1 files changed, 74 insertions, 0 deletions
diff --git a/gfx/angle/src/libANGLE/VertexAttribute.cpp b/gfx/angle/src/libANGLE/VertexAttribute.cpp
new file mode 100755
index 000000000..13d78fd13
--- /dev/null
+++ b/gfx/angle/src/libANGLE/VertexAttribute.cpp
@@ -0,0 +1,74 @@
+//
+// Copyright 2014 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Implementation of the state class for mananging GLES 3 Vertex Array Objects.
+//
+
+#include "libANGLE/VertexAttribute.h"
+
+namespace gl
+{
+
+VertexAttribute::VertexAttribute()
+    : enabled(false),
+      type(GL_FLOAT),
+      size(4),
+      normalized(false),
+      pureInteger(false),
+      stride(0),
+      pointer(NULL),
+      divisor(0)
+{
+}
+
+size_t ComputeVertexAttributeTypeSize(const VertexAttribute& attrib)
+{
+    GLuint size = attrib.size;
+    switch (attrib.type)
+    {
+      case GL_BYTE:                        return size * sizeof(GLbyte);
+      case GL_UNSIGNED_BYTE:               return size * sizeof(GLubyte);
+      case GL_SHORT:                       return size * sizeof(GLshort);
+      case GL_UNSIGNED_SHORT:              return size * sizeof(GLushort);
+      case GL_INT:                         return size * sizeof(GLint);
+      case GL_UNSIGNED_INT:                return size * sizeof(GLuint);
+      case GL_INT_2_10_10_10_REV:          return 4;
+      case GL_UNSIGNED_INT_2_10_10_10_REV: return 4;
+      case GL_FIXED:                       return size * sizeof(GLfixed);
+      case GL_HALF_FLOAT:                  return size * sizeof(GLhalf);
+      case GL_FLOAT:                       return size * sizeof(GLfloat);
+      default: UNREACHABLE();              return size * sizeof(GLfloat);
+    }
+}
+
+size_t ComputeVertexAttributeStride(const VertexAttribute& attrib)
+{
+    if (!attrib.enabled)
+    {
+        return 16;
+    }
+    return attrib.stride ? attrib.stride : ComputeVertexAttributeTypeSize(attrib);
+}
+
+size_t ComputeVertexAttributeElementCount(const VertexAttribute &attrib,
+                                          size_t drawCount,
+                                          size_t instanceCount)
+{
+    // For instanced rendering, we draw "instanceDrawCount" sets of "vertexDrawCount" vertices.
+    //
+    // A vertex attribute with a positive divisor loads one instanced vertex for every set of
+    // non-instanced vertices, and the instanced vertex index advances once every "mDivisor"
+    // instances.
+    if (instanceCount > 0 && attrib.divisor > 0)
+    {
+        // When instanceDrawCount is not a multiple attrib.divisor, the division must round up.
+        // For instance, with 5 non-instanced vertices and a divisor equal to 3, we need 2 instanced
+        // vertices.
+        return (instanceCount + attrib.divisor - 1u) / attrib.divisor;
+    }
+
+    return drawCount;
+}
+}