Persson-dev/OpenGLComputeShader
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This commit is contained in:
TheCherno
2025-02-26 20:23:26 +11:00
parent 30710362ed
commit 9e6f7d5e8d
10 changed files with 414 additions and 2 deletions
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4
.gitignore vendored
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@@ -10,3 +10,7 @@ compile_commands.json
CTestTestfile.cmake CTestTestfile.cmake
_deps _deps
CMakeUserPresets.json CMakeUserPresets.json
# Visual Studio
.vs/
*.user

18
App/CMakeLists.txt Normal file
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# App
set(SOURCE_DIR "Source")
set(SOURCES
Source/Main.cpp
Source/Shader.h
Source/Shader.cpp
Source/Renderer.h
Source/Renderer.cpp
)
# Add the executable target
add_executable(App ${SOURCES})
target_link_libraries(App glfw)
target_link_libraries(App glad)
target_link_libraries(App glm)

32
App/Shaders/Compute.glsl Normal file
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#version 460 core
layout(rgba32f, binding = 0) uniform writeonly image2D outputImage;
layout(local_size_x = 16, local_size_y = 16) in;
void main()
{
ivec2 pixelCoord = ivec2(gl_GlobalInvocationID.xy);
if (pixelCoord.x >= imageSize(outputImage).x || pixelCoord.y >= imageSize(outputImage).y)
return;
ivec2 texSize = imageSize(outputImage);
vec2 fTexSize = vec2(texSize);
vec2 normalizedCoord = vec2(pixelCoord) / vec2(texSize);
vec4 O = vec4(0, 0, 0, 1);
vec2 I = vec2(pixelCoord);
float iTime = 2.2;
float i = 0.0, t=iTime;
O *= i;
for(vec2 a=fTexSize.xy, p=(I+I-a)/a.y; i++<20.;
O += (cos(sin(i*.2+t)*vec4(0,4,3,1))+2.)
/(i/1e3+abs(length(a-.5*min(a+a.yx,.1))-.05)))
a.x = abs(a = (fract(.2*t+.3*p*i*mat2(cos(cos(.2*t+.2*i)+vec4(0,11,33,0))))-.5)).x;
O = tanh(O*O/2e5);
vec4 color = vec4(normalizedCoord, 0.0, 1.0);
imageStore(outputImage, pixelCoord, O);
}

102
App/Source/Main.cpp Normal file
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#include <iostream>
#include <glm/glm.hpp>
#include "Shader.h"
#include "Renderer.h"
static uint32_t s_ComputeShader = -1;
static const std::filesystem::path s_ComputeShaderPath = "Shaders/Compute.glsl";
static void ErrorCallback(int error, const char* description)
{
std::cerr << "Error: " << description << std::endl;
}
static void KeyCallback(GLFWwindow* window, int key, int scancode, int action, int mods)
{
if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
glfwSetWindowShouldClose(window, GLFW_TRUE);
if (key == GLFW_KEY_R)
s_ComputeShader = ReloadComputeShader(s_ComputeShader, s_ComputeShaderPath);
}
int main()
{
glfwSetErrorCallback(ErrorCallback);
if (!glfwInit())
exit(EXIT_FAILURE);
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 6);
int width = 1280;
int height = 720;
GLFWwindow* window = glfwCreateWindow(width, height, "Compute", NULL, NULL);
if (!window)
{
glfwTerminate();
exit(EXIT_FAILURE);
}
glfwSetKeyCallback(window, KeyCallback);
glfwMakeContextCurrent(window);
gladLoadGL(glfwGetProcAddress);
glfwSwapInterval(1);
s_ComputeShader = CreateComputeShader(s_ComputeShaderPath);
if (s_ComputeShader == -1)
{
std::cerr << "Compute shader failed\n";
return -1;
}
Texture computeShaderTexture = CreateTexture(width, height);
Framebuffer fb = CreateFramebufferWithTexture(computeShaderTexture);
while (!glfwWindowShouldClose(window))
{
glfwGetFramebufferSize(window, &width, &height);
// Resize texture
if (width != computeShaderTexture.Width || height != computeShaderTexture.Height)
{
glDeleteTextures(1, &computeShaderTexture.Handle);
computeShaderTexture = CreateTexture(width, height);
AttachTextureToFramebuffer(fb, computeShaderTexture);
}
// Compute
{
glUseProgram(s_ComputeShader);
glBindImageTexture(0, fb.ColorAttachment.Handle, 0, GL_FALSE, 0, GL_WRITE_ONLY, GL_RGBA32F);
const GLuint workGroupSizeX = 16;
const GLuint workGroupSizeY = 16;
GLuint numGroupsX = (width + workGroupSizeX - 1) / workGroupSizeX;
GLuint numGroupsY = (height + workGroupSizeY - 1) / workGroupSizeY;
glDispatchCompute(numGroupsX, numGroupsY, 1);
// Ensure all writes to the image are complete
glMemoryBarrier(GL_SHADER_IMAGE_ACCESS_BARRIER_BIT);
}
// Blit
{
BlitFramebufferToSwapchain(fb);
}
glfwSwapBuffers(window);
glfwPollEvents();
}
glfwDestroyWindow(window);
glfwTerminate();
}

