into account any copied peaks */
-               
+
                npeaks += copied;
        } else {
                npeaks = copied;
@@ -634,27 +646,27 @@ gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_
                }
 
                free (gain);
-       
+
        }
 
        /* do optional log scaling.  this implementation is not particularly efficient */
-       
+
        if (waveview->logscaled) {
                guint32 n;
                GnomeCanvasWaveViewCacheEntry* buf = cache->data;
-               
+
                for (n = 0; n < cache->data_size; ++n) {
 
                        if (buf[n].max > 0.0f) {
-                               buf[n].max = alt_log_meter(coefficient_to_dB(buf[n].max));
+                               buf[n].max = alt_log_meter(fast_coefficient_to_dB(buf[n].max));
                        } else if (buf[n].max < 0.0f) {
-                               buf[n].max = -alt_log_meter(coefficient_to_dB(-buf[n].max));
+                               buf[n].max = -alt_log_meter(fast_coefficient_to_dB(-buf[n].max));
                        }
-                       
+
                        if (buf[n].min > 0.0f) {
-                               buf[n].min = alt_log_meter(coefficient_to_dB(buf[n].min));
+                               buf[n].min = alt_log_meter(fast_coefficient_to_dB(buf[n].min));
                        } else if (buf[n].min < 0.0f) {
-                               buf[n].min = -alt_log_meter(coefficient_to_dB(-buf[n].min));
+                               buf[n].min = -alt_log_meter(fast_coefficient_to_dB(-buf[n].min));
                        }
                }
        }
@@ -664,10 +676,10 @@ gnome_canvas_waveview_ensure_cache (GnomeCanvasWaveView *waveview, gulong start_
 
   out:
 #if DEBUG_CACHE
-       fprintf (stderr, "return cache index = %d\n", 
-                (gint32) floor ((((double) (start_sample - cache->start)) / waveview->samples_per_unit) + 0.5));
+       fprintf (stderr, "return cache index = %d\n",
+                (guint32) floor ((((double) (start_sample - cache->start)) / waveview->samples_per_unit) + 0.5));
 #endif
-       return (gint32) floor ((((double) (start_sample - cache->start)) / waveview->samples_per_unit) + 0.5);
+       return (guint32) floor ((((double) (start_sample - cache->start)) / waveview->samples_per_unit) + 0.5);
 
 }
 
@@ -680,7 +692,7 @@ gnome_canvas_waveview_set_data_src (GnomeCanvasWaveView *waveview, void *data_sr
                        waveview->reload_cache_in_render = TRUE;
                        return;
                }
-       
+
                waveview->cache->start  = 0;
                waveview->cache->end = 0;
        }
@@ -694,11 +706,11 @@ gnome_canvas_waveview_set_channel (GnomeCanvasWaveView *waveview, guint32 chan)
        if (waveview->channel == chan) {
                return;
        }
-       
+
        waveview->channel = chan;
 }
 
-static void 
+static void
 gnome_canvas_waveview_reset_bounds (GnomeCanvasItem *item)
 
 {
@@ -727,8 +739,8 @@ gnome_canvas_waveview_reset_bounds (GnomeCanvasItem *item)
        gnome_canvas_update_bbox (item, Ix1, Iy1, Ix2, Iy2);
 }
 
-/* 
- * CANVAS CALLBACKS 
+/*
+ * CANVAS CALLBACKS
  */
 
 static void
@@ -738,6 +750,8 @@ gnome_canvas_waveview_set_property (GObject      *object,
                                    GParamSpec   *pspec)
 
 {
+       (void) pspec;
+
        GnomeCanvasItem *item;
        GnomeCanvasWaveView *waveview;
        int redraw = FALSE;
@@ -749,6 +763,7 @@ gnome_canvas_waveview_set_property (GObject      *object,
        item = GNOME_CANVAS_ITEM (object);
        waveview = GNOME_CANVAS_WAVEVIEW (object);
 
+       void * ptr;
        switch (prop_id) {
        case PROP_DATA_SRC:
                gnome_canvas_waveview_set_data_src (waveview, g_value_get_pointer(value));
@@ -761,22 +776,27 @@ gnome_canvas_waveview_set_property (GObject      *object,
                break;
 
        case PROP_LENGTH_FUNCTION:
-               waveview->length_function = g_value_get_pointer(value);
+               ptr = g_value_get_pointer(value);
+               waveview->length_function = POSIX_FUNC_PTR_CAST(waveview_length_function_t, ptr);
                redraw = TRUE;
                break;
+
        case PROP_SOURCEFILE_LENGTH_FUNCTION:
-               waveview->sourcefile_length_function = g_value_get_pointer(value);
+               ptr = g_value_get_pointer(value);
+               waveview->sourcefile_length_function = POSIX_FUNC_PTR_CAST(waveview_sourcefile_length_function_t, ptr);
                redraw = TRUE;
                break;
 
        case PROP_PEAK_FUNCTION:
-               waveview->peak_function = g_value_get_pointer(value);
+               ptr = g_value_get_pointer(value);
+               waveview->peak_function = POSIX_FUNC_PTR_CAST(waveview_peak_function_t, ptr);
                redraw = TRUE;
                break;
 
        case PROP_GAIN_FUNCTION:
-               waveview->gain_curve_function = g_value_get_pointer(value);
-               redraw = TRUE;
+               ptr = g_value_get_pointer(value);
+               waveview->gain_curve_function = POSIX_FUNC_PTR_CAST(waveview_gain_curve_function_t, ptr);
+                        redraw = TRUE;
                break;
 
        case PROP_GAIN_SRC:
@@ -926,8 +946,8 @@ gnome_canvas_waveview_get_property (
                GValue       *value,
                GParamSpec   *pspec)
 {
-       
-   
+
+
        g_return_if_fail (object != NULL);
        g_return_if_fail (GNOME_IS_CANVAS_WAVEVIEW (object));
 
