Relax multi-sampling for floating-point color renderbuffers

third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/webgl/WebGL2RenderingContextBase.h"
 
 #include "bindings/modules/v8/WebGLAny.h"
 #include "core/frame/ImageBitmap.h"
 #include "core/html/HTMLCanvasElement.h"
 #include "core/html/HTMLImageElement.h"
@@ skipping 322 matching lines @@
 ScriptValue WebGL2RenderingContextBase::getInternalformatParameter(ScriptState* scriptState, GLenum target, GLenum internalformat, GLenum pname)
 {
     if (isContextLost())
         return ScriptValue::createNull(scriptState);
 
     if (target != GL_RENDERBUFFER) {
         synthesizeGLError(GL_INVALID_ENUM, "getInternalformatParameter", "invalid target");
         return ScriptValue::createNull(scriptState);
     }
 
-    bool floatType = false;
 
     switch (internalformat) {
     // Renderbuffer doesn't support unsized internal formats,
     // though GL_RGB and GL_RGBA are color-renderable.
     case GL_RGB:
     case GL_RGBA:
     // Multisampling is not supported for signed and unsigned integer internal formats.
     case GL_R8UI:
     case GL_R8I:
     case GL_R16UI:
@@ skipping 34 matching lines @@
     case GL_RG16F:
     case GL_RGBA16F:
     case GL_R32F:
     case GL_RG32F:
     case GL_RGBA32F:
     case GL_R11F_G11F_B10F:
         if (!extensionEnabled(EXTColorBufferFloatName)) {
             synthesizeGLError(GL_INVALID_ENUM, "getInternalformatParameter", "invalid internalformat when EXT_color_buffer_float is not enabled");
             return ScriptValue::createNull(scriptState);
         }
-        floatType = true;
         break;
     default:
         synthesizeGLError(GL_INVALID_ENUM, "getInternalformatParameter", "invalid internalformat");
         return ScriptValue::createNull(scriptState);
     }
 
     switch (pname) {
     case GL_SAMPLES:
         {
             std::unique_ptr<GLint[]> values;
             GLint length = -1;
-            if (!floatType) {
-                contextGL()->GetInternalformativ(target, internalformat, GL_NUM_SAMPLE_COUNTS, 1, &length);
-                if (length <= 0)
-                    return WebGLAny(scriptState, DOMInt32Array::create(0));
+            contextGL()->GetInternalformativ(target, internalformat, GL_NUM_SAMPLE_COUNTS, 1, &length);
+            if (length <= 0)
+                return WebGLAny(scriptState, DOMInt32Array::create(0));
 
-                values = wrapArrayUnique(new GLint[length]);
-                for (GLint ii = 0; ii < length; ++ii)
-                    values[ii] = 0;
-                contextGL()->GetInternalformativ(target, internalformat, GL_SAMPLES, length, values.get());
-            } else {
-                length = 1;
-                values = wrapArrayUnique(new GLint[1]);
-                values[0] = 1;
-            }
+            values = wrapArrayUnique(new GLint[length]);
+            for (GLint ii = 0; ii < length; ++ii)
+                values[ii] = 0;
+            contextGL()->GetInternalformativ(target, internalformat, GL_SAMPLES, length, values.get());
             return WebGLAny(scriptState, DOMInt32Array::create(values.get(), length));
         }
     default:
         synthesizeGLError(GL_INVALID_ENUM, "getInternalformatParameter", "invalid parameter name");
         return ScriptValue::createNull(scriptState);
     }
 }
 
 bool WebGL2RenderingContextBase::checkAndTranslateAttachments(const char* functionName, GLenum target, Vector<GLenum>& attachments)
 {
@@ skipping 192 matching lines @@
     {
         ScopedDrawingBufferBinder binder(drawingBuffer(), framebuffer);
         contextGL()->ReadPixels(x, y, width, height, format, type, reinterpret_cast<void*>(offset));
     }
 }
 
