Relax multi-sampling for floating-point color renderbuffers

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

Index: third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp
diff --git a/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp b/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp
index 75809356337b366dc3d2653e2252e5034333a549..b7c4895deba062eeb31e613ccf50f94c05992442 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp
+++ b/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp
@@ -340,7 +340,6 @@ ScriptValue WebGL2RenderingContextBase::getInternalformatParameter(ScriptState*
         return ScriptValue::createNull(scriptState);
     }
 
-    bool floatType = false;
 
     switch (internalformat) {
     // Renderbuffer doesn't support unsized internal formats,
@@ -395,7 +394,6 @@ ScriptValue WebGL2RenderingContextBase::getInternalformatParameter(ScriptState*
             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");
@@ -407,20 +405,14 @@ ScriptValue WebGL2RenderingContextBase::getInternalformatParameter(ScriptState*
         {
             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));
-
-                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;
-            }
+            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());
             return WebGLAny(scriptState, DOMInt32Array::create(values.get(), length));
         }
     default:
@@ -633,6 +625,7 @@ 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:
@@ -658,6 +651,14 @@ void WebGL2RenderingContextBase::renderbufferStorageImpl(
                 "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:
@@ -673,6 +674,10 @@ void WebGL2RenderingContextBase::renderbufferStorageImpl(
     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 {
@@ -694,23 +699,6 @@ void WebGL2RenderingContextBase::renderbufferStorageImpl(
         }
         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;