@@ -943,19 +963,19 @@ gnome_canvas_waveview_get_property (
                break;
 
        case PROP_LENGTH_FUNCTION:
-               g_value_set_pointer(value, waveview->length_function);
+               g_value_set_pointer(value, POSIX_FUNC_PTR_CAST(void*, waveview->length_function));
                break;
 
        case PROP_SOURCEFILE_LENGTH_FUNCTION:
-               g_value_set_pointer(value, waveview->sourcefile_length_function);
+               g_value_set_pointer(value, POSIX_FUNC_PTR_CAST(void*, waveview->sourcefile_length_function));
                break;
 
        case PROP_PEAK_FUNCTION:
-               g_value_set_pointer(value, waveview->peak_function);
+               g_value_set_pointer(value, POSIX_FUNC_PTR_CAST(void*, waveview->peak_function));
                break;
 
        case PROP_GAIN_FUNCTION:
-               g_value_set_pointer(value, waveview->gain_curve_function);
+               g_value_set_pointer(value, POSIX_FUNC_PTR_CAST(void*, waveview->gain_curve_function));
                break;
 
        case PROP_GAIN_SRC:
@@ -1080,17 +1100,17 @@ gnome_canvas_waveview_update (GnomeCanvasItem *item, double *affine, ArtSVP *cli
                      &waveview->fill_a);
 
 //     check_cache (waveview, "end of update");
-}                                 
+}
 
 static void
-gnome_canvas_waveview_render (GnomeCanvasItem *item,
-                           GnomeCanvasBuf *buf)
+gnome_canvas_waveview_gradient_render (GnomeCanvasItem *item,
+                                      GnomeCanvasBuf *buf)
 {
        GnomeCanvasWaveView *waveview;
        gulong s1, s2;
        int clip_length = 0;
        int pymin, pymax;
-       int cache_index;
+       guint cache_index;
        double half_height;
        int x;
        char rectify;
@@ -1183,7 +1203,7 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
 
        clip_length = MIN(5,(waveview->height/4));
 
-       /* 
+       /*
           Now draw each line, clipping it appropriately. The clipping
           is done by the macros PAINT_FOO().
        */
@@ -1203,6 +1223,9 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
                int next_clip_max = 0;
                int next_clip_min = 0;
 
+               int wave_middle = (int) rint ((item->y1 + origin) * item->canvas->pixels_per_unit);
+               int wave_top = (int) rint ((item->y1) * item->canvas->pixels_per_unit);
+
                if (s1 < waveview->samples_per_unit) {
                        /* we haven't got a prev vars to compare with, so outline the whole line here */
                        prev_pymax = (int) rint ((item->y1 + origin) * item->canvas->pixels_per_unit);
@@ -1234,43 +1257,43 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
                }
                if(last_pymax != last_pymin) {
                        /* take the index of one sample right of what we render */
-                       int index = cache_index + (end - begin);
+                       guint index = cache_index + (end - begin);
 
                        if (index >= waveview->cache->data_size) {
-                               
+
                                /* the data we want is off the end of the cache, which must mean its beyond
                                   the end of the region's source; hence the peak values are 0 */
                                last_pymax = (int) rint ((item->y1 + origin) * item->canvas->pixels_per_unit);
                                last_pymin = (int) rint ((item->y1 + origin) * item->canvas->pixels_per_unit);
-                               
+
                        } else {
-                               
+
                                last_pymax = (int) rint ((item->y1 + origin - MIN(waveview->cache->data[index].max, 1.0) * half_height) * item->canvas->pixels_per_unit);
                                last_pymin = (int) rint ((item->y1 + origin - MAX(waveview->cache->data[index].min, -1.0) * half_height) * item->canvas->pixels_per_unit);
-                               
+
                        }
-                               
+
                }
 
-               /* 
+               /*
                 * initialize NEXT* variables for the first run, duplicated in the loop for speed
                 */
                max = waveview->cache->data[cache_index].max;
                min = waveview->cache->data[cache_index].min;
-               
+
                if (max >= 1.0) {
                        max = 1.0;
                        next_clip_max = 1;
                }
-               
+
                if (min <= -1.0) {
                        min = -1.0;
                        next_clip_min = 1;
                }
-               
+
                max *= half_height;
                min *= half_height;
-               
+
                next_pymax = (int) rint ((item->y1 + origin - max) * item->canvas->pixels_per_unit);
                next_pymin = (int) rint ((item->y1 + origin - min) * item->canvas->pixels_per_unit);
 
@@ -1308,7 +1331,7 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
                                        max = 1.0;
                                        next_clip_max = 1;
                                }
-                               
+
                                if (min <= -1.0) {
                                        min = -1.0;
                                        next_clip_min = 1;
@@ -1316,11 +1339,11 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
 
                                max *= half_height;
                                min *= half_height;
-                               
+
                                next_pymax = (int) rint ((item->y1 + origin - max) * item->canvas->pixels_per_unit);
                                next_pymin = (int) rint ((item->y1 + origin - min) * item->canvas->pixels_per_unit);
                        }
-                       
+
                        /* render */
                        if (pymax == pymin) {
                                PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymin);
@@ -1335,10 +1358,10 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
                                        if(pymax == fill_max) {
                                                PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax);
                                                ++fill_max;
+                                       } else {
+                                               PAINT_VERTA_GR(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax, fill_max, wave_middle, wave_top);
                                        }
-                                       else {
-                                               PAINT_VERTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax, fill_max);
-                                       }
+
                                }
 
                                if((prev_pymin > pymin && next_pymin > pymin) ||
@@ -1352,12 +1375,12 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
                                                PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymin);
                                        }
                                        else {
-                                               PAINT_VERTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, fill_min, pymin);
+                                               PAINT_VERTA_GR(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, fill_min, pymin, wave_middle, wave_top);
                                        }
                                }
 
