mutter/cogl/cogl-meta-texture.c

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/*
* Cogl
*
This re-licenses Cogl 1.18 under the MIT license Since the Cogl 1.18 branch is actively maintained in parallel with the master branch; this is a counter part to commit 1b83ef938fc16b which re-licensed the master branch to use the MIT license. This re-licensing is a follow up to the proposal that was sent to the Cogl mailing list: http://lists.freedesktop.org/archives/cogl/2013-December/001465.html Note: there was a copyright assignment policy in place for Clutter (and therefore Cogl which was part of Clutter at the time) until the 11th of June 2010 and so we only checked the details after that point (commit 0bbf50f905) For each file, authors were identified via this Git command: $ git blame -p -C -C -C20 -M -M10 0bbf50f905..HEAD We received blanket approvals for re-licensing all Red Hat and Collabora contributions which reduced how many people needed to be contacted individually: - http://lists.freedesktop.org/archives/cogl/2013-December/001470.html - http://lists.freedesktop.org/archives/cogl/2014-January/001536.html Individual approval requests were sent to all the other identified authors who all confirmed the re-license on the Cogl mailinglist: http://lists.freedesktop.org/archives/cogl/2014-January As well as updating the copyright header in all sources files, the COPYING file has been updated to reflect the license change and also document the other licenses used in Cogl such as the SGI Free Software License B, version 2.0 and the 3-clause BSD license. This patch was not simply cherry-picked from master; but the same methodology was used to check the source files.
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* A Low Level GPU Graphics and Utilities API
*
* Copyright (C) 2011 Intel Corporation.
*
This re-licenses Cogl 1.18 under the MIT license Since the Cogl 1.18 branch is actively maintained in parallel with the master branch; this is a counter part to commit 1b83ef938fc16b which re-licensed the master branch to use the MIT license. This re-licensing is a follow up to the proposal that was sent to the Cogl mailing list: http://lists.freedesktop.org/archives/cogl/2013-December/001465.html Note: there was a copyright assignment policy in place for Clutter (and therefore Cogl which was part of Clutter at the time) until the 11th of June 2010 and so we only checked the details after that point (commit 0bbf50f905) For each file, authors were identified via this Git command: $ git blame -p -C -C -C20 -M -M10 0bbf50f905..HEAD We received blanket approvals for re-licensing all Red Hat and Collabora contributions which reduced how many people needed to be contacted individually: - http://lists.freedesktop.org/archives/cogl/2013-December/001470.html - http://lists.freedesktop.org/archives/cogl/2014-January/001536.html Individual approval requests were sent to all the other identified authors who all confirmed the re-license on the Cogl mailinglist: http://lists.freedesktop.org/archives/cogl/2014-January As well as updating the copyright header in all sources files, the COPYING file has been updated to reflect the license change and also document the other licenses used in Cogl such as the SGI Free Software License B, version 2.0 and the 3-clause BSD license. This patch was not simply cherry-picked from master; but the same methodology was used to check the source files.
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* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
This re-licenses Cogl 1.18 under the MIT license Since the Cogl 1.18 branch is actively maintained in parallel with the master branch; this is a counter part to commit 1b83ef938fc16b which re-licensed the master branch to use the MIT license. This re-licensing is a follow up to the proposal that was sent to the Cogl mailing list: http://lists.freedesktop.org/archives/cogl/2013-December/001465.html Note: there was a copyright assignment policy in place for Clutter (and therefore Cogl which was part of Clutter at the time) until the 11th of June 2010 and so we only checked the details after that point (commit 0bbf50f905) For each file, authors were identified via this Git command: $ git blame -p -C -C -C20 -M -M10 0bbf50f905..HEAD We received blanket approvals for re-licensing all Red Hat and Collabora contributions which reduced how many people needed to be contacted individually: - http://lists.freedesktop.org/archives/cogl/2013-December/001470.html - http://lists.freedesktop.org/archives/cogl/2014-January/001536.html Individual approval requests were sent to all the other identified authors who all confirmed the re-license on the Cogl mailinglist: http://lists.freedesktop.org/archives/cogl/2014-January As well as updating the copyright header in all sources files, the COPYING file has been updated to reflect the license change and also document the other licenses used in Cogl such as the SGI Free Software License B, version 2.0 and the 3-clause BSD license. This patch was not simply cherry-picked from master; but the same methodology was used to check the source files.
