[cairo] [PATCH 04/39] [OpenVG] Added linear gradient source.

[tardyp at gmail.com]

From: Øyvind Kolås <pippin at gimp.org>

---
 src/cairo-openvg-surface.c |   69 ++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 69 insertions(+), 0 deletions(-)

diff --git a/src/cairo-openvg-surface.c b/src/cairo-openvg-surface.c
index ecbd848..77cd5df 100644
--- a/src/cairo-openvg-surface.c
+++ b/src/cairo-openvg-surface.c
@@ -305,6 +305,67 @@ _cairo_openvg_cairo_matrix_to_openvg (const cairo_matrix_t *src,
     dst[8] = /* w2  */ 0;
 }
 
+static void
+_cairo_openvg_setup_linear_source (VGPaint paint,
+                                   cairo_linear_pattern_t *lpat)
+{
+  cairo_pattern_t *abspat = (cairo_pattern_t *) lpat;
+  cairo_matrix_t   mat;
+  VGfloat linear[4];
+  double x0, y0;
+  double x1, y1;
+
+
+  cairo_pattern_get_matrix (abspat, &mat);
+
+  if (cairo_matrix_invert (&mat) == CAIRO_STATUS_INVALID_MATRIX)
+    {
+      /* FIXME: pass on error */
+      return;
+    }
+  x0 = _cairo_fixed_to_double (lpat->p1.x);
+  y0 = _cairo_fixed_to_double (lpat->p1.y);
+  x1 = _cairo_fixed_to_double (lpat->p2.x);
+  y1 = _cairo_fixed_to_double (lpat->p2.y);
+
+  cairo_matrix_transform_point (&mat, &x0, &y0);
+  cairo_matrix_transform_point (&mat, &x1, &y1);
+
+  linear[0] = x0;
+  linear[1] = y0;
+  linear[2] = x1;
+  linear[3] = y1;
+
+  vgSetParameteri (paint, VG_PAINT_COLOR_RAMP_SPREAD_MODE, VG_COLOR_RAMP_SPREAD_PAD);
+  vgSetParameteri (paint, VG_PAINT_TYPE, VG_PAINT_TYPE_LINEAR_GRADIENT);
+  vgSetParameterfv (paint, VG_PAINT_LINEAR_GRADIENT, 4, linear);
+
+  {
+    const cairo_gradient_pattern_t *pattern = &lpat->base;
+    VGint numstops = pattern->n_stops;
+    VGfloat *stops;
+    int i;
+
+    stops = malloc (sizeof (VGfloat) * numstops * 5); 
+    if (stops == NULL)
+      {
+        return; /* FIXME: report error state */
+      }
+
+    for (i=0; i< numstops; i++)
+      {
+        stops[i*5 + 1] = pattern->stops[i].color.red;
+        stops[i*5 + 2] = pattern->stops[i].color.green;
+        stops[i*5 + 0] = pattern->stops[i].color.blue;
+        stops[i*5 + 3] = pattern->stops[i].color.alpha;
+        stops[i*5 + 4] = 1;
+      }
+
+    vgSetParameterfv (paint, VG_PAINT_COLOR_RAMP_STOPS, numstops * 5, stops);
+    free (stops);
+  }
+}
+
 static void setup_source (VGPaint paint,
                           cairo_pattern_t *source)
 {
@@ -318,6 +379,12 @@ static void setup_source (VGPaint paint,
                          solid->color.alpha};
       vgSetParameterfv (paint, VG_PAINT_COLOR, 4, color);
     }
+  else if (source->type == CAIRO_PATTERN_TYPE_LINEAR)
+    {
+      cairo_linear_pattern_t *lpat = (cairo_linear_pattern_t *)source;
+      _cairo_openvg_setup_linear_source (paint, lpat);
+      return;
+    }
   else
     {
       printf ("not handling source of type: %i\n", source->type);
@@ -411,6 +478,7 @@ _cairo_openvg_surface_fill (void *asurface,
   return CAIRO_STATUS_SUCCESS;
 }
 
+#if 0
 static cairo_int_status_t
 _cairo_openvg_surface_show_glyphs (void *asurface,
                                 cairo_operator_t op,
@@ -422,6 +490,7 @@ _cairo_openvg_surface_show_glyphs (void *asurface,
     printf ("show_glyphs\n");
     return CAIRO_STATUS_SUCCESS;
 }
+#endif
 
 static const struct _cairo_surface_backend
 cairo_openvg_surface_backend = {
-- 
1.6.0.4