                                if(fill_max < fill_min) {
-                                       PAINT_VERTA(buf, waveview->fill_r, waveview->fill_g, waveview->fill_b, waveview->fill_a, x, fill_max, fill_min);
+                                       PAINT_VERTA_GR(buf, waveview->fill_r, waveview->fill_g, waveview->fill_b, waveview->fill_a, x, fill_max, fill_min, wave_middle, wave_top);
                                }
                                else if(fill_max == fill_min) {
                                        PAINT_DOTA(buf, waveview->fill_r, waveview->fill_g, waveview->fill_b, waveview->fill_a, x, fill_max);
@@ -1365,11 +1388,16 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
                        }
 
                        if (clip_max) {
-                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymax, pymax+clip_length);
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymax, pymax + clip_length);
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a >> 1, x + 1, pymax, pymax + (clip_length -1));
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a >> 1, x - 1, pymax, pymax + (clip_length - 1));
+
                        }
-                       
+
                        if (clip_min) {
-                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymin-clip_length, pymin);
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a , x, pymin - clip_length, pymin);
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a >> 1, x + 1, pymin - (clip_length - 1), pymin);
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a >> 1, x - 1, pymin - (clip_length - 1), pymin);
                        }
 
                        prev_pymax = pymax;
@@ -1385,6 +1413,9 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
                int next_clip_max = 0;
                int next_clip_min = 0;
 
+               int wave_middle = (int) rint ((item->y1 + waveview->height) * item->canvas->pixels_per_unit);
+               int wave_top = (int) rint ((item->y1) * item->canvas->pixels_per_unit);
+
                // for rectified, this stays constant throughout the loop
                pymin = (int) rint ((item->y1 + waveview->height) * item->canvas->pixels_per_unit);
 
@@ -1423,7 +1454,7 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
                if(last_pymax < 0) {
                        /* take the index of one sample right of what we render */
                        int index = cache_index + (end - begin);
-                       
+
                        max = MIN(waveview->cache->data[index].max, 1.0);
                        min = MAX(waveview->cache->data[index].min, -1.0);
 
@@ -1434,26 +1465,26 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
                        last_pymax = (int) rint ((item->y1 + waveview->height - max * waveview->height) * item->canvas->pixels_per_unit);
                }
 
-               /* 
+               /*
                 * initialize NEXT* variables for the first run, duplicated in the loop for speed
                 */
                max = waveview->cache->data[cache_index].max;
                min = waveview->cache->data[cache_index].min;
-               
+
                if (max >= 1.0) {
                        max = 1.0;
                        next_clip_max = 1;
                }
-               
+
                if (min <= -1.0) {
                        min = -1.0;
                        next_clip_min = 1;
                }
-               
+
                if (fabs (min) > fabs (max)) {
                        max = fabs (min);
-               } 
-               
+               }
+
                next_pymax = (int) rint ((item->y1 + waveview->height - max * waveview->height) * item->canvas->pixels_per_unit);
 
                /*
@@ -1476,24 +1507,24 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
 
                                max = waveview->cache->data[cache_index].max;
                                min = waveview->cache->data[cache_index].min;
-                               
+
                                if (max >= 1.0) {
                                        max = 1.0;
                                        next_clip_max = 1;
                                }
-                               
+
                                if (min <= -1.0) {
                                        min = -1.0;
                                        next_clip_min = 1;
                                }
-                               
+
                                if (fabs (min) > fabs (max)) {
                                        max = fabs (min);
-                               } 
-                               
+                               }
+
                                next_pymax = (int) rint ((item->y1 + waveview->height - max * waveview->height) * item->canvas->pixels_per_unit);
                        }
-                       
+
                        /* render */
                        if (pymax == pymin) {
                                PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymin);
@@ -1510,7 +1541,7 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
                                                ++fill_max;
                                        }
                                        else {
-                                               PAINT_VERTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax, fill_max);
+                                               PAINT_VERTA_GR(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax, fill_max, wave_middle, wave_top);
                                        }
                                }
 
@@ -1523,11 +1554,15 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
                        }
 
                        if (clip_max) {
-                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymax, pymax+clip_length);
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymax, pymax + clip_length);
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a >> 1, x + 1, pymax, pymax + (clip_length -1));
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a >> 1, x - 1, pymax, pymax + (clip_length - 1));
                        }
-                       
+
                        if (clip_min) {
-                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymin-clip_length, pymin);
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a , x, pymin - clip_length, pymin);
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a >> 1, x + 1, pymin - (clip_length - 1), pymin);
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a >> 1, x - 1, pymin - (clip_length - 1), pymin);
                        }
 
                        prev_pymax = pymax;
@@ -1537,185 +1572,724 @@ gnome_canvas_waveview_render (GnomeCanvasItem *item,
                cache_index = gnome_canvas_waveview_ensure_cache (waveview, s1, s2);
 
                for (x = begin; x < end; x++) {
-                       
+
                        double max, min;
                        int clip_max, clip_min;
-                       
+
                        clip_max = 0;
                        clip_min = 0;
-                       
+
                        max = waveview->cache->data[cache_index].max;
                        min = waveview->cache->data[cache_index].min;
-                       
+
                        if (max >= 1.0) {
                                max = 1.0;
                                clip_max = 1;
                        }
-                       
+
                        if (min <= -1.0) {
                                min = -1.0;
                                clip_min = 1;
                        }
-                       
+
                        if (rectify) {
-                               
+
                                if (fabs (min) > fabs (max)) {
                                        max = fabs (min);
-                               } 
-                               
+                               }
+
                                max = max * waveview->height;
-                               
+
                                pymax = (int) rint ((item->y1 + waveview->height - max) * item->canvas->pixels_per_unit);
                                pymin = (int) rint ((item->y1 + waveview->height) * item->canvas->pixels_per_unit);
-                               
+
                        } else {
-                               
+
                                max = max * half_height;
                                min = min * half_height;
-                               
+
                                pymax = (int) rint ((item->y1 + origin - max) * item->canvas->pixels_per_unit);
                                pymin = (int) rint ((item->y1 + origin - min) * item->canvas->pixels_per_unit);
                        }
-                       
+
                        /* OK, now fill the RGB buffer at x=i with a line between pymin and pymax,
                           or, if samples_per_unit == 1, then a dot at each location.
                        */
-                       
+
                        if (pymax == pymin) {
                                PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymin);
                        } else {
                                PAINT_VERTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax, pymin);
                        }
-                       
+
                        /* show clipped waveforms with small red lines */
-                       
+
                        if (clip_max) {
                                PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymax, pymax+clip_length);
                        }
-                       
+
                        if (clip_min) {
                                PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymin-clip_length, pymin);
                        }
 