 void WebGL2RenderingContextBase::renderbufferStorageImpl(
     GLenum target, GLsizei samples, GLenum internalformat, GLsizei width, GLsizei height,
     const char* functionName)
 {
+    bool floatType = false;
     switch (internalformat) {
     case GL_R8UI:
     case GL_R8I:
     case GL_R16UI:
     case GL_R16I:
     case GL_R32UI:
     case GL_R32I:
     case GL_RG8UI:
     case GL_RG8I:
     case GL_RG16UI:
     case GL_RG16I:
     case GL_RG32UI:
     case GL_RG32I:
     case GL_RGBA8UI:
     case GL_RGBA8I:
     case GL_RGB10_A2UI:
     case GL_RGBA16UI:
     case GL_RGBA16I:
     case GL_RGBA32UI:
     case GL_RGBA32I:
         if (samples > 0) {
             synthesizeGLError(GL_INVALID_OPERATION, functionName,
                 "for integer formats, samples > 0");
             return;
         }
+    case GL_R16F:
+    case GL_RG16F:
+    case GL_RGBA16F:
+    case GL_R32F:
+    case GL_RG32F:
+    case GL_RGBA32F:
+    case GL_R11F_G11F_B10F:
+        floatType = true;

[yunchao, 2016/08/01 02:49:42]

The fall-through code here will be executed for integer internalformat above. It
is not correct. 

     case GL_R8:
     case GL_RG8:
     case GL_RGB8:
     case GL_RGB565:
     case GL_RGBA8:
     case GL_SRGB8_ALPHA8:
     case GL_RGB5_A1:
     case GL_RGBA4:
     case GL_RGB10_A2:
     case GL_DEPTH_COMPONENT16:
     case GL_DEPTH_COMPONENT24:
     case GL_DEPTH_COMPONENT32F:
     case GL_DEPTH24_STENCIL8:
     case GL_DEPTH32F_STENCIL8:
     case GL_STENCIL_INDEX8:
+        if (floatType && !extensionEnabled(EXTColorBufferFloatName)) {
+            synthesizeGLError(GL_INVALID_ENUM, functionName, "EXT_color_buffer_float not enabled");
+            return;
+        }
         if (!samples) {
             contextGL()->RenderbufferStorage(target, internalformat, width, height);
         } else {
             GLint maxNumberOfSamples = 0;
             contextGL()->GetInternalformativ(target, internalformat, GL_SAMPLES, 1, &maxNumberOfSamples);
             if (samples > maxNumberOfSamples) {
                 synthesizeGLError(GL_INVALID_OPERATION, functionName, "samples out of range");
                 return;
             }
             contextGL()->RenderbufferStorageMultisampleCHROMIUM(
                 target, samples, internalformat, width, height);
         }
         break;
     case GL_DEPTH_STENCIL:
         // To be WebGL 1 backward compatible.
         if (samples > 0) {
             synthesizeGLError(GL_INVALID_ENUM, functionName, "invalid internalformat");
             return;
         }
         contextGL()->RenderbufferStorage(target, GL_DEPTH24_STENCIL8, width, height);
         break;
-    case GL_R16F:
-    case GL_RG16F:
-    case GL_RGBA16F:
-    case GL_R32F:
-    case GL_RG32F:
-    case GL_RGBA32F:
-    case GL_R11F_G11F_B10F:
-        if (!extensionEnabled(EXTColorBufferFloatName)) {
-            synthesizeGLError(GL_INVALID_ENUM, functionName, "EXT_color_buffer_float not enabled");
-            return;
-        }
-        if (samples) {
-            synthesizeGLError(GL_INVALID_VALUE, functionName, "multisampled float buffers not supported");
-            return;
-        }
-        contextGL()->RenderbufferStorage(target, internalformat, width, height);
-        break;
     default:
         synthesizeGLError(GL_INVALID_ENUM, functionName, "invalid internalformat");
         return;
     }
     m_renderbufferBinding->setInternalFormat(internalformat);
     m_renderbufferBinding->setSize(width, height);
 }
 
 void WebGL2RenderingContextBase::renderbufferStorageMultisample(GLenum target, GLsizei samples, GLenum internalformat, GLsizei width, GLsizei height)
 {
@@ skipping 2645 matching lines @@
     params.skipPixels = m_unpackSkipPixels;
     params.skipRows = m_unpackSkipRows;
     if (dimension == Tex3D) {
         params.imageHeight = m_unpackImageHeight;
         params.skipImages = m_unpackSkipImages;
     }
     return params;
 }
 
 } // namespace blink