mutter/cogl/driver/gl/cogl-clip-stack-gl.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.
2014-02-21 20:28:54 -05:00
* A Low Level GPU Graphics and Utilities API
*
* Copyright (C) 2007,2008,2009,2010,2011,2012 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.
2014-02-21 20:28:54 -05:00
* 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:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* 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:
* Neil Roberts <neil@linux.intel.com>
* Robert Bragg <robert@linux.intel.com>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "cogl-context-private.h"
#include "cogl-util-gl-private.h"
#include "cogl-primitives-private.h"
#include "cogl-pipeline-opengl-private.h"
#include "cogl-clip-stack-gl-private.h"
Add _primitive_draw to replace _framebuffer_draw_primitive When splitting out the CoglPath api we saw that we would be left with inconsistent drawing apis if the drawing apis in core Cogl were lumped into the cogl_framebuffer_ api considering other Cogl sub-libraries or that others will want to create higher level drawing apis outside of Cogl but can't use the same namespace. So that we can aim for a more consistent style this adds a cogl_primitive_draw() api, comparable to cogl_path_fill() or cogl_pango_show_layout() that's intended to replace cogl_framebuffer_draw_primitive() Note: the attribute and rectangle drawing apis are still in the cogl_framebuffer_ namespace and this might potentially change but in these cases there is no single object representing the thing being drawn so it seems a more reasonable they they live in the framebuffer namespace for now. Note: the cogl_framebuffer_draw_primitive() api isn't removed by this patch so it can more conveniently be cherry picked to the 1.16 branch so we can mark it deprecated for a short while. Even though it's marked as experimental api we know that there are people using the api so we'd like to give them a chance to switch to the new api. Reviewed-by: Neil Roberts <neil@linux.intel.com> (cherry picked from commit 418912b93ff81a47f9b38114d05335ab76277c48) Conflicts: cogl-pango/cogl-pango-display-list.c cogl/Makefile.am cogl/cogl-framebuffer.c cogl/cogl-pipeline-layer-state.h cogl/cogl2-path.c cogl/driver/gl/cogl-clip-stack-gl.c
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#include "cogl-primitive-private.h"
#ifndef GL_CLIP_PLANE0
#define GL_CLIP_PLANE0 0x3000
#define GL_CLIP_PLANE1 0x3001
#define GL_CLIP_PLANE2 0x3002
#define GL_CLIP_PLANE3 0x3003
#define GL_CLIP_PLANE4 0x3004
#define GL_CLIP_PLANE5 0x3005
#endif
static void
project_vertex (const CoglMatrix *modelview_projection,
float *vertex)
{
int i;
cogl_matrix_transform_point (modelview_projection,
&vertex[0], &vertex[1],
&vertex[2], &vertex[3]);
/* Convert from homogenized coordinates */
for (i = 0; i < 4; i++)
vertex[i] /= vertex[3];
}
static void
set_clip_plane (CoglFramebuffer *framebuffer,
int plane_num,
const float *vertex_a,
const float *vertex_b)
{
CoglContext *ctx = framebuffer->context;
float planef[4];
double planed[4];
float angle;
CoglMatrixStack *modelview_stack =
_cogl_framebuffer_get_modelview_stack (framebuffer);
CoglMatrixStack *projection_stack =
_cogl_framebuffer_get_projection_stack (framebuffer);
CoglMatrix inverse_projection;
cogl_matrix_stack_get_inverse (projection_stack, &inverse_projection);
/* Calculate the angle between the axes and the line crossing the
