shader_utils.cpp

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Author : Olli Etuaho
Date : 2018-10-01 11:54:05
Hash : 624fbdcf
Message : Refactor CompileProgram utility Tests often need to call gl functions to set up program related state after glCreateProgram has been called but prior to glLinkProgram is called. Add a callback function to the CompileProgram utility function to fulfill this need. This reduces code duplication considerably in several tests. An alternative way to improve CompileProgram would be to split it into several different utility functions. This might be slightly easier to read, but would also be a larger refactoring and require more checks at the call site. This will make it easier to implement EXT_blend_func_extended tests, which need to bind fragment outputs to different slots. BUG=angleproject:1085 TEST=angle_end2end_tests Change-Id: I3ac8b7bdc21c6a1f14517bc7df0cf6f35abd7612 Reviewed-on: https://chromium-review.googlesource.com/1254062 Commit-Queue: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Corentin Wallez <cwallez@chromium.org>
util/shader_utils.cpp
//
// Copyright (c) 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.
//

#include "shader_utils.h"

#include <vector>
#include <iostream>
#include <fstream>

static std::string ReadFileToString(const std::string &source)
{
    std::ifstream stream(source.c_str());
    if (!stream)
    {
        std::cerr << "Failed to load shader file: " << source;
        return "";
    }

    std::string result;

    stream.seekg(0, std::ios::end);
    result.reserve(static_cast<unsigned int>(stream.tellg()));
    stream.seekg(0, std::ios::beg);

    result.assign((std::istreambuf_iterator<char>(stream)), std::istreambuf_iterator<char>());

    return result;
}

GLuint CompileShader(GLenum type, const std::string &source)
{
    GLuint shader = glCreateShader(type);

    const char *sourceArray[1] = { source.c_str() };
    glShaderSource(shader, 1, sourceArray, nullptr);
    glCompileShader(shader);

    GLint compileResult;
    glGetShaderiv(shader, GL_COMPILE_STATUS, &compileResult);

    if (compileResult == 0)
    {
        GLint infoLogLength;
        glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &infoLogLength);

        // Info log length includes the null terminator, so 1 means that the info log is an empty
        // string.
        if (infoLogLength > 1)
        {
            std::vector<GLchar> infoLog(infoLogLength);
            glGetShaderInfoLog(shader, static_cast<GLsizei>(infoLog.size()), nullptr, &infoLog[0]);
            std::cerr << "shader compilation failed: " << &infoLog[0];
        }
        else
        {
            std::cerr << "shader compilation failed. <Empty log message>";
        }

        std::cerr << std::endl;

        glDeleteShader(shader);
        shader = 0;
    }

    return shader;
}

GLuint CompileShaderFromFile(GLenum type, const std::string &sourcePath)
{
    std::string source = ReadFileToString(sourcePath);
    if (source.empty())
    {
        return 0;
    }

    return CompileShader(type, source);
}

GLuint CheckLinkStatusAndReturnProgram(GLuint program, bool outputErrorMessages)
{
    if (glGetError() != GL_NO_ERROR)
        return 0;

    GLint linkStatus;
    glGetProgramiv(program, GL_LINK_STATUS, &linkStatus);
    if (linkStatus == 0)
    {
        if (outputErrorMessages)
        {
            GLint infoLogLength;
            glGetProgramiv(program, GL_INFO_LOG_LENGTH, &infoLogLength);

            // Info log length includes the null terminator, so 1 means that the info log is an
            // empty string.
            if (infoLogLength > 1)
            {
                std::vector<GLchar> infoLog(infoLogLength);
                glGetProgramInfoLog(program, static_cast<GLsizei>(infoLog.size()), nullptr,
                                    &infoLog[0]);

                std::cerr << "program link failed: " << &infoLog[0];
            }
            else
            {
                std::cerr << "program link failed. <Empty log message>";
            }
        }

        glDeleteProgram(program);
        return 0;
    }

    return program;
}

static GLuint CompileProgramInternal(const std::string &vsSource,
                                     const std::string &gsSource,
                                     const std::string &fsSource,
                                     const std::function<void(GLuint)> &preLinkCallback)
{
    GLuint vs = CompileShader(GL_VERTEX_SHADER, vsSource);
    GLuint fs = CompileShader(GL_FRAGMENT_SHADER, fsSource);

    if (vs == 0 || fs == 0)
    {
        glDeleteShader(fs);
        glDeleteShader(vs);
        return 0;
    }

    GLuint program = glCreateProgram();

    glAttachShader(program, vs);
    glDeleteShader(vs);

    glAttachShader(program, fs);
    glDeleteShader(fs);

    GLuint gs = 0;

    if (!gsSource.empty())
    {
        gs = CompileShader(GL_GEOMETRY_SHADER_EXT, gsSource);
        if (gs == 0)
        {
            glDeleteShader(vs);
            glDeleteShader(fs);
            glDeleteProgram(program);
            return 0;
        }

        glAttachShader(program, gs);
        glDeleteShader(gs);
    }

    if (preLinkCallback)
    {
        preLinkCallback(program);
    }

    glLinkProgram(program);

    return CheckLinkStatusAndReturnProgram(program, true);
}

GLuint CompileProgramWithTransformFeedback(
    const std::string &vsSource,
    const std::string &fsSource,
    const std::vector<std::string> &transformFeedbackVaryings,
    GLenum bufferMode)
{
    auto preLink = [&](GLuint program) {
        if (transformFeedbackVaryings.size() > 0)
        {
            std::vector<const char *> constCharTFVaryings;

            for (const std::string &transformFeedbackVarying : transformFeedbackVaryings)
            {
                constCharTFVaryings.push_back(transformFeedbackVarying.c_str());
            }

            glTransformFeedbackVaryings(program,
                                        static_cast<GLsizei>(transformFeedbackVaryings.size()),
                                        &constCharTFVaryings[0], bufferMode);
        }
    };

    return CompileProgramInternal(vsSource, "", fsSource, preLink);
}

GLuint CompileProgram(const std::string &vsSource, const std::string &fsSource)
{
    return CompileProgramInternal(vsSource, "", fsSource, nullptr);
}

GLuint CompileProgram(const std::string &vsSource,
                      const std::string &fsSource,
                      const std::function<void(GLuint)> &preLinkCallback)
{
    return CompileProgramInternal(vsSource, "", fsSource, preLinkCallback);
}

GLuint CompileProgramWithGS(const std::string &vsSource,
                            const std::string &gsSource,
                            const std::string &fsSource)
{
    return CompileProgramInternal(vsSource, gsSource, fsSource, nullptr);
}

GLuint CompileProgramFromFiles(const std::string &vsPath, const std::string &fsPath)
{
    std::string vsSource = ReadFileToString(vsPath);
    std::string fsSource = ReadFileToString(fsPath);
    if (vsSource.empty() || fsSource.empty())
    {
        return 0;
    }

    return CompileProgram(vsSource, fsSource);
}

GLuint CompileComputeProgram(const std::string &csSource, bool outputErrorMessages)
{
    GLuint program = glCreateProgram();

    GLuint cs = CompileShader(GL_COMPUTE_SHADER, csSource);
    if (cs == 0)
    {
        glDeleteProgram(program);
        return 0;
    }

    glAttachShader(program, cs);

    glLinkProgram(program);

    return CheckLinkStatusAndReturnProgram(program, outputErrorMessages);
}

GLuint LoadBinaryProgramOES(const std::vector<uint8_t> &binary, GLenum binaryFormat)
{
    GLuint program = glCreateProgram();
    glProgramBinaryOES(program, binaryFormat, binary.data(), static_cast<GLint>(binary.size()));
    return CheckLinkStatusAndReturnProgram(program, true);
}

GLuint LoadBinaryProgramES3(const std::vector<uint8_t> &binary, GLenum binaryFormat)
{
    GLuint program = glCreateProgram();
    glProgramBinary(program, binaryFormat, binary.data(), static_cast<GLint>(binary.size()));
    return CheckLinkStatusAndReturnProgram(program, true);
}

bool LinkAttachedProgram(GLuint program)
{
    glLinkProgram(program);
    return (CheckLinkStatusAndReturnProgram(program, true) != 0);
}

namespace angle
{

namespace essl1_shaders
{

const char *PositionAttrib()
{
    return "a_position";
}
const char *ColorUniform()
{
    return "u_color";
}

namespace vs
{

// A shader that sets gl_Position to zero.
const char *Zero()
{
    return R"(void main()
{
    gl_Position = vec4(0);
})";
}

// A shader that sets gl_Position to attribute a_position.
const char *Simple()
{
    return R"(precision highp float;
attribute vec4 a_position;

void main()
{
    gl_Position = a_position;
})";
}

// A shader that simply passes through attribute a_position, setting it to gl_Position and varying
// v_position.
const char *Passthrough()
{
    return R"(precision highp float;
attribute vec4 a_position;
varying vec4 v_position;

void main()
{
    gl_Position = a_position;
    v_position = a_position;
})";
}

}  // namespace vs

namespace fs
{

// A shader that renders a simple checker pattern of red and green. X axis and y axis separate the
// different colors. Needs varying v_position.
const char *Checkered()
{
    return R"(precision highp float;
varying vec4 v_position;

void main()
{
    if (v_position.x * v_position.y > 0.0)
    {
        gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
    }
    else
    {
        gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
    }
})";
}

// A shader that fills with color taken from uniform named "color".
const char *UniformColor()
{
    return R"(uniform mediump vec4 u_color;
void main(void)
{
    gl_FragColor = u_color;
})";
}

// A shader that fills with 100% opaque red.
const char *Red()
{
    return R"(precision mediump float;

void main()
{
    gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
})";
}

// A shader that fills with 100% opaque green.
const char *Green()
{
    return R"(precision mediump float;

void main()
{
    gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
})";
}

// A shader that fills with 100% opaque blue.
const char *Blue()
{
    return R"(precision mediump float;

void main()
{
    gl_FragColor = vec4(0.0, 0.0, 1.0, 1.0);
})";
}

}  // namespace fs
}  // namespace essl1_shaders

namespace essl3_shaders
{

const char *PositionAttrib()
{
    return "a_position";
}

namespace vs
{

// A shader that sets gl_Position to zero.
const char *Zero()
{
    return R"(#version 300 es
void main()
{
    gl_Position = vec4(0);
})";
}

// A shader that sets gl_Position to attribute a_position.
const char *Simple()
{
    return R"(#version 300 es
in vec4 a_position;
void main()
{
    gl_Position = a_position;
})";
}

}  // namespace vs

namespace fs
{

// A shader that fills with 100% opaque red.
const char *Red()
{
    return R"(#version 300 es
precision highp float;
out vec4 my_FragColor;
void main()
{
    my_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
})";
}

}  // namespace fs
}  // namespace essl3_shaders

namespace essl31_shaders
{

const char *PositionAttrib()
{
    return "a_position";
}

namespace vs
{

// A shader that sets gl_Position to zero.
const char *Zero()
{
    return R"(#version 310 es
void main()
{
    gl_Position = vec4(0);
})";
}

// A shader that sets gl_Position to attribute a_position.
const char *Simple()
{
    return R"(#version 310 es
in vec4 a_position;
void main()
{
    gl_Position = a_position;
})";
}

// A shader that simply passes through attribute a_position, setting it to gl_Position and varying
// v_position.
const char *Passthrough()
{
    return R"(#version 310 es
in vec4 a_position;
out vec4 v_position;
void main()
{
    gl_Position = a_position;
    v_position = a_position;
})";
}

}  // namespace vs

namespace fs
{

// A shader that fills with 100% opaque red.
const char *Red()
{
    return R"(#version 310 es
precision highp float;
out vec4 my_FragColor;
void main()
{
    my_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
})";
}

}  // namespace fs
}  // namespace essl31_shaders
}  // namespace angle
kc3-lang/angle/util/shader_utils.cpp

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kc3-lang/angle /util/shader_utils.cpp
