blender/intern/cycles/render/constant_fold.h
Alexander Gavrilov 40eedd5df9 Cycles: implement partial constant folding for exponentiation.
This is also an important mathematical operation that can be folded
if it is known that one argument is a certain constant. For colors
the operation is provided as a Gamma node.

The SVM Gamma node needs a small fix to make it follow the 0 ^ 0 == 1
rule, same as the Power node, or the Gamma node itself in OSL mode.

Reviewers: #cycles

Differential Revision: https://developer.blender.org/D2263
2016-10-01 14:37:03 +03:00

72 lines
2.1 KiB
C++

/*
* Copyright 2011-2013 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __CONSTANT_FOLD_H__
#define __CONSTANT_FOLD_H__
#include "util_types.h"
#include "svm_types.h"
CCL_NAMESPACE_BEGIN
class ShaderGraph;
class ShaderInput;
class ShaderNode;
class ShaderOutput;
class ConstantFolder {
public:
ShaderGraph *const graph;
ShaderNode *const node;
ShaderOutput *const output;
ConstantFolder(ShaderGraph *graph, ShaderNode *node, ShaderOutput *output);
bool all_inputs_constant() const;
/* Constant folding helpers */
void make_constant(float value) const;
void make_constant(float3 value) const;
void make_constant_clamp(float value, bool clamp) const;
void make_constant_clamp(float3 value, bool clamp) const;
void make_zero() const;
void make_one() const;
/* Bypass node, relinking to another output socket. */
void bypass(ShaderOutput *output) const;
/* For closure nodes, discard node entirely or bypass to one of its inputs. */
void discard() const;
void bypass_or_discard(ShaderInput *input) const;
/* Bypass or make constant, unless we can't due to clamp being true. */
bool try_bypass_or_make_constant(ShaderInput *input, bool clamp = false) const;
/* Test if shader inputs of the current nodes have fixed values. */
bool is_zero(ShaderInput *input) const;
bool is_one(ShaderInput *input) const;
/* Specific nodes. */
void fold_mix(NodeMix type, bool clamp) const;
void fold_math(NodeMath type, bool clamp) const;
void fold_vector_math(NodeVectorMath type) const;
};
CCL_NAMESPACE_END
#endif /* __CONSTANT_FOLD_H__ */