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cogl-primitives: Check for repeating after the coordinate transform

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In _cogl_multitexture_quad_single_primitive we use a wrap mode of
GL_CLAMP_TO_EDGE if the texture coordinates are all in the range [0,1]
or GL_REPEAT otherwise. This is to avoid pulling in pixels from either
side when using GL_LINEAR filter mode and rendering the entire
texture. Previously it was checking using the unconverted texture
coordinates. This is ok unless the texture backend is radically
transforming the texture coordinates, such as in the sub texture
backend where the coordinates may map to something completely
different. We now check whether the coordinates are in range after
converting them.
This commit is contained in:
Neil Roberts 2009-11-27 15:47:22 +00:00
parent 812d4d25bb
commit 5fcb29c916
1 changed files with 37 additions and 50 deletions
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87
clutter/cogl/cogl/cogl-primitives.c
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@ -249,6 +249,9 @@ _cogl_multitexture_quad_single_primitive (float x_1,
const float *in_tex_coords;
float *out_tex_coords;
float default_tex_coords[4] = {0.0, 0.0, 1.0, 1.0};
gboolean need_repeat = FALSE;
gint coord_num;
GLenum wrap_mode;
tex_handle = cogl_material_layer_get_texture (layer);
@ -257,27 +260,41 @@ _cogl_multitexture_quad_single_primitive (float x_1,
if (tex_handle == COGL_INVALID_HANDLE)
continue;
in_tex_coords = &user_tex_coords[i * 4];
/* If the user didn't supply texture coordinates for this layer
then use the default coords */
if (i >= user_tex_coords_len / 4)
in_tex_coords = default_tex_coords;
else
in_tex_coords = &user_tex_coords[i * 4];
out_tex_coords = &final_tex_coords[i * 4];
memcpy (out_tex_coords, in_tex_coords, sizeof (GLfloat) * 4);
/* Convert the texture coordinates to GL. We also work out
whether any of the texture coordinates are outside the range
[0.0,1.0]. We need to do this after calling
transform_coords_to_gl in case the texture backend is munging
the coordinates (such as in the sub texture backend). This
should be safe to call because we know that the texture only
has one slice. */
for (coord_num = 0; coord_num < 2; coord_num++)
{
float *s = out_tex_coords + coord_num * 2;
float *t = s + 1;
_cogl_texture_transform_coords_to_gl (tex_handle, s, t);
if (*s < 0.0f || *s > 1.0f || *t < 0.0f || *t > 1.0f)
need_repeat = TRUE;
}
/* If the texture has waste or we are using GL_TEXTURE_RECT we
* can't handle texture repeating so we check that the texture
* coords lie in the range [0,1].
*
* NB: We already know that the texture isn't sliced so we can assume
* that the default coords (0,0) and (1,1) would only reference a single
* GL texture.
* can't handle texture repeating so we can't use the layer if
* repeating is required.
*
* NB: We already know that no texture matrix is being used if the
* texture doesn't support hardware repeat.
*/
if (!_cogl_texture_can_hardware_repeat (tex_handle)
&& i < user_tex_coords_len / 4
&& (in_tex_coords[0] < 0 || in_tex_coords[0] > 1.0
|| in_tex_coords[1] < 0 || in_tex_coords[1] > 1.0
|| in_tex_coords[2] < 0 || in_tex_coords[2] > 1.0
|| in_tex_coords[3] < 0 || in_tex_coords[3] > 1.0))
if (!_cogl_texture_can_hardware_repeat (tex_handle) && need_repeat)
{
if (i == 0)
{
@ -315,45 +332,15 @@ _cogl_multitexture_quad_single_primitive (float x_1,
}
}
/*
* Setup the texture unit...
*/
/* NB: The user might not have supplied texture coordinates for all
* layers... */
if (i < (user_tex_coords_len / 4))
{
GLenum wrap_mode;
/* If the texture coords are all in the range [0,1] then we want to
clamp the coords to the edge otherwise it can pull in edge pixels
from the wrong side when scaled */
if (in_tex_coords[0] >= 0 && in_tex_coords[0] <= 1.0
&& in_tex_coords[1] >= 0 && in_tex_coords[1] <= 1.0
&& in_tex_coords[2] >= 0 && in_tex_coords[2] <= 1.0
&& in_tex_coords[3] >= 0 && in_tex_coords[3] <= 1.0)
wrap_mode = GL_CLAMP_TO_EDGE;
else
wrap_mode = GL_REPEAT;
memcpy (out_tex_coords, in_tex_coords, sizeof (GLfloat) * 4);
_cogl_texture_set_wrap_mode_parameter (tex_handle, wrap_mode);
}
/* If we're not repeating then we want to clamp the coords
to the edge otherwise it can pull in edge pixels from the
wrong side when scaled */
if (need_repeat)
wrap_mode = GL_REPEAT;
else
{
memcpy (out_tex_coords, default_tex_coords, sizeof (GLfloat) * 4);
wrap_mode = GL_CLAMP_TO_EDGE;
_cogl_texture_set_wrap_mode_parameter (tex_handle, GL_CLAMP_TO_EDGE);
}
_cogl_texture_transform_coords_to_gl (tex_handle,
&out_tex_coords[0],
&out_tex_coords[1]);
_cogl_texture_transform_coords_to_gl (tex_handle,
&out_tex_coords[2],
&out_tex_coords[3]);
_cogl_texture_set_wrap_mode_parameter (tex_handle, wrap_mode);
}
_cogl_journal_log_quad (x_1,