#include <cmath>
#include <stdint.h>
#include <cairomm/context.h>
+
#include "canvas/utils.h"
-using std::max;
-using std::min;
+using namespace std;
+using namespace ArdourCanvas;
void
-ArdourCanvas::color_to_hsv (Color color, double& h, double& s, double& v)
+ArdourCanvas::set_source_rgba (Cairo::RefPtr<Cairo::Context> context, Color color)
{
- double r, g, b, a;
- double cmax;
- double cmin;
- double delta;
-
- color_to_rgba (color, r, g, b, a);
-
- if (r > g) {
- cmax = max (r, b);
- } else {
- cmax = max (g, b);
- }
-
- if (r < g) {
- cmin = min (r, b);
- } else {
- cmin = min (g, b);
- }
-
- v = cmax;
-
- delta = cmax - cmin;
-
- if (cmax == 0) {
- // r = g = b == 0 ... v is undefined, s = 0
- s = 0.0;
- h = -1.0;
- }
-
- if (delta != 0.0) {
- if (cmax == r) {
- h = fmod ((g - b)/delta, 6.0);
- } else if (cmax == g) {
- h = ((b - r)/delta) + 2;
- } else {
- h = ((r - g)/delta) + 4;
- }
-
- h *= 60.0;
- }
-
- if (delta == 0 || cmax == 0) {
- s = 0;
- } else {
- s = delta / cmax;
- }
-
+ context->set_source_rgba (
+ ((color >> 24) & 0xff) / 255.0,
+ ((color >> 16) & 0xff) / 255.0,
+ ((color >> 8) & 0xff) / 255.0,
+ ((color >> 0) & 0xff) / 255.0
+ );
}
-ArdourCanvas::Color
-ArdourCanvas::hsv_to_color (double h, double s, double v, double a)
+void
+ArdourCanvas::set_source_rgb_a (Cairo::RefPtr<Cairo::Context> context, Color color, float alpha)
{
- s = min (1.0, max (0.0, s));
- v = min (1.0, max (0.0, v));
-
- if (s == 0) {
- // achromatic (grey)
- return rgba_to_color (v, v, v, a);
- }
+ context->set_source_rgba (
+ ((color >> 24) & 0xff) / 255.0,
+ ((color >> 16) & 0xff) / 255.0,
+ ((color >> 8) & 0xff) / 255.0,
+ alpha
+ );
+}
- h = min (360.0, max (0.0, h));
-
- double c = v * s;
- double x = c * (1.0 - fabs(fmod(h / 60.0, 2) - 1.0));
- double m = v - c;
-
- if (h >= 0.0 && h < 60.0) {
- return rgba_to_color (c + m, x + m, m, a);
- } else if (h >= 60.0 && h < 120.0) {
- return rgba_to_color (x + m, c + m, m, a);
- } else if (h >= 120.0 && h < 180.0) {
- return rgba_to_color (m, c + m, x + m, a);
- } else if (h >= 180.0 && h < 240.0) {
- return rgba_to_color (m, x + m, c + m, a);
- } else if (h >= 240.0 && h < 300.0) {
- return rgba_to_color (x + m, m, c + m, a);
- } else if (h >= 300.0 && h < 360.0) {
- return rgba_to_color (c + m, m, x + m, a);
- }
- return rgba_to_color (m, m, m, a);
+void
+ArdourCanvas::set_source_rgba (cairo_t *cr, Color color)
+{
+ cairo_set_source_rgba ( cr,
+ ((color >> 24) & 0xff) / 255.0,
+ ((color >> 16) & 0xff) / 255.0,
+ ((color >> 8) & 0xff) / 255.0,
+ ((color >> 0) & 0xff) / 255.0
+ );
}
void
-ArdourCanvas::color_to_rgba (Color color, double& r, double& g, double& b, double& a)
+ArdourCanvas::set_source_rgb_a (cairo_t *cr, Color color, float alpha)
{
- r = ((color >> 24) & 0xff) / 255.0;
- g = ((color >> 16) & 0xff) / 255.0;
- b = ((color >> 8) & 0xff) / 255.0;
- a = ((color >> 0) & 0xff) / 255.0;
+ cairo_set_source_rgba ( cr,
+ ((color >> 24) & 0xff) / 255.0,
+ ((color >> 16) & 0xff) / 255.0,
+ ((color >> 8) & 0xff) / 255.0,
+ alpha
+ );
}
-ArdourCanvas::Color
-ArdourCanvas::rgba_to_color (double r, double g, double b, double a)
+ArdourCanvas::Distance
+ArdourCanvas::distance_to_segment_squared (Duple const & p, Duple const & p1, Duple const & p2, double& t, Duple& at)
{
- /* clamp to [0 .. 1] range */
+ static const double kMinSegmentLenSquared = 0.00000001; // adjust to suit. If you use float, you'll probably want something like 0.000001f
+ static const double kEpsilon = 1.0E-14; // adjust to suit. If you use floats, you'll probably want something like 1E-7f
+ double dx = p2.x - p1.x;
+ double dy = p2.y - p1.y;
+ double dp1x = p.x - p1.x;
+ double dp1y = p.y - p1.y;
+ const double segLenSquared = (dx * dx) + (dy * dy);
+
+ if (segLenSquared >= -kMinSegmentLenSquared && segLenSquared <= kMinSegmentLenSquared) {
+ // segment is a point.
