From 5db362dd6792af20282e0e9a2805ee6f1b921e44 Mon Sep 17 00:00:00 2001
From: Benjamin Otte <otte@redhat.com>
Date: Fri, 28 May 2010 10:24:33 +0200
Subject: [PATCH] gl: Keep a copy of the current operand in the context

Note that they are currently only valid as long as the
cairo_gl_composite_t exists, but that will be changed soon.
---
 src/cairo-gl-composite.c | 20 ++++++++++++++++----
 src/cairo-gl-private.h   |  2 ++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/cairo-gl-composite.c b/src/cairo-gl-composite.c
index 760aabbc2..55154c3a8 100644
--- a/src/cairo-gl-composite.c
+++ b/src/cairo-gl-composite.c
@@ -606,11 +606,13 @@ _cairo_gl_texture_set_attributes (cairo_gl_context_t         *ctx,
 }
 
 static void
-_cairo_gl_operand_setup_texture (cairo_gl_context_t *ctx,
-                                 cairo_gl_operand_t *operand,
+_cairo_gl_context_setup_operand (cairo_gl_context_t *ctx,
                                  GLuint              tex_unit,
+                                 cairo_gl_operand_t *operand,
                                  unsigned int        vertex_offset)
 {
+    memcpy (&ctx->operands[tex_unit], operand, sizeof (cairo_gl_operand_t));
+
     switch (operand->type) {
     default:
     case CAIRO_GL_OPERAND_COUNT:
@@ -656,6 +658,13 @@ _cairo_gl_operand_setup_texture (cairo_gl_context_t *ctx,
     }
 }
 
+static void
+_cairo_gl_context_destroy_operand (cairo_gl_context_t *ctx,
+                                   GLuint              tex_unit)
+{
+  memset (&ctx->operands[tex_unit], 0, sizeof (cairo_gl_operand_t));
+}
+
 static void
 _cairo_gl_operand_setup_fixed (cairo_gl_operand_t *operand,
                                GLuint tex_unit)
@@ -995,8 +1004,8 @@ _cairo_gl_composite_begin (cairo_gl_composite_t *setup,
     glVertexPointer (2, GL_FLOAT, ctx->vertex_size, NULL);
     glEnableClientState (GL_VERTEX_ARRAY);
 
-    _cairo_gl_operand_setup_texture (ctx, &setup->src, 0, dst_size);
-    _cairo_gl_operand_setup_texture (ctx, &setup->mask, 1, dst_size + src_size);
+    _cairo_gl_context_setup_operand (ctx, 0, &setup->src, dst_size);
+    _cairo_gl_context_setup_operand (ctx, 1, &setup->mask, dst_size + src_size);
 
     _cairo_gl_set_src_operand (ctx, setup);
     if (setup->has_component_alpha)
@@ -1241,6 +1250,9 @@ _cairo_gl_composite_end (cairo_gl_context_t *ctx,
     glDisable (GL_TEXTURE_1D);
     glDisable (ctx->tex_target);
 
+    _cairo_gl_context_destroy_operand (ctx, 0);
+    _cairo_gl_context_destroy_operand (ctx, 1);
+
     ctx->pre_shader = NULL;
 
     ctx->vertex_size = 0;
diff --git a/src/cairo-gl-private.h b/src/cairo-gl-private.h
index 434b1b1ff..070f79ce8 100644
--- a/src/cairo-gl-private.h
+++ b/src/cairo-gl-private.h
@@ -179,6 +179,8 @@ typedef struct _cairo_gl_context {
     cairo_gl_shader_t *pre_shader; /* for component alpha */
     cairo_gl_shader_t *current_shader;
 
+    cairo_gl_operand_t operands[2];
+
     char *vb;
     unsigned int vb_offset;
     unsigned int vertex_size;