two points */
angle = atan2f (vertex_b[1] - vertex_a[1],
vertex_b[0] - vertex_a[0]) * (180.0/G_PI);
cogl_matrix_stack_push (modelview_stack);
/* Load the inverse of the projection matrix so we can specify the plane
* in screen coordinates */
cogl_matrix_stack_set (modelview_stack, &inverse_projection);
/* Rotate about point a */
cogl_matrix_stack_translate (modelview_stack,
vertex_a[0], vertex_a[1], vertex_a[2]);
/* Rotate the plane by the calculated angle so that it will connect
the two points */
cogl_matrix_stack_rotate (modelview_stack, angle, 0.0f, 0.0f, 1.0f);
cogl_matrix_stack_translate (modelview_stack,
-vertex_a[0], -vertex_a[1], -vertex_a[2]);
/* Clip planes can only be used when a fixed function backend is in
use so we know we can directly push this matrix to the builtin
state */
_cogl_matrix_entry_flush_to_gl_builtins (ctx,
modelview_stack->last_entry,
COGL_MATRIX_MODELVIEW,
framebuffer,
FALSE /* don't disable flip */);
planef[0] = 0;
planef[1] = -1.0;
planef[2] = 0;
planef[3] = vertex_a[1];
switch (ctx->driver)
{
default:
g_assert_not_reached ();
break;
case COGL_DRIVER_GLES1:
GE( ctx, glClipPlanef (plane_num, planef) );
break;
case COGL_DRIVER_GL:
Add a GL 3 driver This adds a new CoglDriver for GL 3 called COGL_DRIVER_GL3. When requested, the GLX, EGL and SDL2 winsyss will set the necessary attributes to request a forward-compatible core profile 3.1 context. That means it will have no deprecated features. To simplify the explosion of checks for specific combinations of context->driver, many of these conditionals have now been replaced with private feature flags that are checked instead. The GL and GLES drivers now initialise these private feature flags depending on which driver is used. The fixed function backends now explicitly check whether the fixed function private feature is available which means the GL3 driver will fall back to always using the GLSL progend. Since Rob's latest patches the GLSL progend no longer uses any fixed function API anyway so it should just work. The driver is currently lower priority than COGL_DRIVER_GL so it will not be used unless it is specificly requested. We may want to change this priority at some point because apparently Mesa can make some memory savings if a core profile context is used. In GL 3, getting the combined extensions string with glGetString is deprecated so this patch changes it to use glGetStringi to build up an array of extensions instead. _cogl_context_get_gl_extensions now returns this array instead of trying to return a const string. The caller is expected to free the array. Some issues with this patch: • GL 3 does not support GL_ALPHA format textures. We should probably make this a feature flag or something. Cogl uses this to render text which currently just throws a GL error and breaks so it's pretty important to do something about this before considering the GL3 driver to be stable. • GL 3 doesn't support client side vertex buffers. This probably doesn't matter because CoglBuffer won't normally use malloc'd buffers if VBOs are available, but it might but worth making malloc'd buffers a private feature and forcing it not to use them. • GL 3 doesn't support the default vertex array object. This patch just makes it create and bind a single non-default vertex array object which gets used just like the normal default object. Ideally it would be good to use vertex array objects properly and attach them to a CoglPrimitive to cache the state. Reviewed-by: Robert Bragg <robert@linux.intel.com> (cherry picked from commit 66c9db993595b3a22e63f4c201ea468bc9b88cb6)
2012-09-26 15:32:36 -04:00
case COGL_DRIVER_GL3:
planed[0] = planef[0];
planed[1] = planef[1];
planed[2] = planef[2];
planed[3] = planef[3];
GE( ctx, glClipPlane (plane_num, planed) );
break;
}
cogl_matrix_stack_pop (modelview_stack);
}
static void
set_clip_planes (CoglFramebuffer *framebuffer,
CoglMatrixEntry *modelview_entry,
float x_1,
float y_1,
float x_2,
float y_2)
{
CoglMatrix modelview_matrix;
CoglMatrixStack *projection_stack =
_cogl_framebuffer_get_projection_stack (framebuffer);
CoglMatrix projection_matrix;
CoglMatrix modelview_projection;
float signed_area;
float vertex_tl[4] = { x_1, y_1, 0, 1.0 };
float vertex_tr[4] = { x_2, y_1, 0, 1.0 };
float vertex_bl[4] = { x_1, y_2, 0, 1.0 };
float vertex_br[4] = { x_2, y_2, 0, 1.0 };
cogl_matrix_stack_get (projection_stack, &projection_matrix);
cogl_matrix_entry_get (modelview_entry, &modelview_matrix);
cogl_matrix_multiply (&modelview_projection,
&projection_matrix,
&modelview_matrix);
project_vertex (&modelview_projection, vertex_tl);
project_vertex (&modelview_projection, vertex_tr);
project_vertex (&modelview_projection, vertex_bl);
project_vertex (&modelview_projection, vertex_br);
/* Calculate the signed area of the polygon formed by the four
vertices so that we can know its orientation */
signed_area = (vertex_tl[0] * (vertex_tr[1] - vertex_bl[1])
+ vertex_tr[0] * (vertex_br[1] - vertex_tl[1])
+ vertex_br[0] * (vertex_bl[1] - vertex_tr[1])
+ vertex_bl[0] * (vertex_tl[1] - vertex_br[1]));
/* Set the clip planes to form lines between all of the vertices
using the same orientation as we calculated */
if (signed_area > 0.0f)
{
/* counter-clockwise */
set_clip_plane (framebuffer, GL_CLIP_PLANE0, vertex_tl, vertex_bl);
set_clip_plane (framebuffer, GL_CLIP_PLANE1, vertex_bl, vertex_br);
set_clip_plane (framebuffer, GL_CLIP_PLANE2, vertex_br, vertex_tr);
set_clip_plane (framebuffer, GL_CLIP_PLANE3, vertex_tr, vertex_tl);
}
else
{
/* clockwise */
set_clip_plane (framebuffer, GL_CLIP_PLANE0, vertex_tl, vertex_tr);
set_clip_plane (framebuffer, GL_CLIP_PLANE1, vertex_tr, vertex_br);
set_clip_plane (framebuffer, GL_CLIP_PLANE2, vertex_br, vertex_bl);
set_clip_plane (framebuffer, GL_CLIP_PLANE3, vertex_bl, vertex_tl);
}
}
static void
add_stencil_clip_rectangle (CoglFramebuffer *framebuffer,
CoglMatrixEntry *modelview_entry,
float x_1,
float y_1,
float x_2,
float y_2,
CoglBool first)
{
CoglMatrixStack *projection_stack =
_cogl_framebuffer_get_projection_stack (framebuffer);
CoglContext *ctx = cogl_framebuffer_get_context (framebuffer);
/* NB: This can be called while flushing the journal so we need
* to be very conservative with what state we change.
*/
_cogl_context_set_current_projection_entry (ctx,
projection_stack->last_entry);
_cogl_context_set_current_modelview_entry (ctx, modelview_entry);
if (first)
{
GE( ctx, glEnable (GL_STENCIL_TEST) );
/* Initially disallow everything */
GE( ctx, glClearStencil (0) );
GE( ctx, glClear (GL_STENCIL_BUFFER_BIT) );
/* Punch out a hole to allow the rectangle */
GE( ctx, glStencilFunc (GL_NEVER, 0x1, 0x1) );
GE( ctx, glStencilOp (GL_REPLACE, GL_REPLACE, GL_REPLACE) );
_cogl_rectangle_immediate (framebuffer,
ctx->stencil_pipeline,
x_1, y_1, x_2, y_2);