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* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
This re-licenses Cogl 1.18 under the MIT license Since the Cogl 1.18 branch is actively maintained in parallel with the master branch; this is a counter part to commit 1b83ef938fc16b which re-licensed the master branch to use the MIT license. This re-licensing is a follow up to the proposal that was sent to the Cogl mailing list: http://lists.freedesktop.org/archives/cogl/2013-December/001465.html Note: there was a copyright assignment policy in place for Clutter (and therefore Cogl which was part of Clutter at the time) until the 11th of June 2010 and so we only checked the details after that point (commit 0bbf50f905) For each file, authors were identified via this Git command: $ git blame -p -C -C -C20 -M -M10 0bbf50f905..HEAD We received blanket approvals for re-licensing all Red Hat and Collabora contributions which reduced how many people needed to be contacted individually: - http://lists.freedesktop.org/archives/cogl/2013-December/001470.html - http://lists.freedesktop.org/archives/cogl/2014-January/001536.html Individual approval requests were sent to all the other identified authors who all confirmed the re-license on the Cogl mailinglist: http://lists.freedesktop.org/archives/cogl/2014-January As well as updating the copyright header in all sources files, the COPYING file has been updated to reflect the license change and also document the other licenses used in Cogl such as the SGI Free Software License B, version 2.0 and the 3-clause BSD license. This patch was not simply cherry-picked from master; but the same methodology was used to check the source files.
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*
* Authors:
* Robert Bragg <robert@linux.intel.com>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "cogl-texture.h"
#include "cogl-matrix.h"
#include "cogl-spans.h"
#include "cogl-meta-texture.h"
#include "cogl-texture-rectangle-private.h"
#include <string.h>
#include <math.h>
typedef struct _ForeachData
{
float meta_region_coords[4];
CoglPipelineWrapMode wrap_s;
CoglPipelineWrapMode wrap_t;
CoglMetaTextureCallback callback;
void *user_data;
int width;
int height;
CoglTexture *padded_textures[9];
const float *grid_slice_texture_coords;
float slice_offset_s;
float slice_offset_t;
float slice_range_s;
float slice_range_t;
} ForeachData;
static void
padded_grid_repeat_cb (CoglTexture *slice_texture,
const float *slice_texture_coords,
const float *meta_coords,
void *user_data)
{
ForeachData *data;
float mapped_coords[4];
/* Ignore padding slices for the current grid */
if (!slice_texture)
return;
data = user_data;
/* NB: the slice_texture_coords[] we get here will always be
* normalized.
*
* We now need to map the normalized slice_texture_coords[] we have
* here back to the real slice coordinates we saved in the previous
* stage...
*/
mapped_coords[0] =
slice_texture_coords[0] * data->slice_range_s + data->slice_offset_s;
mapped_coords[1] =
slice_texture_coords[1] * data->slice_range_t + data->slice_offset_t;
mapped_coords[2] =
slice_texture_coords[2] * data->slice_range_s + data->slice_offset_s;
mapped_coords[3] =
slice_texture_coords[3] * data->slice_range_t + data->slice_offset_t;
data->callback (slice_texture,
mapped_coords, meta_coords, data->user_data);
}
static int
setup_padded_spans (CoglSpan *spans,
float start,
float end,
float range,
int *real_index)
{
int span_index = 0;
if (start > 0)
{
spans[0].start = 0;
spans[0].size = start;
spans[0].waste = 0;
span_index++;
spans[1].start = spans[0].size;
}
else
spans[span_index].start = 0;
spans[span_index].size = end - start;
spans[span_index].waste = 0;
*real_index = span_index;
span_index++;
if (end < range)
{
spans[span_index].start =
spans[span_index - 1].start + spans[span_index - 1].size;
spans[span_index].size = range - end;
spans[span_index].waste = 0;
span_index++;
}
return span_index;
}
/* This handles each sub-texture within the range [0,1] of our
* original meta texture and repeats each one separately across the
* users requested virtual texture coordinates.
*
* A notable advantage of this approach is that we will batch
* together callbacks corresponding to the same underlying slice
* together.
