Implement support for mixed sampled render targets

src/gpu/gl/GrGLGpu.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLGpu.h"
 #include "GrGLStencilAttachment.h"
@@ skipping 355 matching lines @@
             // On some devices this may have a perf hit.  Also multiple render targets are disabled
             GL_CALL(Enable(GR_GL_FETCH_PER_SAMPLE_ARM));
         }
         fHWWriteToColor = kUnknown_TriState;
         // we only ever use lines in hairline mode
         GL_CALL(LineWidth(1));
     }
 
     if (resetBits & kMSAAEnable_GrGLBackendState) {
         fMSAAEnabled = kUnknown_TriState;
+        GL_CALL(CoverageModulation(GR_GL_RGBA));

[Chris Dalton, 2015/06/10 19:52:39]

We need to wrap this in a check for mixedSamplesSupport().

A comment about what it does and why it's ok to call it here seems fitting as
well.

     }
 
     fHWActiveTextureUnitIdx = -1; // invalid
 
     if (resetBits & kTextureBinding_GrGLBackendState) {
         for (int s = 0; s < fHWBoundTextureUniqueIDs.count(); ++s) {
             fHWBoundTextureUniqueIDs[s] = SK_InvalidUniqueID;
         }
     }
 
@@ skipping 111 matching lines @@
     }
 
     return texture;
 }
 
 GrRenderTarget* GrGLGpu::onWrapBackendRenderTarget(const GrBackendRenderTargetDesc& wrapDesc) {
     GrGLRenderTarget::IDDesc idDesc;
     idDesc.fRTFBOID = static_cast<GrGLuint>(wrapDesc.fRenderTargetHandle);
     idDesc.fMSColorRenderbufferID = 0;
     idDesc.fTexFBOID = GrGLRenderTarget::kUnresolvableFBOID;
+    idDesc.fSampleConfig = ((wrapDesc.fFlags & kStencilMSAAOnly_GrBackendRenderTargetFlags) &&
+                            this->caps()->shaderCaps()->mixedSamplesSupport()) ?
+                           GrRenderTarget::kStencil_SampleConfig :
+                           GrRenderTarget::kUnified_SampleConfig;

[Chris Dalton, 2015/06/10 19:52:39]

If we block the mixed samples due to it not being supported, then we need to set
the sample count to zero as well. Otherwise it will render as if both the color
and stencil buffers are multisampled.

[Chris Dalton, 2015/06/10 20:55:56]

Looks like we're taking out kStencilMSAAOnly_GrBackendRenderTargetFlags so we
can ignore that last comment. Mixed samples just won't be supported with backend
RTs.

+
     idDesc.fLifeCycle = GrGpuResource::kWrapped_LifeCycle;
 
     GrSurfaceDesc desc;
     desc.fConfig = wrapDesc.fConfig;
     desc.fFlags = kCheckAllocation_GrSurfaceFlag;
     desc.fWidth = wrapDesc.fWidth;
     desc.fHeight = wrapDesc.fHeight;
     desc.fSampleCnt = SkTMin(wrapDesc.fSampleCnt, this->caps()->maxSampleCount());
     desc.fOrigin = resolve_origin(wrapDesc.fOrigin, true);
 
@@ skipping 327 matching lines @@
 
 static bool renderbuffer_storage_msaa(const GrGLContext& ctx,
                                       int sampleCount,
                                       GrGLenum format,
                                       int width, int height) {
     CLEAR_ERROR_BEFORE_ALLOC(ctx.interface());
     SkASSERT(GrGLCaps::kNone_MSFBOType != ctx.caps()->msFBOType());
     switch (ctx.caps()->msFBOType()) {
         case GrGLCaps::kDesktop_ARB_MSFBOType:
         case GrGLCaps::kDesktop_EXT_MSFBOType:
+        case GrGLCaps::kMixedSamples_MSFBOType:
         case GrGLCaps::kES_3_0_MSFBOType:
             GL_ALLOC_CALL(ctx.interface(),
                             RenderbufferStorageMultisample(GR_GL_RENDERBUFFER,
                                                             sampleCount,
                                                             format,
                                                             width, height));
             break;
         case GrGLCaps::kES_Apple_MSFBOType:
             GL_ALLOC_CALL(ctx.interface(),
                             RenderbufferStorageMultisampleES2APPLE(GR_GL_RENDERBUFFER,
@@ skipping 17 matching lines @@
 }
 
 bool GrGLGpu::createRenderTargetObjects(const GrSurfaceDesc& desc,
                                         GrGpuResource::LifeCycle lifeCycle,
                                         GrGLuint texID,
                                         GrGLRenderTarget::IDDesc* idDesc) {
     idDesc->fMSColorRenderbufferID = 0;
     idDesc->fRTFBOID = 0;
     idDesc->fTexFBOID = 0;
     idDesc->fLifeCycle = lifeCycle;
+    idDesc->fSampleConfig = GrGLCaps::kMixedSamples_MSFBOType ==
+                            this->glCaps().msFBOType() ? GrRenderTarget::kStencil_SampleConfig :
+                                                         GrRenderTarget::kUnified_SampleConfig;
 