}
else
{
/* Add one to every pixel of the stencil buffer in the
rectangle */
GE( ctx, glStencilFunc (GL_NEVER, 0x1, 0x3) );
GE( ctx, glStencilOp (GL_INCR, GL_INCR, GL_INCR) );
_cogl_rectangle_immediate (framebuffer,
ctx->stencil_pipeline,
x_1, y_1, x_2, y_2);
/* Subtract one from all pixels in the stencil buffer so that
only pixels where both the original stencil buffer and the
rectangle are set will be valid */
GE( ctx, glStencilOp (GL_DECR, GL_DECR, GL_DECR) );
_cogl_context_set_current_projection_entry (ctx, &ctx->identity_entry);
_cogl_context_set_current_modelview_entry (ctx, &ctx->identity_entry);
_cogl_rectangle_immediate (framebuffer,
ctx->stencil_pipeline,
-1.0, -1.0, 1.0, 1.0);
}
/* Restore the stencil mode */
GE( ctx, glStencilFunc (GL_EQUAL, 0x1, 0x1) );
GE( ctx, glStencilOp (GL_KEEP, GL_KEEP, GL_KEEP) );
}
typedef void (*SilhouettePaintCallback) (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
void *user_data);
static void
add_stencil_clip_silhouette (CoglFramebuffer *framebuffer,
SilhouettePaintCallback silhouette_callback,
CoglMatrixEntry *modelview_entry,
float bounds_x1,
float bounds_y1,
float bounds_x2,
float bounds_y2,
CoglBool merge,
CoglBool need_clear,
void *user_data)
{
CoglMatrixStack *projection_stack =
_cogl_framebuffer_get_projection_stack (framebuffer);
CoglContext *ctx = cogl_framebuffer_get_context (framebuffer);
/* NB: This can be called while flushing the journal so we need
* to be very conservative with what state we change.
*/
_cogl_context_set_current_projection_entry (ctx,
projection_stack->last_entry);
_cogl_context_set_current_modelview_entry (ctx, modelview_entry);
pipeline: improve real_blend_enable checks Since _cogl_pipeline_update_blend_enable() can sometimes show up quite high in profiles; instead of calling _cogl_pipeline_update_blend_enable() whenever we change pipeline state that may affect blending we now just set a dirty flag and when we flush a pipeline we check this dirty flag and lazily calculate whether blender really needs to be enabled if it's set. Since it turns out we were too optimistic in assuming most GL drivers would recognize blending with ADD(src,0) is equivalent to disabling GL_BLEND we now check this case ourselves so we can always explicitly disable GL_BLEND if we know we don't need blending. This introduces the idea of an 'unknown_color_alpha' boolean to the pipeline flush code which is set whenever we can't guarantee that the color attribute is opaque. For example this is set whenever a user specifies a color attribute with 4 components when drawing a primitive. This boolean needs to be cached along with every pipeline because pipeline::real_blend_enabled depends on this and so we need to also call _cogl_pipeline_update_blend_enable() if the status of this changes. Incidentally with this patch we now no longer ever use _cogl_pipeline_set_blend_enable() internally. For now the internal api hasn't been removed though since we might want to consider re-purposing it as a public api since it will now not conflict with our own internal state tracking and could provide a more convenient way to disable blending than setting a blend string. Reviewed-by: Neil Roberts <neil@linux.intel.com> (cherry picked from commit ab2ae18f3207514c91fa6fd9f2d3f2ed93a86497)
2013-05-16 10:19:30 -04:00
_cogl_pipeline_flush_gl_state (ctx, ctx->stencil_pipeline,
framebuffer, FALSE, FALSE);