*/
Add -Wmissing-declarations to maintainer flags and fix problems This option to GCC makes it give a warning whenever a global function is defined without a declaration. This should catch cases were we've defined a function but forgot to put it in a header. In that case it is either only used within one file so we should make it static or we should declare it in a header. The following changes where made to fix problems: • Some functions were made static • cogl-path.h (the one containing the 1.0 API) was split into two files, one defining the functions and one defining the enums so that cogl-path.c can include the enum and function declarations from the 2.0 API as well as the function declarations from the 1.0 API. • cogl2-clip-state has been removed. This only had one experimental function called cogl_clip_push_from_path but as this is unstable we might as well remove it favour of the equivalent cogl_framebuffer_* API. • The GLX, SDL and WGL winsys's now have a private header to define their get_vtable function instead of directly declaring in the C file where it is called. • All places that were calling COGL_OBJECT_DEFINE need to have the cogl_is_whatever function declared so these have been added either as a public function or in a private header. • Some files that were not including the header containing their function declarations have been fixed to do so. • Any unused error quark functions have been removed. If we later want them we should add them back one by one and add a declaration for them in a header. • _cogl_is_framebuffer has been renamed to cogl_is_framebuffer and made a public function with a declaration in cogl-framebuffer.h • Similarly for CoglOnscreen. • cogl_vdraw_indexed_attributes is called cogl_framebuffer_vdraw_indexed_attributes in the header. The definition has been changed to match the header. • cogl_index_buffer_allocate has been removed. This had no declaration and I'm not sure what it's supposed to do. • CoglJournal has been changed to use the internal CoglObject macro so that it won't define an exported cogl_is_journal symbol. • The _cogl_blah_pointer_from_handle functions have been removed. CoglHandle isn't used much anymore anyway and in the few places where it is used I think it's safe to just use the implicit cast from void* to the right type. • The test-utils.h header for the conformance tests explicitly disables the -Wmissing-declaration option using a pragma because all of the tests declare their main function without a header. Any mistakes relating to missing declarations aren't really important for the tests. • cogl_quaternion_init_from_quaternion and init_from_matrix have been given declarations in cogl-quaternion.h Reviewed-by: Robert Bragg <robert@linux.intel.com>
2012-03-06 13:21:28 -05:00
static void
create_grid_and_repeat_cb (CoglTexture *slice_texture,
const float *slice_texture_coords,
const float *meta_coords,
void *user_data)
{
ForeachData *data = user_data;
CoglSpan x_spans[3];
int n_x_spans;
int x_real_index;
CoglSpan y_spans[3];
int n_y_spans;
int y_real_index;
/* NB: This callback is called for each slice of the meta-texture
* in the range [0,1].
*
* We define a "padded grid" for each slice of the meta-texture in
* the range [0,1]. The x axis and y axis grid lines are defined
* using CoglSpans.
*
* The padded grid maps over the meta-texture coordinates in the
* range [0,1] but only contains one valid cell that corresponds to
* current slice being iterated and all the surrounding cells just
* provide padding.
*
* Once we've defined our padded grid we then repeat that across
* the user's original region, calling their callback whenever
* we see our current slice - ignoring padding.
*
* NB: we can assume meta_coords[] are normalized at this point
* since TextureRectangles aren't iterated with this code-path.
*
* NB: spans are always defined using non-normalized coordinates
*/
n_x_spans = setup_padded_spans (x_spans,
meta_coords[0] * data->width,
meta_coords[2] * data->width,
data->width,
&x_real_index);
n_y_spans = setup_padded_spans (y_spans,
meta_coords[1] * data->height,
meta_coords[3] * data->height,
data->height,
&y_real_index);
data->padded_textures[n_x_spans * y_real_index + x_real_index] =
slice_texture;
/* Our callback is going to be passed normalized slice texture
* coordinates, and we will need to map the range [0,1] to the real
* slice_texture_coords we have here... */
data->grid_slice_texture_coords = slice_texture_coords;
data->slice_range_s = fabs (data->grid_slice_texture_coords[2] -
data->grid_slice_texture_coords[0]);
data->slice_range_t = fabs (data->grid_slice_texture_coords[3] -
data->grid_slice_texture_coords[1]);
data->slice_offset_s = MIN (data->grid_slice_texture_coords[0],
data->grid_slice_texture_coords[2]);
data->slice_offset_t = MIN (data->grid_slice_texture_coords[1],
data->grid_slice_texture_coords[3]);
/* Now actually iterate the region the user originally requested
* using the current padded grid */
_cogl_texture_spans_foreach_in_region (x_spans,
n_x_spans,
y_spans,
n_y_spans,
data->padded_textures,
data->meta_region_coords,
data->width,
data->height,
data->wrap_s,
data->wrap_t,
padded_grid_repeat_cb,
data);
/* Clear the padded_textures ready for the next iteration */
data->padded_textures[n_x_spans * y_real_index + x_real_index] = NULL;
}
#define SWAP(A,B) do { float tmp = B; B = A; A = tmp; } while (0)
typedef struct _ClampData
{
float start;
float end;
CoglBool s_flipped;
CoglBool t_flipped;
CoglMetaTextureCallback callback;
void *user_data;
} ClampData;
static void
clamp_s_cb (CoglTexture *sub_texture,
const float *sub_texture_coords,
const float *meta_coords,
void *user_data)
{
ClampData *clamp_data = user_data;
float mapped_meta_coords[4] = {
clamp_data->start,
meta_coords[1],
clamp_data->end,
meta_coords[3]
};
if (clamp_data->s_flipped)
SWAP (mapped_meta_coords[0], mapped_meta_coords[2]);
/* NB: we never need to flip the t coords when dealing with
* s-axis clamping so no need to check if ->t_flipped */
clamp_data->callback (sub_texture,
sub_texture_coords, mapped_meta_coords,
clamp_data->user_data);
}
static void
clamp_t_cb (CoglTexture *sub_texture,
const float *sub_texture_coords,
const float *meta_coords,
void *user_data)
{
ClampData *clamp_data = user_data;
float mapped_meta_coords[4] = {
meta_coords[0],
clamp_data->start,
meta_coords[2],
clamp_data->end,
};
if (clamp_data->s_flipped)
SWAP (mapped_meta_coords[0], mapped_meta_coords[2]);
if (clamp_data->t_flipped)
SWAP (mapped_meta_coords[1], mapped_meta_coords[3]);
clamp_data->callback (sub_texture,
sub_texture_coords, mapped_meta_coords,
clamp_data->user_data);
}
static CoglBool
foreach_clamped_region (CoglMetaTexture *meta_texture,
float *tx_1,
float *ty_1,
float *tx_2,
float *ty_2,
CoglPipelineWrapMode wrap_s,
CoglPipelineWrapMode wrap_t,
CoglMetaTextureCallback callback,
void *user_data)
{
float width = cogl_texture_get_width (COGL_TEXTURE (meta_texture));
ClampData clamp_data;
/* Consider that *tx_1 may be > *tx_2 and to simplify things
* we just flip them around if that's the case and keep a note
* of the fact that they are flipped. */
if (*tx_1 > *tx_2)
{
SWAP (*tx_1, *tx_2);
clamp_data.s_flipped = TRUE;
}
else
clamp_data.s_flipped = FALSE;
/* The same goes for ty_1 and ty_2... */
if (*ty_1 > *ty_2)
{
SWAP (*ty_1, *ty_2);
clamp_data.t_flipped = TRUE;
}
else
clamp_data.t_flipped = FALSE;
clamp_data.callback = callback;
clamp_data.user_data = user_data;
if (wrap_s == COGL_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE)
{
float max_s_coord;
float half_texel_width;
/* Consider that rectangle textures have non-normalized
* coordinates... */
if (cogl_is_texture_rectangle (meta_texture))
max_s_coord = width;
else
max_s_coord = 1.0;
half_texel_width = max_s_coord / (width * 2);