                        /* presto, we're done */
-               
+
                        cache_index++;
                }
        }
 
-       if (!waveview->rectified && waveview->zero_line) {
+       if (!waveview->rectified && waveview->zero_line && waveview->height >= 100) {
                // Paint zeroline.
-               //PAINT_HORIZA(buf, waveview->zero_r, waveview->zero_g, waveview->zero_b, waveview->zero_a, begin, endi-1, origin );
-               
+
                unsigned char zero_r, zero_g, zero_b, zero_a;
-               UINT_TO_RGBA( waveview->zero_color, &zero_r, &zero_g, &zero_b, &zero_a );
+               UINT_TO_RGBA( waveview->zero_color, &zero_r, &zero_g, &zero_b, &zero_a);
                int zeroline_y = (int) rint ((item->y1 + origin) * item->canvas->pixels_per_unit);
-               PAINT_HORIZA(buf, zero_r, zero_g, zero_b, zero_a, zbegin, end, zeroline_y);
+               PAINT_HORIZA(buf, zero_r, zero_g, zero_b, zero_a, zbegin, zend, zeroline_y);
        }
 #undef origin
 
 }
 
 static void
-gnome_canvas_waveview_draw (GnomeCanvasItem *item,
-                           GdkDrawable *drawable,
-                           int x, int y,
-                           int width, int height)
+gnome_canvas_waveview_flat_render (GnomeCanvasItem *item,
+                                  GnomeCanvasBuf *buf)
 {
        GnomeCanvasWaveView *waveview;
-       cairo_t* cr;
        gulong s1, s2;
-       int cache_index;
-       gboolean rectify;
-       double origin;
-       double clip_length;
-       double xoff;
-       double yoff = 0.0;
-       double ulx;
-       double uly;
-       double lrx;
-       double lry;
+       int clip_length = 0;
+       int pymin, pymax;
+       guint cache_index;
+       double half_height;
+       int x;
+       char rectify;
 
        waveview = GNOME_CANVAS_WAVEVIEW (item);
 
-       /* compute intersection of Drawable area and waveview,
-          in canvas coordinate space
-       */
+//     check_cache (waveview, "start of render");
 
-       if (x > waveview->bbox_ulx) {
-               ulx = x;
-       } else {
-               ulx = waveview->bbox_ulx;
+       if (parent_class->render) {
+               (*parent_class->render) (item, buf);
        }
 
-       if (y > waveview->bbox_uly) {
-               uly = y;
-       } else {
-               uly = waveview->bbox_uly;
+       if (buf->is_bg) {
+               gnome_canvas_buf_ensure_buf (buf);
+               buf->is_bg = FALSE;
        }
 
-       if (x + width > waveview->bbox_lrx) {
-               lrx = waveview->bbox_lrx;
-       } else {
-               lrx = x + width;
-       }
+       /* a "unit" means a pixel */
 
-       if (y + height > waveview->bbox_lry) {
-               lry = waveview->bbox_lry;
-       } else {
-               lry = y + height;
+       /* begin: render start x (units) */
+       int const begin = MAX (waveview->bbox_ulx, buf->rect.x0);
+
+        /* zbegin: start x for zero line (units) */
+       int const zbegin = (begin == waveview->bbox_ulx) ? (begin + 1) : begin;
+
+       /* end: render end x (units) */
+       int const end = (waveview->bbox_lrx >= 0) ? MIN (waveview->bbox_lrx,buf->rect.x1) : buf->rect.x1;
+
+       /* zend: end x for zero-line (units) */
+       int const zend = (end == waveview->bbox_lrx) ? (end - 1) : end;
+
+       if (begin == end) {
+               return;
        }
 
-       /* figure out which samples we need for the resulting intersection */
+       /* s1: start sample
+          s2: end sample
+       */
 
-       s1 = floor ((ulx - waveview->bbox_ulx) * waveview->samples_per_unit) ;
+       s1 = floor ((begin - waveview->bbox_ulx) * waveview->samples_per_unit);
 
-       if (lrx == waveview->bbox_lrx) {
+       // fprintf (stderr, "0x%x begins at sample %f\n", waveview, waveview->bbox_ulx * waveview->samples_per_unit);
+
+       if (end == waveview->bbox_lrx) {
                /* This avoids minor rounding errors when we have the
                   entire region visible.
                */
                s2 = waveview->samples;
        } else {
-               s2 = s1 + floor ((lrx - ulx) * waveview->samples_per_unit);
+               s2 = s1 + floor ((end - begin) * waveview->samples_per_unit);
        }
 
-       /* translate back to buffer coordinate space */
+#if 0
+       printf ("0x%x r (%d..%d)(%d..%d) bbox (%d..%d)(%d..%d)"
+               " b/e %d..%d s= %lu..%lu @ %f\n",
+               waveview,
+               buf->rect.x0,
+               buf->rect.x1,
+               buf->rect.y0,
+               buf->rect.y1,
+               waveview->bbox_ulx,
+               waveview->bbox_lrx,
+               waveview->bbox_uly,
+               waveview->bbox_lry,
+               begin, end, s1, s2,
+               waveview->samples_per_unit);
+#endif
 
-       ulx -= x;
-       uly -= y;
-       lrx -= x;
-       lry -= y;
+       /* now ensure that the cache is full and properly
+          positioned.
+       */
+
+//     check_cache (waveview, "pre-ensure");
+
+       if (waveview->cache_updater && waveview->reload_cache_in_render) {
+               waveview->cache->start = 0;
+               waveview->cache->end = 0;
+               waveview->reload_cache_in_render = FALSE;
+       }
+
+//     check_cache (waveview, "post-ensure");
 