+ at = p1;
+ t = 0.0;
+ return ((dp1x * dp1x) + (dp1y * dp1y));
+ }
- r = min (1.0, max (0.0, r));
- g = min (1.0, max (0.0, g));
- b = min (1.0, max (0.0, b));
- a = min (1.0, max (0.0, a));
- /* convert to [0..255] range */
+ // Project a line from p to the segment [p1,p2]. By considering the line
+ // extending the segment, parameterized as p1 + (t * (p2 - p1)),
+ // we find projection of point p onto the line.
+ // It falls where t = [(p - p1) . (p2 - p1)] / |p2 - p1|^2
- unsigned int rc, gc, bc, ac;
- rc = rint (r * 255.0);
- gc = rint (g * 255.0);
- bc = rint (b * 255.0);
- ac = rint (a * 255.0);
+ t = ((dp1x * dx) + (dp1y * dy)) / segLenSquared;
- /* build-an-integer */
+ if (t < kEpsilon) {
+ // intersects at or to the "left" of first segment vertex (p1.x, p1.y). If t is approximately 0.0, then
+ // intersection is at p1. If t is less than that, then there is no intersection (i.e. p is not within
+ // the 'bounds' of the segment)
+ if (t > -kEpsilon) {
+ // intersects at 1st segment vertex
+ t = 0.0;
+ }
+ // set our 'intersection' point to p1.
+ at = p1;
+ // Note: If you wanted the ACTUAL intersection point of where the projected lines would intersect if
+ // we were doing PointLineDistanceSquared, then qx would be (p1.x + (t * dx)) and qy would be (p1.y + (t * dy)).
+
+ } else if (t > (1.0 - kEpsilon)) {
+ // intersects at or to the "right" of second segment vertex (p2.x, p2.y). If t is approximately 1.0, then
+ // intersection is at p2. If t is greater than that, then there is no intersection (i.e. p is not within
+ // the 'bounds' of the segment)
+ if (t < (1.0 + kEpsilon)) {
+ // intersects at 2nd segment vertex
+ t = 1.0;
+ }
+ // set our 'intersection' point to p2.
+ at = p2;
+ // Note: If you wanted the ACTUAL intersection point of where the projected lines would intersect if
+ // we were doing PointLineDistanceSquared, then qx would be (p1.x + (t * dx)) and qy would be (p1.y + (t * dy)).
+ } else {
+ // The projection of the point to the point on the segment that is perpendicular succeeded and the point
+ // is 'within' the bounds of the segment. Set the intersection point as that projected point.
+ at = Duple (p1.x + (t * dx), p1.y + (t * dy));
+ }
- return (rc << 24) | (gc << 16) | (bc << 8) | ac;
-}
+ // return the squared distance from p to the intersection point. Note that we return the squared distance
+ // as an optimization because many times you just need to compare relative distances and the squared values
+ // works fine for that. If you want the ACTUAL distance, just take the square root of this value.
+ double dpqx = p.x - at.x;
+ double dpqy = p.y - at.y;
-void
-ArdourCanvas::set_source_rgba (Cairo::RefPtr<Cairo::Context> context, Color color)
-{
- context->set_source_rgba (
- ((color >> 24) & 0xff) / 255.0,
- ((color >> 16) & 0xff) / 255.0,
- ((color >> 8) & 0xff) / 255.0,
- ((color >> 0) & 0xff) / 255.0
- );
+ return ((dpqx * dpqx) + (dpqy * dpqy));
}
projects / ardour.git / blobdiff