Add support for GL_EXT_multisampled_render_to_texture.

src/gpu/gl/GrGpuGL.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 "GrGpuGL.h"
 #include "GrGLStencilBuffer.h"
@@ skipping 763 matching lines @@
                                         GrGLRenderTarget::Desc* desc) {
     desc->fMSColorRenderbufferID = 0;
     desc->fRTFBOID = 0;
     desc->fTexFBOID = 0;
     desc->fIsWrapped = false;
 
     GrGLenum status;
 
     GrGLenum msColorFormat = 0; // suppress warning
 
+    if (desc->fSampleCnt > 0 && GrGLCaps::kNone_MSFBOType == this->glCaps().msFBOType()) {
+        goto FAILED;
+    }
+
     GL_CALL(GenFramebuffers(1, &desc->fTexFBOID));
     if (!desc->fTexFBOID) {
         goto FAILED;
     }
 
 
     // If we are using multisampling we will create two FBOS. We render to one and then resolve to
     // the texture bound to the other. The exception is the IMG multisample extension. With this
     // extension the texture is multisampled when rendered to and then auto-resolves it when it is
     // rendered from.
-    if (desc->fSampleCnt > 0 && GrGLCaps::kImaginationES_MSFBOType != this->glCaps().msFBOType()) {
-        if (GrGLCaps::kNone_MSFBOType == this->glCaps().msFBOType()) {
-            goto FAILED;
-        }
+    if (desc->fSampleCnt > 0 && this->glCaps().usesMSAARenderBuffers()) {
         GL_CALL(GenFramebuffers(1, &desc->fRTFBOID));
         GL_CALL(GenRenderbuffers(1, &desc->fMSColorRenderbufferID));
         if (!desc->fRTFBOID ||
             !desc->fMSColorRenderbufferID ||
             !this->configToGLFormats(desc->fConfig,
                                      // GLES requires sized internal formats
                                      kES2_GrGLBinding == this->glBinding(),
-                                     &msColorFormat, NULL, NULL)) {
+                                     &msColorFormat,
+                                     NULL,
+                                     NULL)) {
             goto FAILED;
         }
     } else {
         desc->fRTFBOID = desc->fTexFBOID;
     }
 
     // below here we may bind the FBO
     fHWBoundRenderTarget = NULL;
     if (desc->fRTFBOID != desc->fTexFBOID) {
         GrAssert(desc->fSampleCnt > 0);
@@ skipping 13 matching lines @@
         if (!this->glCaps().isConfigVerifiedColorAttachment(desc->fConfig)) {
             GL_CALL_RET(status, CheckFramebufferStatus(GR_GL_FRAMEBUFFER));
             if (status != GR_GL_FRAMEBUFFER_COMPLETE) {
                 goto FAILED;
             }
             fGLContext.info().caps()->markConfigAsValidColorAttachment(desc->fConfig);
         }
     }
     GL_CALL(BindFramebuffer(GR_GL_FRAMEBUFFER, desc->fTexFBOID));
 
-    if (GrGLCaps::kImaginationES_MSFBOType == this->glCaps().msFBOType() && desc->fSampleCnt > 0) {
+    if (this->glCaps().usesImplicitMSAAResolve() && desc->fSampleCnt > 0) {
         GL_CALL(FramebufferTexture2DMultisample(GR_GL_FRAMEBUFFER,
                                                 GR_GL_COLOR_ATTACHMENT0,
                                                 GR_GL_TEXTURE_2D,
                                                 texID, 0, desc->fSampleCnt));
     } else {
         GL_CALL(FramebufferTexture2D(GR_GL_FRAMEBUFFER,
                                      GR_GL_COLOR_ATTACHMENT0,
                                      GR_GL_TEXTURE_2D,
                                      texID, 0));
     }
@@ skipping 824 matching lines @@
             GrCrash("Unexpected path fill.");
             return; // suppress unused var warning.
     }
     GrGLint writeMask = fStencilSettings.writeMask(GrStencilSettings::kFront_Face);
     GL_CALL(StencilFillPath(id, fillMode, writeMask));
 }
 