GE( ctx, glEnable (GL_STENCIL_TEST) );
GE( ctx, glColorMask (FALSE, FALSE, FALSE, FALSE) );
GE( ctx, glDepthMask (FALSE) );
if (merge)
{
GE (ctx, glStencilMask (2));
GE (ctx, glStencilFunc (GL_LEQUAL, 0x2, 0x6));
}
else
{
/* If we're not using the stencil buffer for clipping then we
don't need to clear the whole stencil buffer, just the area
that will be drawn */
if (need_clear)
/* If this is being called from the clip stack code then it
will have set up a scissor for the minimum bounding box of
all of the clips. That box will likely mean that this
_cogl_clear won't need to clear the entire
buffer. _cogl_framebuffer_clear_without_flush4f is used instead
of cogl_clear because it won't try to flush the journal */
_cogl_framebuffer_clear_without_flush4f (framebuffer,
COGL_BUFFER_BIT_STENCIL,
0, 0, 0, 0);
else
{
/* Just clear the bounding box */
GE( ctx, glStencilMask (~(GLuint) 0) );
GE( ctx, glStencilOp (GL_ZERO, GL_ZERO, GL_ZERO) );
_cogl_rectangle_immediate (framebuffer,
ctx->stencil_pipeline,
bounds_x1, bounds_y1,
bounds_x2, bounds_y2);
}
GE (ctx, glStencilMask (1));
GE (ctx, glStencilFunc (GL_LEQUAL, 0x1, 0x3));
}
GE (ctx, glStencilOp (GL_INVERT, GL_INVERT, GL_INVERT));
silhouette_callback (framebuffer, ctx->stencil_pipeline, user_data);
if (merge)
{
/* Now we have the new stencil buffer in bit 1 and the old
stencil buffer in bit 0 so we need to intersect them */
GE (ctx, glStencilMask (3));
GE (ctx, glStencilFunc (GL_NEVER, 0x2, 0x3));
GE (ctx, glStencilOp (GL_DECR, GL_DECR, GL_DECR));
/* Decrement all of the bits twice so that only pixels where the
value is 3 will remain */
_cogl_context_set_current_projection_entry (ctx, &ctx->identity_entry);
_cogl_context_set_current_modelview_entry (ctx, &ctx->identity_entry);
_cogl_rectangle_immediate (framebuffer, ctx->stencil_pipeline,
-1.0, -1.0, 1.0, 1.0);
_cogl_rectangle_immediate (framebuffer, ctx->stencil_pipeline,
-1.0, -1.0, 1.0, 1.0);
}
GE (ctx, glStencilMask (~(GLuint) 0));
GE (ctx, glDepthMask (TRUE));
GE (ctx, glColorMask (TRUE, TRUE, TRUE, TRUE));
GE (ctx, glStencilFunc (GL_EQUAL, 0x1, 0x1));
GE (ctx, glStencilOp (GL_KEEP, GL_KEEP, GL_KEEP));
}
static void
paint_primitive_silhouette (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
void *user_data)
{
Add _primitive_draw to replace _framebuffer_draw_primitive When splitting out the CoglPath api we saw that we would be left with inconsistent drawing apis if the drawing apis in core Cogl were lumped into the cogl_framebuffer_ api considering other Cogl sub-libraries or that others will want to create higher level drawing apis outside of Cogl but can't use the same namespace. So that we can aim for a more consistent style this adds a cogl_primitive_draw() api, comparable to cogl_path_fill() or cogl_pango_show_layout() that's intended to replace cogl_framebuffer_draw_primitive() Note: the attribute and rectangle drawing apis are still in the cogl_framebuffer_ namespace and this might potentially change but in these cases there is no single object representing the thing being drawn so it seems a more reasonable they they live in the framebuffer namespace for now. Note: the cogl_framebuffer_draw_primitive() api isn't removed by this patch so it can more conveniently be cherry picked to the 1.16 branch so we can mark it deprecated for a short while. Even though it's marked as experimental api we know that there are people using the api so we'd like to give them a chance to switch to the new api. Reviewed-by: Neil Roberts <neil@linux.intel.com> (cherry picked from commit 418912b93ff81a47f9b38114d05335ab76277c48) Conflicts: cogl-pango/cogl-pango-display-list.c cogl/Makefile.am cogl/cogl-framebuffer.c cogl/cogl-pipeline-layer-state.h cogl/cogl2-path.c cogl/driver/gl/cogl-clip-stack-gl.c
2013-07-09 18:47:29 -04:00
_cogl_primitive_draw (user_data,
framebuffer,
pipeline,
COGL_DRAW_SKIP_JOURNAL_FLUSH |
COGL_DRAW_SKIP_PIPELINE_VALIDATION |
COGL_DRAW_SKIP_FRAMEBUFFER_FLUSH |
COGL_DRAW_SKIP_LEGACY_STATE);
}
static void
add_stencil_clip_primitive (CoglFramebuffer *framebuffer,
CoglMatrixEntry *modelview_entry,
CoglPrimitive *primitive,
float bounds_x1,
float bounds_y1,
float bounds_x2,
float bounds_y2,
CoglBool merge,
CoglBool need_clear)
{
add_stencil_clip_silhouette (framebuffer,
paint_primitive_silhouette,
modelview_entry,
bounds_x1,
bounds_y1,
bounds_x2,
bounds_y2,
merge,
need_clear,
primitive);
}
static void
enable_clip_planes (CoglContext *ctx)
{
GE( ctx, glEnable (GL_CLIP_PLANE0) );
GE( ctx, glEnable (GL_CLIP_PLANE1) );
GE( ctx, glEnable (GL_CLIP_PLANE2) );
GE( ctx, glEnable (GL_CLIP_PLANE3) );
}
static void
disable_clip_planes (CoglContext *ctx)
{
GE( ctx, glDisable (GL_CLIP_PLANE3) );
GE( ctx, glDisable (GL_CLIP_PLANE2) );
GE( ctx, glDisable (GL_CLIP_PLANE1) );
GE( ctx, glDisable (GL_CLIP_PLANE0) );
}
void
_cogl_clip_stack_gl_flush (CoglClipStack *stack,
CoglFramebuffer *framebuffer)
{
CoglContext *ctx = framebuffer->context;
int has_clip_planes;
CoglBool using_clip_planes = FALSE;
CoglBool using_stencil_buffer = FALSE;
int scissor_x0;
int scissor_y0;
int scissor_x1;
int scissor_y1;
CoglClipStack *entry;
int scissor_y_start;
/* If we have already flushed this state then we don't need to do
anything */
if (ctx->current_clip_stack_valid)
{
if (ctx->current_clip_stack == stack &&
(ctx->needs_viewport_scissor_workaround == FALSE ||
(framebuffer->viewport_age ==
framebuffer->viewport_age_for_scissor_workaround &&
ctx->viewport_scissor_workaround_framebuffer ==
framebuffer)))
return;
_cogl_clip_stack_unref (ctx->current_clip_stack);
}
ctx->current_clip_stack_valid = TRUE;
ctx->current_clip_stack = _cogl_clip_stack_ref (stack);
has_clip_planes =
_cogl_has_private_feature (ctx, COGL_PRIVATE_FEATURE_FOUR_CLIP_PLANES);
if (has_clip_planes)
disable_clip_planes (ctx);
GE( ctx, glDisable (GL_STENCIL_TEST) );
/* If the stack is empty then there's nothing else to do
*
* See comment below about ctx->needs_viewport_scissor_workaround
*/
if (stack == NULL && !ctx->needs_viewport_scissor_workaround)
{
COGL_NOTE (CLIPPING, "Flushed empty clip stack");
ctx->current_clip_stack_uses_stencil = FALSE;
GE (ctx, glDisable (GL_SCISSOR_TEST));
return;
}
/* Calculate the scissor rect first so that if we eventually have to
clear the stencil buffer then the clear will be clipped to the
intersection of all of the bounding boxes. This saves having to
clear the whole stencil buffer */
_cogl_clip_stack_get_bounds (stack,
&scissor_x0, &scissor_y0,
&scissor_x1, &scissor_y1);
/* XXX: ONGOING BUG: Intel viewport scissor
*
* Intel gen6 drivers don't correctly handle offset viewports, since
* primitives aren't clipped within the bounds of the viewport. To
* workaround this we push our own clip for the viewport that will
* use scissoring to ensure we clip as expected.
*
* TODO: file a bug upstream!
*/
if (ctx->needs_viewport_scissor_workaround)
{
_cogl_util_scissor_intersect (framebuffer->viewport_x,
framebuffer->viewport_y,
framebuffer->viewport_x +
framebuffer->viewport_width,
framebuffer->viewport_y +
framebuffer->viewport_height,
&scissor_x0, &scissor_y0,
&scissor_x1, &scissor_y1);
framebuffer->viewport_age_for_scissor_workaround =
framebuffer->viewport_age;
ctx->viewport_scissor_workaround_framebuffer =
framebuffer;
}
/* Enable scissoring as soon as possible */
if (scissor_x0 >= scissor_x1 || scissor_y0 >= scissor_y1)
scissor_x0 = scissor_y0 = scissor_x1 = scissor_y1 = scissor_y_start = 0;
else
{
/* We store the entry coordinates in Cogl coordinate space
* but OpenGL requires the window origin to be the bottom
* left so we may need to convert the incoming coordinates.
*
* NB: Cogl forces all offscreen rendering to be done upside
* down so in this case no conversion is needed.
*/
if (cogl_is_offscreen (framebuffer))
scissor_y_start = scissor_y0;
else
{
int framebuffer_height =
cogl_framebuffer_get_height (framebuffer);
scissor_y_start = framebuffer_height - scissor_y1;
}
}
COGL_NOTE (CLIPPING, "Flushing scissor to (%i, %i, %i, %i)",
scissor_x0, scissor_y0,
scissor_x1, scissor_y1);
GE (ctx, glEnable (GL_SCISSOR_TEST));
GE (ctx, glScissor (scissor_x0, scissor_y_start,
scissor_x1 - scissor_x0,
scissor_y1 - scissor_y0));
/* Add all of the entries. This will end up adding them in the
reverse order that they were specified but as all of the clips
are intersecting it should work out the same regardless of the
order */
for (entry = stack; entry; entry = entry->parent)
{
switch (entry->type)
{
case COGL_CLIP_STACK_PRIMITIVE:
{
CoglClipStackPrimitive *primitive_entry =
(CoglClipStackPrimitive *) entry;
COGL_NOTE (CLIPPING, "Adding stencil clip for primitive");
add_stencil_clip_primitive (framebuffer,
primitive_entry->matrix_entry,
primitive_entry->primitive,
primitive_entry->bounds_x1,
primitive_entry->bounds_y1,
primitive_entry->bounds_x2,
primitive_entry->bounds_y2,
using_stencil_buffer,
TRUE);
using_stencil_buffer = TRUE;
break;
}
case COGL_CLIP_STACK_RECT:
{
CoglClipStackRect *rect = (CoglClipStackRect *) entry;
/* We don't need to do anything extra if the clip for this
rectangle was entirely described by its scissor bounds */
if (!rect->can_be_scissor)
{
/* If we support clip planes and we haven't already used
them then use that instead */
if (has_clip_planes)
{
COGL_NOTE (CLIPPING,
"Adding clip planes clip for rectangle");
set_clip_planes (framebuffer,
rect->matrix_entry,
rect->x0,
rect->y0,
rect->x1,
rect->y1);
using_clip_planes = TRUE;
/* We can't use clip planes a second time */
has_clip_planes = FALSE;
}
else
{
COGL_NOTE (CLIPPING, "Adding stencil clip for rectangle");
add_stencil_clip_rectangle (framebuffer,
rect->matrix_entry,
rect->x0,
rect->y0,
rect->x1,
rect->y1,
!using_stencil_buffer);
using_stencil_buffer = TRUE;
}
}
break;
}
case COGL_CLIP_STACK_WINDOW_RECT:
break;
/* We don't need to do anything for window space rectangles because
* their functionality is entirely implemented by the entry bounding
* box */
}
}
/* Enabling clip planes is delayed to now so that they won't affect
setting up the stencil buffer */
if (using_clip_planes)
enable_clip_planes (ctx);
ctx->current_clip_stack_uses_stencil = using_stencil_buffer;
}