gl/msaa: Implement basic solid color fill

Introduce the very basic functionality of an MSAA compositor
for OpenGL. For this first patch only solid fills are supported.

1 files changed, 100 insertions, 1 deletions

diff --git a/src/cairo-gl-msaa-compositor.c b/src/cairo-gl-msaa-compositor.c
index 8e2c2ed5c..ab5501db0 100644
--- a/src/cairo-gl-msaa-compositor.c
+++ b/src/cairo-gl-msaa-compositor.c
@@ -48,6 +48,52 @@
 #include "cairo-traps-private.h"
 
 static cairo_int_status_t
+_draw_trap (cairo_gl_context_t		*ctx,
+	    cairo_gl_composite_t	*setup,
+	    cairo_trapezoid_t		*trap)
+{
+    cairo_point_t quad[4];
+
+    quad[0].x = _cairo_edge_compute_intersection_x_for_y (&trap->left.p1,
+							  &trap->left.p2,
+							  trap->top);
+    quad[0].y = trap->top;
+
+    quad[1].x = _cairo_edge_compute_intersection_x_for_y (&trap->left.p1,
+						      &trap->left.p2,
+						      trap->bottom);
+    quad[1].y = trap->bottom;
+
+    quad[2].x = _cairo_edge_compute_intersection_x_for_y (&trap->right.p1,
+						      &trap->right.p2,
+						      trap->bottom);
+    quad[2].y = trap->bottom;
+
+    quad[3].x = _cairo_edge_compute_intersection_x_for_y (&trap->right.p1,
+						      &trap->right.p2,
+						      trap->top);
+    quad[3].y = trap->top;
+    return _cairo_gl_composite_emit_quad_as_tristrip (ctx, setup, quad);
+}
+
+static cairo_int_status_t
+_draw_traps (cairo_gl_context_t		*ctx,
+	     cairo_gl_composite_t	*setup,
+	     cairo_traps_t		*traps)
+{
+    int i;
+    cairo_int_status_t status = CAIRO_STATUS_SUCCESS;
+
+    for (i = 0; i < traps->num_traps; i++) {
+	cairo_trapezoid_t *trap = traps->traps + i;
+	if (unlikely ((status = _draw_trap (ctx, setup, trap))))
+	    return status;
+    }
+
+   return status;
+}
+
+static cairo_int_status_t
 _cairo_gl_msaa_compositor_paint (const cairo_compositor_t	*compositor,
 				 cairo_composite_rectangles_t	*composite)
 {
@@ -82,7 +128,60 @@ _cairo_gl_msaa_compositor_fill (const cairo_compositor_t	*compositor,
 				double				 tolerance,
 				cairo_antialias_t		 antialias)
 {
-    return CAIRO_INT_STATUS_UNSUPPORTED;
+    cairo_gl_composite_t setup;
+    cairo_gl_surface_t *dst = (cairo_gl_surface_t *) composite->surface;
+    cairo_gl_context_t *ctx = NULL;
+    cairo_int_status_t status;
+    cairo_traps_t traps;
+
+    if (antialias != CAIRO_ANTIALIAS_NONE)
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+
+    if (! _cairo_composite_rectangles_can_reduce_clip (composite,
+						       composite->clip))
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+
+    _cairo_traps_init (&traps);
+    status = _cairo_path_fixed_fill_to_traps (path, fill_rule, tolerance, &traps);
+    if (unlikely (status))
+	goto cleanup_traps;
+
+    status = _cairo_gl_composite_init (&setup,
+				       composite->op,
+				       dst,
+				       FALSE, /* assume_component_alpha */
+				       &composite->bounded);
+    if (unlikely (status))
+	goto cleanup_traps;
+
+    status = _cairo_gl_composite_set_source (&setup,
+					     &composite->source_pattern.base,
+					     composite->bounded.x,
+					     composite->bounded.y,
+					     composite->bounded.x,
+					     composite->bounded.y,
+					     composite->bounded.width,
+					     composite->bounded.height);
+    if (unlikely (status))
+	goto cleanup_setup;
+
+    status = _cairo_gl_composite_begin_tristrip (&setup, &ctx);
+    if (unlikely (status))
+	goto cleanup_setup;
+
+    status = _draw_traps (ctx, &setup, &traps);
+    if (unlikely (status))
+        goto cleanup_setup;
+
+    _cairo_gl_composite_flush (ctx);
+cleanup_setup:
+    _cairo_gl_composite_fini (&setup);
+    if (ctx)
+	status = _cairo_gl_context_release (ctx, status);
+cleanup_traps:
+    _cairo_traps_fini (&traps);
+
+    return status;
 }
 
 static void