        /* don't rectify at single-sample zoom */
-       if(waveview->rectified && waveview->samples_per_unit > 1.0) {
+       if (waveview->rectified && waveview->samples_per_unit > 1) {
                rectify = TRUE;
-       } else {
+       }
+       else {
                rectify = FALSE;
        }
 
        clip_length = MIN(5,(waveview->height/4));
 
-       cr = gdk_cairo_create (drawable);
-       cairo_set_line_width (cr, 0.5);
-
-       origin = waveview->bbox_uly - y + waveview->half_height;
-
-       cairo_rectangle (cr, ulx, uly, lrx - ulx, lry - uly);
-       cairo_clip (cr);
+       /*
+          Now draw each line, clipping it appropriately. The clipping
+          is done by the macros PAINT_FOO().
+       */
 
-       if (waveview->cache_updater && waveview->reload_cache_in_render) {
-               waveview->cache->start = 0;
-               waveview->cache->end = 0;
-               waveview->reload_cache_in_render = FALSE;
-       }
+       half_height = waveview->half_height;
 
-       cache_index = gnome_canvas_waveview_ensure_cache (waveview, s1, s2);
+/* this makes it slightly easier to comprehend whats going on */
+#define origin half_height
 
-#if 0
-       printf ("%p r (%d,%d)(%d,%d)[%d x %d] bbox (%d,%d)(%d,%d)[%d x %d]"
+       if (waveview->filled && !rectify) {
+               int prev_pymin = 1;
+               int prev_pymax = 0;
+               int last_pymin = 1;
+               int last_pymax = 0;
+               int next_pymin, next_pymax;
+               double max, min;
+               int next_clip_max = 0;
+               int next_clip_min = 0;
+
+               if (s1 < waveview->samples_per_unit) {
+                       /* we haven't got a prev vars to compare with, so outline the whole line here */
+                       prev_pymax = (int) rint ((item->y1 + origin) * item->canvas->pixels_per_unit);
+                       prev_pymin = prev_pymax;
+               }
+               else {
+                       s1 -= waveview->samples_per_unit;
+               }
+
+               if(end == waveview->bbox_lrx) {
+                       /* we don't have the NEXT vars for the last sample */
+                       last_pymax = (int) rint ((item->y1 + origin) * item->canvas->pixels_per_unit);
+                       last_pymin = last_pymax;
+               }
+               else {
+                       s2 += waveview->samples_per_unit;
+               }
+
+               cache_index = gnome_canvas_waveview_ensure_cache (waveview, s1, s2);
+
+               /*
+                * Compute the variables outside the rendering rect
+                */
+               if(prev_pymax != prev_pymin) {
+
+                       prev_pymax = (int) rint ((item->y1 + origin - MIN(waveview->cache->data[cache_index].max, 1.0) * half_height) * item->canvas->pixels_per_unit);
+                       prev_pymin = (int) rint ((item->y1 + origin - MAX(waveview->cache->data[cache_index].min, -1.0) * half_height) * item->canvas->pixels_per_unit);
+                       ++cache_index;
+               }
+               if(last_pymax != last_pymin) {
+                       /* take the index of one sample right of what we render */
+                       guint index = cache_index + (end - begin);
+
+                       if (index >= waveview->cache->data_size) {
+
+                               /* the data we want is off the end of the cache, which must mean its beyond
+                                  the end of the region's source; hence the peak values are 0 */
+                               last_pymax = (int) rint ((item->y1 + origin) * item->canvas->pixels_per_unit);
+                               last_pymin = (int) rint ((item->y1 + origin) * item->canvas->pixels_per_unit);
+
+                       } else {
+
+                               last_pymax = (int) rint ((item->y1 + origin - MIN(waveview->cache->data[index].max, 1.0) * half_height) * item->canvas->pixels_per_unit);
+                               last_pymin = (int) rint ((item->y1 + origin - MAX(waveview->cache->data[index].min, -1.0) * half_height) * item->canvas->pixels_per_unit);
+
+                       }
+
+               }
+
+               /*
+                * initialize NEXT* variables for the first run, duplicated in the loop for speed
+                */
+               max = waveview->cache->data[cache_index].max;
+               min = waveview->cache->data[cache_index].min;
+
+               if (max >= 1.0) {
+                       max = 1.0;
+                       next_clip_max = 1;
+               }
+
+               if (min <= -1.0) {
+                       min = -1.0;
+                       next_clip_min = 1;
+               }
+
+               max *= half_height;
+               min *= half_height;
+
+               next_pymax = (int) rint ((item->y1 + origin - max) * item->canvas->pixels_per_unit);
+               next_pymin = (int) rint ((item->y1 + origin - min) * item->canvas->pixels_per_unit);
+
+               /*
+                * And now the loop
+                */
+               for(x = begin; x < end; ++x) {
+                       int clip_max = next_clip_max;
+                       int clip_min = next_clip_min;
+                       int fill_max, fill_min;
+
+                       pymax = next_pymax;
+                       pymin = next_pymin;
+
+                       /* compute next */
+                       if(x == end - 1) {
+                               /*next is now the last column, which is outside the rendering rect, and possibly outside the region*/
+                               next_pymax = last_pymax;
+                               next_pymin = last_pymin;
+                       }
+                       else {
+                               ++cache_index;
+
+                               if (cache_index < waveview->cache->data_size) {
+                                       max = waveview->cache->data[cache_index].max;
+                                       min = waveview->cache->data[cache_index].min;
+                               } else {
+                                       max = min = 0;
+                               }
+
+                               next_clip_max = 0;
+                               next_clip_min = 0;
+
+                               if (max >= 1.0) {
+                                       max = 1.0;
+                                       next_clip_max = 1;
+                               }
+
+                               if (min <= -1.0) {
+                                       min = -1.0;
+                                       next_clip_min = 1;
+                               }
+
+                               max *= half_height;
+                               min *= half_height;
+
+                               next_pymax = (int) rint ((item->y1 + origin - max) * item->canvas->pixels_per_unit);
+                               next_pymin = (int) rint ((item->y1 + origin - min) * item->canvas->pixels_per_unit);
+                       }
+
+                       /* render */
+                       if (pymax == pymin) {
+                               PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymin);
+                       } else {
+                               if((prev_pymax < pymax && next_pymax < pymax) ||
+                                  (prev_pymax == pymax && next_pymax == pymax)) {
+                                       fill_max = pymax + 1;
+                                       PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax);
+                               }
+                               else {
+                                       fill_max = MAX(prev_pymax, next_pymax);
+                                       if(pymax == fill_max) {
