X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fcanvas%2Futils.cc;h=2c8905b331a0233c97fc12836a07ae2dd7ad23e3;hb=c8c6bca6587450ff64303dbc994a4cd28d6ce7aa;hp=b431042c3573344b068e49a206a3b24fb620264a;hpb=e6521bb0434d88802aa28e75235bc8c19ebb9262;p=ardour.git diff --git a/libs/canvas/utils.cc b/libs/canvas/utils.cc index b431042c35..2c8905b331 100644 --- a/libs/canvas/utils.cc +++ b/libs/canvas/utils.cc @@ -21,136 +21,119 @@ #include #include #include + #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 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 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 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)); }