Optimized non-static usage of static buffers.

src/libGLESv2/Buffer.cpp

@@ -75,8 +75,11 @@ void Buffer::bufferSubData(const void *data, GLsizeiptr size, GLintptr offset)
 
         if (mUsage == GL_STATIC_DRAW)
         {
-            mVertexBuffer = new StaticVertexBuffer(getDevice());
-            mIndexBuffer = new StaticIndexBuffer(getDevice());
+            // If applications update the buffer data after it has already been used in a draw call,
+            // it most likely isn't used as a static buffer so we should fall back to streaming usage
+            // for best performance. So ignore the usage hint and don't create new static buffers.
+        //  mVertexBuffer = new StaticVertexBuffer(getDevice());
+        //  mIndexBuffer = new StaticIndexBuffer(getDevice());
         }
     }
 }

src/libGLESv2/geometry/IndexDataManager.cpp

@@ -156,9 +156,14 @@ GLenum IndexDataManager::prepareIndexData(GLenum type, GLsizei count, Buffer *bu
             }
         }
 
-        indexBuffer->reserveSpace(convertCount * indexSize(format), type);
-
-        void *output = indexBuffer->map(indexSize(format) * convertCount, &streamOffset);
+        void *output = NULL;
+        
+        if (indexBuffer)
+        {
+            indexBuffer->reserveSpace(convertCount * indexSize(format), type);
+            output = indexBuffer->map(indexSize(format) * convertCount, &streamOffset);
+        }
+        
         if (output == NULL)
         {
             ERR("Failed to map index buffer.");

src/libGLESv2/geometry/VertexDataManager.cpp

@@ -59,7 +59,12 @@ UINT VertexDataManager::writeAttributeData(ArrayVertexBuffer *vertexBuffer, GLin
     const FormatConverter &converter = formatConverter(attribute);
     UINT streamOffset = 0;
 
-    void *output = vertexBuffer->map(attribute, spaceRequired(attribute, count), &streamOffset);
+    void *output = NULL;
+    
+    if (vertexBuffer)
+    {
+        output = vertexBuffer->map(attribute, spaceRequired(attribute, count), &streamOffset);
+    }
 
     if (output == NULL)
     {
@@ -123,7 +128,10 @@ GLenum VertexDataManager::prepareVertexData(GLint start, GLsizei count, Translat
             }
             else if (!staticBuffer || staticBuffer->lookupAttribute(attribs[i]) == -1)
             {
-                mStreamingBuffer->addRequiredSpace(spaceRequired(attribs[i], count));
+                if (mStreamingBuffer)
+                {
+                    mStreamingBuffer->addRequiredSpace(spaceRequired(attribs[i], count));
+                }
             }
         }
     }
@@ -153,7 +161,7 @@ GLenum VertexDataManager::prepareVertexData(GLint start, GLsizei count, Translat
                     }
                 }
 
-                if (!matchingAttributes)
+                if (!matchingAttributes && mStreamingBuffer)
                 {
                     mStreamingBuffer->addRequiredSpaceFor(staticBuffer);
                     buffer->invalidateStaticData();
@@ -172,7 +180,10 @@ GLenum VertexDataManager::prepareVertexData(GLint start, GLsizei count, Translat
             ArrayVertexBuffer *staticBuffer = buffer ? buffer->getVertexBuffer() : NULL;
             ArrayVertexBuffer *vertexBuffer = staticBuffer ? staticBuffer : mStreamingBuffer;
 
-            vertexBuffer->reserveRequiredSpace();
+            if (vertexBuffer)
+            {
+                vertexBuffer->reserveRequiredSpace();
+            }
         }
     }