From bc86db1057f6ceb9cecd72be085bab7198136f29 Mon Sep 17 00:00:00 2001
From: Neil Roberts <neil@linux.intel.com>
Date: Thu, 10 Feb 2011 18:22:27 +0000
Subject: [PATCH] cogl-texture-2d: Add an internal wrapper around
 glCopyTexSubImage2D

This adds a function called _cogl_texture_2d_copy_from_framebuffer
which is a simple wrapper around glCopyTexSubImage2D. It is currently
specific to the texture 2D backend.
---
 cogl/cogl-texture-2d-private.h | 22 +++++++++++++++++++++
 cogl/cogl-texture-2d.c         | 35 ++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/cogl/cogl-texture-2d-private.h b/cogl/cogl-texture-2d-private.h
index bd36e8ffa..e6dad37cb 100644
--- a/cogl/cogl-texture-2d-private.h
+++ b/cogl/cogl-texture-2d-private.h
@@ -87,4 +87,26 @@ _cogl_texture_2d_new_from_foreign (GLuint gl_handle,
 void
 _cogl_texture_2d_externally_modified (CoglHandle handle);
 
+/*
+ * _cogl_texture_2d_copy_from_framebuffer:
+ * @handle: A handle to a 2D texture
+ * @dst_x: X-position to store the image within the texture
+ * @dst_y: Y-position to store the image within the texture
+ * @src_x: X-position to within the framebuffer to read from
+ * @src_y: Y-position to within the framebuffer to read from
+ * @width: width of the rectangle to copy
+ * @height: height of the rectangle to copy
+ *
+ * This copies a portion of the current read framebuffer into the
+ * texture.
+ */
+void
+_cogl_texture_2d_copy_from_framebuffer (CoglHandle handle,
+                                        int dst_x,
+                                        int dst_y,
+                                        int src_x,
+                                        int src_y,
+                                        int width,
+                                        int height);
+
 #endif /* __COGL_TEXTURE_2D_H */
diff --git a/cogl/cogl-texture-2d.c b/cogl/cogl-texture-2d.c
index 80ec5c7bd..e47f5a554 100644
--- a/cogl/cogl-texture-2d.c
+++ b/cogl/cogl-texture-2d.c
@@ -38,6 +38,7 @@
 #include "cogl-handle.h"
 #include "cogl-journal-private.h"
 #include "cogl-pipeline-opengl-private.h"
+#include "cogl-framebuffer-private.h"
 
 #include <string.h>
 #include <math.h>
@@ -441,6 +442,40 @@ _cogl_texture_2d_externally_modified (CoglHandle handle)
   COGL_TEXTURE_2D (handle)->mipmaps_dirty = TRUE;
 }
 
+void
+_cogl_texture_2d_copy_from_framebuffer (CoglHandle handle,
+                                        int dst_x,
+                                        int dst_y,
+                                        int src_x,
+                                        int src_y,
+                                        int width,
+                                        int height)
+{
+  CoglTexture2D *tex_2d;
+
+  g_return_if_fail (_cogl_is_texture_2d (handle));
+
+  tex_2d = COGL_TEXTURE_2D (handle);
+
+  /* Make sure the current framebuffers are bound. We explicitly avoid
+     flushing the clip state so we can bind our own empty state */
+  _cogl_framebuffer_flush_state (_cogl_get_draw_buffer (),
+                                 _cogl_get_read_buffer (),
+                                 0);
+
+  _cogl_bind_gl_texture_transient (GL_TEXTURE_2D,
+                                   tex_2d->gl_texture,
+                                   tex_2d->is_foreign);
+
+  glCopyTexSubImage2D (GL_TEXTURE_2D,
+                       0, /* level */
+                       dst_x, dst_y,
+                       src_x, src_y,
+                       width, height);
+
+  tex_2d->mipmaps_dirty = TRUE;
+}
+
 static int
 _cogl_texture_2d_get_max_waste (CoglTexture *tex)
 {