+                                               PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax);
+                                               ++fill_max;
+                                       }
+                                       else {
+                                               PAINT_VERTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax, fill_max);
+                                       }
+                               }
+
+                               if((prev_pymin > pymin && next_pymin > pymin) ||
+                                  (prev_pymin == pymin && next_pymin == pymin)) {
+                                       fill_min = pymin - 1;
+                                       PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymin-1);
+                               }
+                               else {
+                                       fill_min = MIN(prev_pymin, next_pymin);
+                                       if(pymin == fill_min) {
+                                               PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymin);
+                                       }
+                                       else {
+                                               PAINT_VERTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, fill_min, pymin);
+                                       }
+                               }
+
+                               if(fill_max < fill_min) {
+                                       PAINT_VERTA(buf, waveview->fill_r, waveview->fill_g, waveview->fill_b, waveview->fill_a, x, fill_max, fill_min);
+                               }
+                               else if(fill_max == fill_min) {
+                                       PAINT_DOTA(buf, waveview->fill_r, waveview->fill_g, waveview->fill_b, waveview->fill_a, x, fill_max);
+                               }
+                       }
+
+                       if (clip_max) {
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymax, pymax+clip_length);
+                       }
+
+                       if (clip_min) {
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymin-clip_length, pymin);
+                       }
+
+                       prev_pymax = pymax;
+                       prev_pymin = pymin;
+               }
+
+       } else if (waveview->filled && rectify) {
+
+               int prev_pymax = -1;
+               int last_pymax = -1;
+               int next_pymax;
+               double max, min;
+               int next_clip_max = 0;
+               int next_clip_min = 0;
+
+               // for rectified, this stays constant throughout the loop
+               pymin = (int) rint ((item->y1 + waveview->height) * item->canvas->pixels_per_unit);
+
+               if(s1 < waveview->samples_per_unit) {
+                       /* we haven't got a prev vars to compare with, so outline the whole line here */
+                       prev_pymax = pymin;
+               }
+               else {
+                       s1 -= waveview->samples_per_unit;
+               }
+
+               if(end == waveview->bbox_lrx) {
+                       /* we don't have the NEXT vars for the last sample */
+                       last_pymax = pymin;
+               }
+               else {
+                       s2 += waveview->samples_per_unit;
+               }
+
+               cache_index = gnome_canvas_waveview_ensure_cache (waveview, s1, s2);
+
+               /*
+                * Compute the variables outside the rendering rect
+                */
+               if(prev_pymax < 0) {
+                       max = MIN(waveview->cache->data[cache_index].max, 1.0);
+                       min = MAX(waveview->cache->data[cache_index].min, -1.0);
+
+                       if (fabs (min) > fabs (max)) {
+                               max = fabs (min);
+                       }
+
+                       prev_pymax = (int) rint ((item->y1 + waveview->height - max * waveview->height) * item->canvas->pixels_per_unit);
+                       ++cache_index;
+               }
+               if(last_pymax < 0) {
+                       /* take the index of one sample right of what we render */
+                       int index = cache_index + (end - begin);
+
+                       max = MIN(waveview->cache->data[index].max, 1.0);
+                       min = MAX(waveview->cache->data[index].min, -1.0);
+
+                       if (fabs (min) > fabs (max)) {
+                               max = fabs (min);
+                       }
+
+                       last_pymax = (int) rint ((item->y1 + waveview->height - max * waveview->height) * item->canvas->pixels_per_unit);
+               }
+
+               /*
+                * initialize NEXT* variables for the first run, duplicated in the loop for speed
+                */
+               max = waveview->cache->data[cache_index].max;
+               min = waveview->cache->data[cache_index].min;
+
+               if (max >= 1.0) {
+                       max = 1.0;
+                       next_clip_max = 1;
+               }
+
+               if (min <= -1.0) {
+                       min = -1.0;
+                       next_clip_min = 1;
+               }
+
+               if (fabs (min) > fabs (max)) {
+                       max = fabs (min);
+               }
+
+               next_pymax = (int) rint ((item->y1 + waveview->height - max * waveview->height) * item->canvas->pixels_per_unit);
+
+               /*
+                * And now the loop
+                */
+               for(x = begin; x < end; ++x) {
+                       int clip_max = next_clip_max;
+                       int clip_min = next_clip_min;
+                       int fill_max;
+
+                       pymax = next_pymax;
+
+                       /* compute next */
+                       if(x == end - 1) {
+                               /*next is now the last column, which is outside the rendering rect, and possibly outside the region*/
+                               next_pymax = last_pymax;
+                       }
+                       else {
+                               ++cache_index;
+
+                               max = waveview->cache->data[cache_index].max;
+                               min = waveview->cache->data[cache_index].min;
+
+                               if (max >= 1.0) {
+                                       max = 1.0;
+                                       next_clip_max = 1;
+                               }
+
+                               if (min <= -1.0) {
+                                       min = -1.0;
+                                       next_clip_min = 1;
+                               }
+
+                               if (fabs (min) > fabs (max)) {
+                                       max = fabs (min);
+                               }
+
+                               next_pymax = (int) rint ((item->y1 + waveview->height - max * waveview->height) * item->canvas->pixels_per_unit);
+                       }
+
+                       /* render */
+                       if (pymax == pymin) {
+                               PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymin);
+                       } else {
+                               if((prev_pymax < pymax && next_pymax < pymax) ||
+                                  (prev_pymax == pymax && next_pymax == pymax)) {
+                                       fill_max = pymax + 1;
+                                       PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax);
+                               }
+                               else {
+                                       fill_max = MAX(prev_pymax, next_pymax);
+                                       if(pymax == fill_max) {
+                                               PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax);