 void GrGpuGL::onResolveRenderTarget(GrRenderTarget* target) {
     GrGLRenderTarget* rt = static_cast<GrGLRenderTarget*>(target);
     if (rt->needsResolve()) {
-        // The IMG extension automatically resolves the texture when it is read.
-        if (GrGLCaps::kImaginationES_MSFBOType != this->glCaps().msFBOType()) {
-            GrAssert(GrGLCaps::kNone_MSFBOType != this->glCaps().msFBOType());
+        // Some extensions automatically resolves the texture when it is read.
+        if (this->glCaps().usesMSAARenderBuffers()) {
             GrAssert(rt->textureFBOID() != rt->renderFBOID());
             GL_CALL(BindFramebuffer(GR_GL_READ_FRAMEBUFFER, rt->renderFBOID()));
             GL_CALL(BindFramebuffer(GR_GL_DRAW_FRAMEBUFFER, rt->textureFBOID()));
             // make sure we go through flushRenderTarget() since we've modified
             // the bound DRAW FBO ID.
             fHWBoundRenderTarget = NULL;
             const GrGLIRect& vp = rt->getViewport();
             const GrIRect dirtyRect = rt->getResolveRect();
             GrGLIRect r;
             r.setRelativeTo(vp, dirtyRect.fLeft, dirtyRect.fTop,
                             dirtyRect.width(), dirtyRect.height(), target->origin());
 
             GrAutoTRestore<ScissorState> asr;
-            if (GrGLCaps::kAppleES_MSFBOType == this->glCaps().msFBOType()) {
+            if (GrGLCaps::kES_Apple_MSFBOType == this->glCaps().msFBOType()) {
                 // Apple's extension uses the scissor as the blit bounds.
                 asr.reset(&fScissorState);
                 fScissorState.fEnabled = true;
                 fScissorState.fRect = dirtyRect;
                 this->flushScissor();
                 GL_CALL(ResolveMultisampleFramebuffer());
             } else {
-                if (GrGLCaps::kDesktopARB_MSFBOType != this->glCaps().msFBOType()) {
+                if (GrGLCaps::kDesktop_EXT_MSFBOType == this->glCaps().msFBOType()) {
                     // this respects the scissor during the blit, so disable it.
-                    GrAssert(GrGLCaps::kDesktopEXT_MSFBOType == this->glCaps().msFBOType());
                     asr.reset(&fScissorState);
                     fScissorState.fEnabled = false;
                     this->flushScissor();
                 }
                 int right = r.fLeft + r.fWidth;
                 int top = r.fBottom + r.fHeight;
                 GL_CALL(BlitFramebuffer(r.fLeft, r.fBottom, right, top,
                                         r.fLeft, r.fBottom, right, top,
                                         GR_GL_COLOR_BUFFER_BIT, GR_GL_NEAREST));
             }
@@ skipping 505 matching lines @@
         fHWActiveTextureUnitIdx = SPARE_TEX_UNIT;
     }
 }
 
 namespace {
 // Determines whether glBlitFramebuffer could be used between src and dst.
 inline bool can_blit_framebuffer(const GrSurface* dst,
                                  const GrSurface* src,
                                  const GrGpuGL* gpu,
                                  bool* wouldNeedTempFBO = NULL) {
-    if (gpu->isConfigRenderable(dst->config()) && gpu->isConfigRenderable(src->config()) &&
-        (GrGLCaps::kDesktopEXT_MSFBOType == gpu->glCaps().msFBOType() ||
-         GrGLCaps::kDesktopARB_MSFBOType == gpu->glCaps().msFBOType())) {
+    if (gpu->isConfigRenderable(dst->config()) &&
+        gpu->isConfigRenderable(src->config()) &&
+        gpu->glCaps().usesMSAARenderBuffers()) {
         if (NULL != wouldNeedTempFBO) {
             *wouldNeedTempFBO = NULL == dst->asRenderTarget() || NULL == src->asRenderTarget();
         }
         return true;
     } else {
         return false;
     }
 }
 
 inline bool can_copy_texsubimage(const GrSurface* dst,
@@ skipping 155 matching lines @@
                                     srcRect.height(),
                                     src->origin());
             dstGLRect.setRelativeTo(dstVP,
                                     dstRect.fLeft,
                                     dstRect.fTop,
                                     dstRect.width(),
                                     dstRect.height(),
                                     dst->origin());
 
             GrAutoTRestore<ScissorState> asr;
-            if (GrGLCaps::kDesktopEXT_MSFBOType == this->glCaps().msFBOType()) {
+            if (GrGLCaps::kDesktop_EXT_MSFBOType == this->glCaps().msFBOType()) {
                 // The EXT version applies the scissor during the blit, so disable it.
                 asr.reset(&fScissorState);
                 fScissorState.fEnabled = false;
                 this->flushScissor();
             }
             GrGLint srcY0;
             GrGLint srcY1;
             // Does the blit need to y-mirror or not?
             if (src->origin() == dst->origin()) {
                 srcY0 = srcGLRect.fBottom;
@@ skipping 76 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }