cogl: Remove viewport scissor workaround

This is effectively a revert of:

    commit 6cfc93f26f
    Author: Robert Bragg <robert@linux.intel.com>
    Date:   Tue Oct 2 11:44:00 2012 +0100

        clip-stack: workaround intel gen6 viewport clip bug

It's been over six years, if this bug is still present we should just
fix Mesa already.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/481
This commit is contained in:
Adam Jackson 2019-03-06 12:34:36 -05:00 committed by Georges Basile Stavracas Neto
parent e3f3274bbf
commit b624e94ab1
4 changed files with 4 additions and 120 deletions

View File

@ -103,9 +103,6 @@ struct _CoglContext
unsigned long private_features
[COGL_FLAGS_N_LONGS_FOR_SIZE (COGL_N_PRIVATE_FEATURES)];
gboolean needs_viewport_scissor_workaround;
CoglFramebuffer *viewport_scissor_workaround_framebuffer;
CoglPipeline *default_pipeline;
CoglPipelineLayer *default_layer_0;
CoglPipelineLayer *default_layer_n;

View File

@ -265,22 +265,6 @@ cogl_context_new (CoglDisplay *display,
/* Initialise the driver specific state */
_cogl_init_feature_overrides (context);
/* XXX: ONGOING BUG: Intel viewport scissor
*
* Intel gen6 drivers don't currently 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 (context->gpu.driver_package == COGL_GPU_INFO_DRIVER_PACKAGE_MESA &&
context->gpu.architecture == COGL_GPU_INFO_ARCHITECTURE_SANDYBRIDGE &&
!getenv ("COGL_DISABLE_INTEL_VIEWPORT_SCISSORT_WORKAROUND"))
context->needs_viewport_scissor_workaround = TRUE;
else
context->needs_viewport_scissor_workaround = FALSE;
context->sampler_cache = _cogl_sampler_cache_new (context);
_cogl_pipeline_init_default_pipeline ();

View File

@ -191,9 +191,6 @@ _cogl_framebuffer_free (CoglFramebuffer *framebuffer)
cogl_object_unref (framebuffer->journal);
if (ctx->viewport_scissor_workaround_framebuffer == framebuffer)
ctx->viewport_scissor_workaround_framebuffer = NULL;
ctx->framebuffers = g_list_remove (ctx->framebuffers, framebuffer);
if (ctx->current_draw_buffer == framebuffer)
@ -260,13 +257,11 @@ cogl_framebuffer_clear4f (CoglFramebuffer *framebuffer,
float blue,
float alpha)
{
CoglContext *ctx = framebuffer->context;
CoglClipStack *clip_stack = _cogl_framebuffer_get_clip_stack (framebuffer);
int scissor_x0;
int scissor_y0;
int scissor_x1;
int scissor_y1;
gboolean saved_viewport_scissor_workaround;
if (!framebuffer->depth_buffer_clear_needed &&
(buffers & COGL_BUFFER_BIT_DEPTH))
@ -361,31 +356,6 @@ cogl_framebuffer_clear4f (CoglFramebuffer *framebuffer,
_cogl_framebuffer_flush_journal (framebuffer);
/* XXX: ONGOING BUG: Intel viewport scissor
*
* The semantics of cogl_framebuffer_clear() are that it should not
* be affected by the current viewport and so if we are currently
* applying a workaround for viewport scissoring we need to
* temporarily disable the workaround before clearing so any
* special scissoring for the workaround will be removed first.
*
* Note: we only need to disable the workaround if the current
* viewport doesn't match the framebuffer's size since otherwise
* the workaround wont affect clearing anyway.
*/
if (ctx->needs_viewport_scissor_workaround &&
(framebuffer->viewport_x != 0 ||
framebuffer->viewport_y != 0 ||
framebuffer->viewport_width != framebuffer->width ||
framebuffer->viewport_height != framebuffer->height))
{
saved_viewport_scissor_workaround = TRUE;
ctx->needs_viewport_scissor_workaround = FALSE;
ctx->current_draw_buffer_changes |= COGL_FRAMEBUFFER_STATE_CLIP;
}
else
saved_viewport_scissor_workaround = FALSE;
/* NB: _cogl_framebuffer_flush_state may disrupt various state (such
* as the pipeline state) when flushing the clip stack, so should
* always be done first when preparing to draw. */
@ -395,16 +365,6 @@ cogl_framebuffer_clear4f (CoglFramebuffer *framebuffer,
_cogl_framebuffer_clear_without_flush4f (framebuffer, buffers,
red, green, blue, alpha);
/* XXX: ONGOING BUG: Intel viewport scissor
*
* See comment about temporarily disabling this workaround above
*/
if (saved_viewport_scissor_workaround)
{
ctx->needs_viewport_scissor_workaround = TRUE;
ctx->current_draw_buffer_changes |= COGL_FRAMEBUFFER_STATE_CLIP;
}
/* This is a debugging variable used to visually display the quad
* batches from the journal. It is reset here to increase the
* chances of getting the same colours for each frame during an
@ -552,12 +512,7 @@ cogl_framebuffer_set_viewport (CoglFramebuffer *framebuffer,
framebuffer->viewport_age++;
if (context->current_draw_buffer == framebuffer)
{
context->current_draw_buffer_changes |= COGL_FRAMEBUFFER_STATE_VIEWPORT;
if (context->needs_viewport_scissor_workaround)
context->current_draw_buffer_changes |= COGL_FRAMEBUFFER_STATE_CLIP;
}
context->current_draw_buffer_changes |= COGL_FRAMEBUFFER_STATE_VIEWPORT;
}
float
@ -831,27 +786,7 @@ _cogl_framebuffer_compare_viewport_state (CoglFramebuffer *a,
/* NB: we render upside down to offscreen framebuffers and that
* can affect how we setup the GL viewport... */
a->type != b->type)
{
unsigned long differences = COGL_FRAMEBUFFER_STATE_VIEWPORT;
CoglContext *context = a->context;
/* XXX: ONGOING BUG: Intel viewport scissor
*
* Intel gen6 drivers don't currently 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.
*
* This workaround implies that a change in viewport state is
* effectively also a change in the clipping state.
*
* TODO: file a bug upstream!
*/
if (G_UNLIKELY (context->needs_viewport_scissor_workaround))
differences |= COGL_FRAMEBUFFER_STATE_CLIP;
return differences;
}
return COGL_FRAMEBUFFER_STATE_VIEWPORT;
else
return 0;
}

View File

@ -435,12 +435,7 @@ _cogl_clip_stack_gl_flush (CoglClipStack *stack,
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)))
if (ctx->current_clip_stack == stack)
return;
_cogl_clip_stack_unref (ctx->current_clip_stack);
@ -457,10 +452,8 @@ _cogl_clip_stack_gl_flush (CoglClipStack *stack,
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)
if (stack == NULL)
{
COGL_NOTE (CLIPPING, "Flushed empty clip stack");
@ -477,31 +470,6 @@ _cogl_clip_stack_gl_flush (CoglClipStack *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;