Hash :
a977acc8
Author :
Date :
2018-09-19T12:46:05
ES31: Support translating textureGather into HLSL - Part I
This patch is the first one in the series of supporting GLSL texture
function textureGather/textureGatherOffset on D3D11.
According to ESSL 3.1 SPEC (Chapter 8.9.3, Page 130), the definition
of textureGather on sampler2D is:
gvec4 textureGather (gsampler2D sampler, vec2 P[, int comp])
The parameter "comp" is optional, and if it is specified, the value
of "comp" must be a constant integer expression with a value of 0, 1,
2, or 3, identifying the x, y, z, or w postswizzled component of the
four-component vector lookup result for each texel, respectively. If
comp is not specified, it is treated as 0.
According to the definition above, textureGather is equivalent to
Texture2D.Gather[Red|Green|Blue|Alpha] in HLSL, where we can use a
switch-case expression to choose the right HLSL texture function.
The features listed here will be implemented in the following patches:
1. Support textureGatherOffset
2. Support textureGather[Offset] on isamplers and usamplers
3. Support textureGather[Offset] on textures when swizzle is on
4. Support textureGather[Offset] on shadow samplers
BUG=angleproject:2826
TEST=dEQP-GLES31.functional.texture.gather.basic.2d.rgba8.*
dEQP-GLES31.functional.texture.gather.basic.cube.rgba8.*
(without texture_swizzle)
dEQP-GLES31.functional.texture.gather.basic.2d_array.rgba8.*
(without texture_swizzle)
Change-Id: Iff2ed4f8b65dad613cb0bafdfd19f8f0528e832c
Reviewed-on: https://chromium-review.googlesource.com/1232980
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
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//
// Copyright (c) 2016 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.
//
// TextureFunctionHLSL: Class for writing implementations of ESSL texture functions into HLSL
// output. Some of the implementations are straightforward and just call the HLSL equivalent of the
// ESSL texture function, others do more work to emulate ESSL texture sampling or size query
// behavior.
//
#ifndef COMPILER_TRANSLATOR_TEXTUREFUNCTIONHLSL_H_
#define COMPILER_TRANSLATOR_TEXTUREFUNCTIONHLSL_H_
#include <set>
#include "compiler/translator/BaseTypes.h"
#include "compiler/translator/Common.h"
#include "compiler/translator/InfoSink.h"
#include "GLSLANG/ShaderLang.h"
namespace sh
{
class TextureFunctionHLSL final : angle::NonCopyable
{
public:
struct TextureFunction
{
// See ESSL 3.00.6 section 8.8 for reference about what the different methods below do.
enum Method
{
IMPLICIT, // Mipmap LOD determined implicitly (standard lookup)
BIAS,
LOD,
LOD0,
LOD0BIAS,
SIZE, // textureSize()
FETCH,
GRAD,
GATHER
};
ImmutableString name() const;
bool operator<(const TextureFunction &rhs) const;
const char *getReturnType() const;
TBasicType sampler;
int coords;
bool proj;
bool offset;
Method method;
};
// Returns the name of the texture function implementation to call.
// The name that's passed in is the name of the GLSL texture function that it should implement.
ImmutableString useTextureFunction(const ImmutableString &name,
TBasicType samplerType,
int coords,
size_t argumentCount,
bool lod0,
sh::GLenum shaderType);
void textureFunctionHeader(TInfoSinkBase &out,
const ShShaderOutput outputType,
bool getDimensionsIgnoresBaseLevel);
private:
typedef std::set<TextureFunction> TextureFunctionSet;
TextureFunctionSet mUsesTexture;
};
} // namespace sh
#endif // COMPILER_TRANSLATOR_TEXTUREFUNCTIONHLSL_H_