+                                               ++fill_max;
+                                       }
+                                       else {
+                                               PAINT_VERTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax, fill_max);
+                                       }
+                               }
+
+                               if(fill_max < pymin) {
+                                       PAINT_VERTA(buf, waveview->fill_r, waveview->fill_g, waveview->fill_b, waveview->fill_a, x, fill_max, pymin);
+                               }
+                               else if(fill_max == pymin) {
+                                       PAINT_DOTA(buf, waveview->fill_r, waveview->fill_g, waveview->fill_b, waveview->fill_a, x, pymin);
+                               }
+                       }
+
+                       if (clip_max) {
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymax, pymax+clip_length);
+                       }
+
+                       if (clip_min) {
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymin-clip_length, pymin);
+                       }
+
+                       prev_pymax = pymax;
+               }
+       }
+       else {
+               cache_index = gnome_canvas_waveview_ensure_cache (waveview, s1, s2);
+
+               for (x = begin; x < end; x++) {
+
+                       double max, min;
+                       int clip_max, clip_min;
+
+                       clip_max = 0;
+                       clip_min = 0;
+
+                       max = waveview->cache->data[cache_index].max;
+                       min = waveview->cache->data[cache_index].min;
+
+                       if (max >= 1.0) {
+                               max = 1.0;
+                               clip_max = 1;
+                       }
+
+                       if (min <= -1.0) {
+                               min = -1.0;
+                               clip_min = 1;
+                       }
+
+                       if (rectify) {
+
+                               if (fabs (min) > fabs (max)) {
+                                       max = fabs (min);
+                               }
+
+                               max = max * waveview->height;
+
+                               pymax = (int) rint ((item->y1 + waveview->height - max) * item->canvas->pixels_per_unit);
+                               pymin = (int) rint ((item->y1 + waveview->height) * item->canvas->pixels_per_unit);
+
+                       } else {
+
+                               max = max * half_height;
+                               min = min * half_height;
+
+                               pymax = (int) rint ((item->y1 + origin - max) * item->canvas->pixels_per_unit);
+                               pymin = (int) rint ((item->y1 + origin - min) * item->canvas->pixels_per_unit);
+                       }
+
+                       /* OK, now fill the RGB buffer at x=i with a line between pymin and pymax,
+                          or, if samples_per_unit == 1, then a dot at each location.
+                       */
+
+                       if (pymax == pymin) {
+                               PAINT_DOTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymin);
+                       } else {
+                               PAINT_VERTA(buf, waveview->wave_r, waveview->wave_g, waveview->wave_b, waveview->wave_a, x, pymax, pymin);
+                       }
+
+                       /* show clipped waveforms with small red lines */
+
+                       if (clip_max) {
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymax, pymax+clip_length);
+                       }
+
+                       if (clip_min) {
+                               PAINT_VERTA(buf, waveview->clip_r, waveview->clip_g, waveview->clip_b, waveview->clip_a, x, pymin-clip_length, pymin);
+                       }
+
+                       /* presto, we're done */
+
+                       cache_index++;
+               }
+       }
+
+       if (!waveview->rectified && waveview->zero_line && waveview->height >= 100) {
+               // Paint zeroline.
+
+               unsigned char zero_r, zero_g, zero_b, zero_a;
+               UINT_TO_RGBA( waveview->zero_color, &zero_r, &zero_g, &zero_b, &zero_a);
+               int zeroline_y = (int) rint ((item->y1 + origin) * item->canvas->pixels_per_unit);
+               PAINT_HORIZA(buf, zero_r, zero_g, zero_b, zero_a, zbegin, zend, zeroline_y);
+       }
+#undef origin
+}
+
+static void
+gnome_canvas_waveview_render (GnomeCanvasItem *item,
+                             GnomeCanvasBuf *buf)
+{
+       if (_gradient_rendering) {
+               gnome_canvas_waveview_gradient_render (item, buf);
+       } else {
+               gnome_canvas_waveview_flat_render (item, buf);
+       }
+}
+
+static void
+gnome_canvas_waveview_draw (GnomeCanvasItem *item,
+                           GdkDrawable *drawable,
+                           int x, int y,
+                           int width, int height)
+{
+       GnomeCanvasWaveView *waveview;
+       cairo_t* cr;
+       gulong s1, s2;
+       int cache_index;
+       gboolean rectify;
+       double origin;
+       double xoff;
+       double yoff = 0.0;
+       double ulx;
+       double uly;
+       double lrx;
+       double lry;
+
+       waveview = GNOME_CANVAS_WAVEVIEW (item);
+
+       /* compute intersection of Drawable area and waveview,
+          in canvas coordinate space
+       */
+
+       if (x > waveview->bbox_ulx) {
+               ulx = x;
+       } else {
+               ulx = waveview->bbox_ulx;
+       }
+
+       if (y > waveview->bbox_uly) {
+               uly = y;
+       } else {
+               uly = waveview->bbox_uly;
+       }
+
+       if (x + width > waveview->bbox_lrx) {
+               lrx = waveview->bbox_lrx;
+       } else {
+               lrx = x + width;
+       }
+
+       if (y + height > waveview->bbox_lry) {
+               lry = waveview->bbox_lry;
+       } else {
+               lry = y + height;
+       }
+
+       /* figure out which samples we need for the resulting intersection */
+
+       s1 = floor ((ulx - waveview->bbox_ulx) * waveview->samples_per_unit) ;
+
+       if (lrx == waveview->bbox_lrx) {
+               /* This avoids minor rounding errors when we have the
+                  entire region visible.
+               */
+               s2 = waveview->samples;
+       } else {
+               s2 = s1 + floor ((lrx - ulx) * waveview->samples_per_unit);
+       }
+
+       /* translate back to buffer coordinate space */
+
+       ulx -= x;
+       uly -= y;
+       lrx -= x;
+       lry -= y;
+
+       /* don't rectify at single-sample zoom */
+       if(waveview->rectified && waveview->samples_per_unit > 1.0) {
+               rectify = TRUE;
+       } else {
+               rectify = FALSE;
+       }
+
+       cr = gdk_cairo_create (drawable);
+       cairo_set_line_width (cr, 0.5);
+
+       origin = waveview->bbox_uly - y + waveview->half_height;
+
+       cairo_rectangle (cr, ulx, uly, lrx - ulx, lry - uly);
+       cairo_clip (cr);
+
+       if (waveview->cache_updater && waveview->reload_cache_in_render) {
+               waveview->cache->start = 0;
+               waveview->cache->end = 0;
+               waveview->reload_cache_in_render = FALSE;
+       }
+
+       cache_index = gnome_canvas_waveview_ensure_cache (waveview, s1, s2);
+
+#if 0
+       printf ("%p r (%d,%d)(%d,%d)[%d x %d] bbox (%d,%d)(%d,%d)[%d x %d]"
                " draw (%.1f,%.1f)(%.1f,%.1f)[%.1f x %.1f] s= %lu..%lu\n",
                waveview,
-               x, y, 
+               x, y,
                x + width,
                y + height,
                width,
@@ -1734,7 +2308,7 @@ gnome_canvas_waveview_draw (GnomeCanvasItem *item,
 #endif
 