/* Handle any left clamped region */
if (*tx_1 < 0)
{
clamp_data.start = *tx_1;
clamp_data.end = MIN (0, *tx_2);;
cogl_meta_texture_foreach_in_region (meta_texture,
half_texel_width, *ty_1,
half_texel_width, *ty_2,
COGL_PIPELINE_WRAP_MODE_REPEAT,
wrap_t,
clamp_s_cb,
&clamp_data);
/* Have we handled everything? */
if (*tx_2 <= 0)
return TRUE;
/* clamp tx_1 since we've handled everything with x < 0 */
*tx_1 = 0;
}
/* Handle any right clamped region - including the corners */
if (*tx_2 > max_s_coord)
{
clamp_data.start = MAX (max_s_coord, *tx_1);
clamp_data.end = *tx_2;
cogl_meta_texture_foreach_in_region (meta_texture,
max_s_coord - half_texel_width,
*ty_1,
max_s_coord - half_texel_width,
*ty_2,
COGL_PIPELINE_WRAP_MODE_REPEAT,
wrap_t,
clamp_s_cb,
&clamp_data);
/* Have we handled everything? */
if (*tx_1 >= max_s_coord)
return TRUE;
/* clamp tx_2 since we've handled everything with x >
* max_s_coord */
*tx_2 = max_s_coord;
}
}
if (wrap_t == COGL_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE)
{
float height = cogl_texture_get_height (COGL_TEXTURE (meta_texture));
float max_t_coord;
float half_texel_height;
/* Consider that rectangle textures have non-normalized
* coordinates... */
if (cogl_is_texture_rectangle (meta_texture))
max_t_coord = height;
else
max_t_coord = 1.0;
half_texel_height = max_t_coord / (height * 2);
/* Handle any top clamped region */
if (*ty_1 < 0)
{
clamp_data.start = *ty_1;
clamp_data.end = MIN (0, *ty_2);;
cogl_meta_texture_foreach_in_region (meta_texture,
*tx_1, half_texel_height,
*tx_2, half_texel_height,
wrap_s,
COGL_PIPELINE_WRAP_MODE_REPEAT,
clamp_t_cb,
&clamp_data);
/* Have we handled everything? */
if (*tx_2 <= 0)
return TRUE;
/* clamp ty_1 since we've handled everything with y < 0 */
*ty_1 = 0;
}
/* Handle any bottom clamped region */
if (*ty_2 > max_t_coord)
{
clamp_data.start = MAX (max_t_coord, *ty_1);;
clamp_data.end = *ty_2;
cogl_meta_texture_foreach_in_region (meta_texture,
*tx_1,
max_t_coord - half_texel_height,
*tx_2,
max_t_coord - half_texel_height,
wrap_s,
COGL_PIPELINE_WRAP_MODE_REPEAT,
clamp_t_cb,
&clamp_data);
/* Have we handled everything? */
if (*ty_1 >= max_t_coord)
return TRUE;
/* clamp ty_2 since we've handled everything with y >
* max_t_coord */
*ty_2 = max_t_coord;
}
}
if (clamp_data.s_flipped)
SWAP (*tx_1, *tx_2);
if (clamp_data.t_flipped)
SWAP (*ty_1, *ty_2);
return FALSE;
}
typedef struct _NormalizeData
{
CoglMetaTextureCallback callback;
void *user_data;
float s_normalize_factor;
float t_normalize_factor;
} NormalizeData;
static void
normalize_meta_coords_cb (CoglTexture *slice_texture,
const float *slice_coords,
const float *meta_coords,
void *user_data)
{
NormalizeData *data = user_data;
float normalized_meta_coords[4] = {
meta_coords[0] * data->s_normalize_factor,
meta_coords[1] * data->t_normalize_factor,
meta_coords[2] * data->s_normalize_factor,
meta_coords[3] * data->t_normalize_factor
};
data->callback (slice_texture,
slice_coords, normalized_meta_coords,
data->user_data);
}
typedef struct _UnNormalizeData
{
CoglMetaTextureCallback callback;
void *user_data;
float width;
float height;
} UnNormalizeData;
static void
un_normalize_slice_coords_cb (CoglTexture *slice_texture,
const float *slice_coords,
const float *meta_coords,
void *user_data)
{
UnNormalizeData *data = user_data;
float un_normalized_slice_coords[4] = {
slice_coords[0] * data->width,
slice_coords[1] * data->height,
slice_coords[2] * data->width,
slice_coords[3] * data->height
};
data->callback (slice_texture,
un_normalized_slice_coords, meta_coords,
data->user_data);
}
void
cogl_meta_texture_foreach_in_region (CoglMetaTexture *meta_texture,
float tx_1,
float ty_1,
float tx_2,
float ty_2,
CoglPipelineWrapMode wrap_s,
CoglPipelineWrapMode wrap_t,
CoglMetaTextureCallback callback,
void *user_data)
{
CoglTexture *texture = COGL_TEXTURE (meta_texture);
float width = cogl_texture_get_width (texture);
float height = cogl_texture_get_height (texture);