     GrGLenum status;
 
     GrGLenum msColorFormat = 0; // suppress warning
 
     if (desc.fSampleCnt > 0 && GrGLCaps::kNone_MSFBOType == this->glCaps().msFBOType()) {
         goto FAILED;
     }
 
     GL_CALL(GenFramebuffers(1, &idDesc->fTexFBOID));
@@ skipping 262 matching lines @@
 }
 }
 
 bool GrGLGpu::createStencilAttachmentForRenderTarget(GrRenderTarget* rt, int width, int height) {
     // All internally created RTs are also textures. We don't create
     // SBs for a client's standalone RT (that is a RT that isn't also a texture).
     SkASSERT(rt->asTexture());
     SkASSERT(width >= rt->width());
     SkASSERT(height >= rt->height());
 
-    int samples = rt->numSamples();
+    int samples = rt->numStencilSamples();
     GrGLStencilAttachment::IDDesc sbDesc;
 
     int stencilFmtCnt = this->glCaps().stencilFormats().count();
     for (int i = 0; i < stencilFmtCnt; ++i) {
         if (!sbDesc.fRenderbufferID) {
             GL_CALL(GenRenderbuffers(1, &sbDesc.fRenderbufferID));
         }
         if (!sbDesc.fRenderbufferID) {
             return false;
         }
@@ skipping 415 matching lines @@
     GrGLRenderTarget* glRT = static_cast<GrGLRenderTarget*>(renderTarget);
     if (renderTarget->getUniqueID() != fHWBoundRenderTargetUniqueID) {
         fHWBoundRenderTargetUniqueID = SK_InvalidUniqueID;
         fStats.incRenderTargetBinds();
         GL_CALL(BindFramebuffer(GR_GL_FRAMEBUFFER, glRT->renderFBOID()));
     }
     switch (this->glCaps().invalidateFBType()) {
         case GrGLCaps::kNone_InvalidateFBType:
             SkFAIL("Should never get here.");
             break;
         case GrGLCaps::kInvalidate_InvalidateFBType:

[Chris Dalton, 2015/06/11 00:02:29]

Don't forget the workaround.

  if (renderTarget->hasMixedSamples() &&
      kNVIDIA_GrGLDriver == this->glContext().driver()) {
      break; // NVIDIA will crash calling glInvalidateFramebuffer with mixed
samples.
  }

             if (0 == glRT->renderFBOID()) {
                 //  When rendering to the default framebuffer the legal values for attachments
                 //  are GL_COLOR, GL_DEPTH, GL_STENCIL, ... rather than the various FBO attachment
                 //  types.
                 static const GrGLenum attachments[] = { GR_GL_COLOR };
                 GL_CALL(InvalidateFramebuffer(GR_GL_FRAMEBUFFER, SK_ARRAY_COUNT(attachments),
                         attachments));
             } else {
                 static const GrGLenum attachments[] = { GR_GL_COLOR_ATTACHMENT0 };
                 GL_CALL(InvalidateFramebuffer(GR_GL_FRAMEBUFFER, SK_ARRAY_COUNT(attachments),
@@ skipping 463 matching lines @@
                                stencilSettings,
                                GR_GL_FRONT_AND_BACK,
                                GrStencilSettings::kFront_Face);
             }
         }
         fHWStencilSettings = stencilSettings;
     }
 }
 
 void GrGLGpu::flushHWAAState(GrRenderTarget* rt, bool useHWAA) {
-    SkASSERT(!useHWAA || rt->isMultisampled());
+    SkASSERT(!useHWAA || rt->isStencilBufferMultisampled());
 
     if (this->glCaps().multisampleDisableSupport()) {
         if (useHWAA) {
             if (kYes_TriState != fMSAAEnabled) {
                 GL_CALL(Enable(GR_GL_MULTISAMPLE));
                 fMSAAEnabled = kYes_TriState;
             }
         } else {
             if (kNo_TriState != fMSAAEnabled) {
                 GL_CALL(Disable(GR_GL_MULTISAMPLE));
@@ skipping 963 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }