isa/mutter
1
0
Fork 0
mirror of https://github.com/brl/mutter.git synced 2025-06-14 01:09:30 +00:00
Code Issues Packages Projects Releases Wiki Activity

cogl-sub-texture: Optimise taking a sub texture of a sub texture

Browse Source 
When creating a Cogl sub-texture, if the full texture is also a sub
texture it will now just offset the x and y and reference the full
texture instead. This avoids one level of indirection when rendering
the texture which reduces the chances of getting rounding errors in
the calculations.
This commit is contained in:
Neil Roberts
2010-02-12 10:08:51 +00:00
parent 395518fb34
commit 8119c184da
3 changed files with 42 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
cogl/cogl-sub-texture.c
View File

@ -235,34 +235,51 @@ _cogl_sub_texture_set_wrap_mode_parameter (CoglTexture *tex,
static void
_cogl_sub_texture_free (CoglSubTexture *sub_tex)
{
cogl_handle_unref (sub_tex->next_texture);
cogl_handle_unref (sub_tex->full_texture);
g_free (sub_tex);
}
CoglHandle
_cogl_sub_texture_new (CoglHandle full_texture,
_cogl_sub_texture_new (CoglHandle next_texture,
int sub_x, int sub_y,
int sub_width, int sub_height)
{
CoglHandle full_texture;
CoglSubTexture *sub_tex;
CoglTexture *tex;
unsigned int full_width, full_height;
unsigned int next_width, next_height;
full_width = cogl_texture_get_width (full_texture);
full_height = cogl_texture_get_height (full_texture);
next_width = cogl_texture_get_width (next_texture);
next_height = cogl_texture_get_height (next_texture);
/* The region must specify a non-zero subset of the full texture */
g_return_val_if_fail (sub_x >= 0 && sub_y >= 0, COGL_INVALID_HANDLE);
g_return_val_if_fail (sub_width > 0 && sub_height > 0, COGL_INVALID_HANDLE);
g_return_val_if_fail (sub_x + sub_width <= full_width, COGL_INVALID_HANDLE);
g_return_val_if_fail (sub_y + sub_height <= full_height, COGL_INVALID_HANDLE);
g_return_val_if_fail (sub_x + sub_width <= next_width, COGL_INVALID_HANDLE);
g_return_val_if_fail (sub_y + sub_height <= next_height, COGL_INVALID_HANDLE);
sub_tex = g_new (CoglSubTexture, 1);
tex = COGL_TEXTURE (sub_tex);
tex->vtable = &cogl_sub_texture_vtable;
/* If the next texture is also a sub texture we can avoid one level
of indirection by referencing the full texture of that texture
instead. */
if (cogl_is_sub_texture (next_texture))
{
CoglSubTexture *other_sub_tex =
_cogl_sub_texture_pointer_from_handle (next_texture);
full_texture = other_sub_tex->full_texture;
sub_x += other_sub_tex->sub_x;
sub_y += other_sub_tex->sub_y;
}
else
full_texture = next_texture;
sub_tex->next_texture = cogl_handle_ref (next_texture);
sub_tex->full_texture = cogl_handle_ref (full_texture);
sub_tex->sub_x = sub_x;