NormalizeData normalize_data;
if (wrap_s == COGL_PIPELINE_WRAP_MODE_AUTOMATIC)
wrap_s = COGL_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE;
if (wrap_t == COGL_PIPELINE_WRAP_MODE_AUTOMATIC)
wrap_t = COGL_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE;
if (wrap_s == COGL_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE ||
wrap_t == COGL_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE)
{
CoglBool finished = foreach_clamped_region (meta_texture,
&tx_1, &ty_1, &tx_2, &ty_2,
wrap_s, wrap_t,
callback,
user_data);
if (finished)
return;
/* Since clamping has been handled we now want to normalize our
* wrap modes we se can assume from this point on we don't
* need to consider CLAMP_TO_EDGE. (NB: The spans code will
* assert that CLAMP_TO_EDGE isn't requested) */
if (wrap_s == COGL_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE)
wrap_s = COGL_PIPELINE_WRAP_MODE_REPEAT;
if (wrap_t == COGL_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE)
wrap_t = COGL_PIPELINE_WRAP_MODE_REPEAT;
}
/* It makes things simpler to deal with non-normalized region
* coordinates beyond this point and only re-normalize just before
* calling the user's callback... */
if (!cogl_is_texture_rectangle (COGL_TEXTURE (meta_texture)))
{
normalize_data.callback = callback;
normalize_data.user_data = user_data;
normalize_data.s_normalize_factor = 1.0f / width;
normalize_data.t_normalize_factor = 1.0f / height;
callback = normalize_meta_coords_cb;
user_data = &normalize_data;
tx_1 *= width;
ty_1 *= height;
tx_2 *= width;
ty_2 *= height;
}
/* XXX: at some point this wont be routed through the CoglTexture
* vtable, instead there will be a separate CoglMetaTexture
* interface vtable. */
if (texture->vtable->foreach_sub_texture_in_region)
{
ForeachData data;
data.meta_region_coords[0] = tx_1;
data.meta_region_coords[1] = ty_1;
data.meta_region_coords[2] = tx_2;
data.meta_region_coords[3] = ty_2;
data.wrap_s = wrap_s;
data.wrap_t = wrap_t;
data.callback = callback;
data.user_data = user_data;
data.width = width;
data.height = height;
memset (data.padded_textures, 0, sizeof (data.padded_textures));
/*
* 1) We iterate all the slices of the meta-texture only within
* the range [0,1].
*
* 2) We define a "padded grid" for each slice of the
* meta-texture in the range [0,1].
*
* The padded grid maps over the meta-texture coordinates in
* the range [0,1] but only contains one valid cell that
* corresponds to current slice being iterated and all the
* surrounding cells just provide padding.
*
* 3) Once we've defined our padded grid we then repeat that
* across the user's original region, calling their callback
* whenever we see our current slice - ignoring padding.
*
* A notable benefit of this design is that repeating a texture
* made of multiple slices will result in us repeating each
* slice in-turn so the user gets repeat callbacks for the same
* texture batched together. For manual emulation of texture
* repeats done by drawing geometry this makes it more likely
* that we can batch geometry.
*/
texture->vtable->foreach_sub_texture_in_region (texture,
0, 0, 1, 1,
create_grid_and_repeat_cb,
&data);
}
else
{
CoglSpan x_span = { 0, width, 0 };
CoglSpan y_span = { 0, height, 0 };
float meta_region_coords[4] = { tx_1, ty_1, tx_2, ty_2 };
UnNormalizeData un_normalize_data;
/* If we are dealing with a CoglTextureRectangle then we need a shim
* callback that un_normalizes the slice coordinates we get from
* _cogl_texture_spans_foreach_in_region before passing them to
* the user's callback. */
if (cogl_is_texture_rectangle (meta_texture))
{
un_normalize_data.callback = callback;
un_normalize_data.user_data = user_data;
un_normalize_data.width = width;
un_normalize_data.height = height;
callback = un_normalize_slice_coords_cb;
user_data = &un_normalize_data;
}
_cogl_texture_spans_foreach_in_region (&x_span, 1,
&y_span, 1,
&texture,
meta_region_coords,
width,
height,
wrap_s,
wrap_t,
callback,
user_data);
}
}
#undef SWAP