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//
// 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 classes for mananging GLES 3.1 Vertex Array Objects.
//
#include "libANGLE/VertexAttribute.h"
namespace gl
{
// [OpenGL ES 3.1] (November 3, 2016) Section 20 Page 361
// Table 20.2: Vertex Array Object State
VertexBinding::VertexBinding() : mStride(16u), mDivisor(0), mOffset(0)
{
}
VertexBinding::VertexBinding(VertexBinding &&binding)
{
*this = std::move(binding);
}
VertexBinding::~VertexBinding()
{
}
VertexBinding &VertexBinding::operator=(VertexBinding &&binding)
{
if (this != &binding)
{
mStride = binding.mStride;
mDivisor = binding.mDivisor;
mOffset = binding.mOffset;
std::swap(binding.mBuffer, mBuffer);
}
return *this;
}
VertexAttribute::VertexAttribute(GLuint bindingIndex)
: enabled(false),
type(GL_FLOAT),
size(4u),
normalized(false),
pureInteger(false),
pointer(nullptr),
relativeOffset(0),
vertexAttribArrayStride(0),
bindingIndex(bindingIndex)
{
}
VertexAttribute::VertexAttribute(VertexAttribute &&attrib)
: enabled(attrib.enabled),
type(attrib.type),
size(attrib.size),
normalized(attrib.normalized),
pureInteger(attrib.pureInteger),
pointer(attrib.pointer),
relativeOffset(attrib.relativeOffset),
vertexAttribArrayStride(attrib.vertexAttribArrayStride),
bindingIndex(attrib.bindingIndex)
{
}
VertexAttribute &VertexAttribute::operator=(VertexAttribute &&attrib)
{
if (this != &attrib)
{
enabled = attrib.enabled;
type = attrib.type;
size = attrib.size;
normalized = attrib.normalized;
pureInteger = attrib.pureInteger;
pointer = attrib.pointer;
relativeOffset = attrib.relativeOffset;
vertexAttribArrayStride = attrib.vertexAttribArrayStride;
bindingIndex = attrib.bindingIndex;
}
return *this;
}
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, const VertexBinding &binding)
{
// In ES 3.1, VertexAttribPointer will store the type size in the binding stride.
// Hence, rendering always uses the binding's stride.
return attrib.enabled ? binding.getStride() : 16u;
}
// Warning: you should ensure binding really matches attrib.bindingIndex before using this function.
GLintptr ComputeVertexAttributeOffset(const VertexAttribute &attrib, const VertexBinding &binding)
{
return attrib.relativeOffset + binding.getOffset();
}
size_t ComputeVertexBindingElementCount(GLuint divisor, 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 && 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 + divisor - 1u) / divisor;
}
return drawCount;
}
GLenum GetVertexAttributeBaseType(const VertexAttribute &attrib)
{
if (attrib.pureInteger)
{
switch (attrib.type)
{
case GL_BYTE:
case GL_SHORT:
case GL_INT:
return GL_INT;
case GL_UNSIGNED_BYTE:
case GL_UNSIGNED_SHORT:
case GL_UNSIGNED_INT:
return GL_UNSIGNED_INT;
default:
UNREACHABLE();
return GL_NONE;
}
}
else
{
return GL_FLOAT;
}
}
} // namespace gl
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