        /* draw the top half */
-       
+
        for (xoff = ulx; xoff < lrx; xoff++) {
                double max, min;
 
@@ -1744,19 +2318,19 @@ gnome_canvas_waveview_draw (GnomeCanvasItem *item,
                if (min <= -1.0) {
                        min = -1.0;
                }
-               
+
                if (max >= 1.0) {
                        max = 1.0;
                }
-               
+
                if (rectify) {
                        if (fabs (min) > fabs (max)) {
                                max = fabs (min);
-                       } 
-               } 
-               
+                       }
+               }
+
                yoff = origin - (waveview->half_height * max) + 0.5;
-               
+
                if (xoff == ulx) {
                        /* first point */
                        cairo_move_to (cr, xoff+0.5, yoff);
@@ -1768,9 +2342,9 @@ gnome_canvas_waveview_draw (GnomeCanvasItem *item,
        }
 
        /* from the final top point, move out of the clip zone */
-       
+
        cairo_line_to (cr, xoff + 10, yoff);
-       
+
        /* now draw the bottom half */
 
        for (--xoff, --cache_index; xoff >= ulx; --xoff) {
@@ -1791,23 +2365,23 @@ gnome_canvas_waveview_draw (GnomeCanvasItem *item,
        /* from the final lower point, move out of the clip zone */
 
        cairo_line_to (cr, xoff - 10, yoff);
-       
+
        /* close path to fill */
 
        cairo_close_path (cr);
 
        /* fill and stroke */
 
-       cairo_set_source_rgba (cr, 
-                              (waveview->fill_r/255.0), 
-                              (waveview->fill_g/255.0), 
-                              (waveview->fill_b/255.0), 
+       cairo_set_source_rgba (cr,
+                              (waveview->fill_r/255.0),
+                              (waveview->fill_g/255.0),
+                              (waveview->fill_b/255.0),
                               (waveview->fill_a/255.0));
        cairo_fill_preserve (cr);
-       cairo_set_source_rgba (cr, 
-                              (waveview->wave_r/255.0), 
-                              (waveview->wave_g/255.0), 
-                              (waveview->wave_b/255.0), 
+       cairo_set_source_rgba (cr,
+                              (waveview->wave_r/255.0),
+                              (waveview->wave_g/255.0),
+                              (waveview->wave_b/255.0),
                               (waveview->wave_a/255.0));
        cairo_stroke (cr);
 
@@ -1824,13 +2398,13 @@ gnome_canvas_waveview_draw (GnomeCanvasItem *item,
                        cairo_line_to (cr, xoff, yoff1 + clip_length);
                        cairo_stroke (cr);
                }
-               
+
                if (clip_min) {
                        cairo_move_to (cr, xoff, yoff2);
                        cairo_line_to (cr, xoff, yoff2 - clip_length);
                        cairo_stroke (cr);
                }
-               
+
 #endif
 
 static void
@@ -1853,14 +2427,21 @@ gnome_canvas_waveview_bounds (GnomeCanvasItem *item, double *x1, double *y1, dou
        gnome_canvas_item_i2w (item, &x, &y);
        gnome_canvas_w2c_d (GNOME_CANVAS(item->canvas), x, y, &c, &d);
        printf ("item bounds now (%g,%g),(%g,%g)\n", a, b, c, d);
-#endif         
+#endif
 
 }
 
 static double
 gnome_canvas_waveview_point (GnomeCanvasItem *item, double x, double y, int cx, int cy, GnomeCanvasItem **actual_item)
 {
-       /* XXX for now, point is never inside the wave 
+       (void) item;
+       (void) x;
+       (void) y;
+       (void) cx;
+       (void) cy;
+       (void) actual_item;
+
+       /* XXX for now, point is never inside the wave
        GnomeCanvasWaveView *waveview;
        double x1, y1, x2, y2;
        double dx, dy;
@@ -1878,7 +2459,7 @@ gnome_canvas_waveview_point (GnomeCanvasItem *item, double x, double y, int cx,
        gnome_canvas_waveview_bounds (item, &x1, &y1, &x2, &y2);
 
        /* Is point inside rectangle */
-       
+
        if ((x >= x1) && (y >= y1) && (x <= x2) && (y <= y2)) {
                return 0.0;
        }