61
App/Source/Renderer.cpp Normal file
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#include "Renderer.h"
#include <iostream>
Texture CreateTexture(int width, int height)
{
Texture result;
result.Width = width;
result.Height = height;
glCreateTextures(GL_TEXTURE_2D, 1, &result.Handle);
glTextureStorage2D(result.Handle, 1, GL_RGBA32F, width, height);
glTextureParameteri(result.Handle, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTextureParameteri(result.Handle, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTextureParameteri(result.Handle, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTextureParameteri(result.Handle, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
return result;
}
Framebuffer CreateFramebufferWithTexture(const Texture texture)
{
Framebuffer result;
glCreateFramebuffers(1, &result.Handle);
if (!AttachTextureToFramebuffer(result, texture))
{
glDeleteFramebuffers(1, &result.Handle);
return {};
}
return result;
}
bool AttachTextureToFramebuffer(Framebuffer& framebuffer, const Texture texture)
{
glNamedFramebufferTexture(framebuffer.Handle, GL_COLOR_ATTACHMENT0, texture.Handle, 0);
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
{
std::cerr << "Framebuffer is not complete!" << std::endl;
return false;
}
framebuffer.ColorAttachment = texture;
return true;
}
void BlitFramebufferToSwapchain(const Framebuffer framebuffer)
{
glBindFramebuffer(GL_READ_FRAMEBUFFER, framebuffer.Handle);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0); // swapchain
glBlitFramebuffer(0, 0, framebuffer.ColorAttachment.Width, framebuffer.ColorAttachment.Height, // Source rect
0, 0, framebuffer.ColorAttachment.Width, framebuffer.ColorAttachment.Height, // Destination rect
GL_COLOR_BUFFER_BIT, GL_NEAREST);
}

23
App/Source/Renderer.h Normal file
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#pragma once
#include <glad/gl.h>
#define GLFW_INCLUDE_NONE
#include <GLFW/glfw3.h>
struct Texture
{
GLuint Handle = 0;
uint32_t Width = 0;
uint32_t Height = 0;
};
struct Framebuffer
{
GLuint Handle = 0;
Texture ColorAttachment;
};
Texture CreateTexture(int width, int height);
Framebuffer CreateFramebufferWithTexture(const Texture texture);
bool AttachTextureToFramebuffer(Framebuffer& framebuffer, const Texture texture);
void BlitFramebufferToSwapchain(const Framebuffer framebuffer);

81
App/Source/Shader.cpp Normal file
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#include "Shader.h"
#include <iostream>
#include <fstream>
#include <glad/gl.h>
uint32_t CreateComputeShader(const std::filesystem::path& path)
{
std::ifstream file(path);
if (!file.is_open())
{
std::cerr << "Failed to open file: " << path.string() << std::endl;
return -1;
}
std::ostringstream contentStream;
contentStream << file.rdbuf();
std::string shaderSource = contentStream.str();
GLuint shaderHandle = glCreateShader(GL_COMPUTE_SHADER);
const GLchar* source = (const GLchar*)shaderSource.c_str();
glShaderSource(shaderHandle, 1, &source, 0);
glCompileShader(shaderHandle);
GLint isCompiled = 0;
glGetShaderiv(shaderHandle, GL_COMPILE_STATUS, &isCompiled);
if (isCompiled == GL_FALSE)
{
GLint maxLength = 0;
glGetShaderiv(shaderHandle, GL_INFO_LOG_LENGTH, &maxLength);
std::vector<GLchar> infoLog(maxLength);
glGetShaderInfoLog(shaderHandle, maxLength, &maxLength, &infoLog[0]);
std::cerr << infoLog.data() << std::endl;
glDeleteShader(shaderHandle);
return -1;
}
GLuint program = glCreateProgram();
glAttachShader(program, shaderHandle);
glLinkProgram(program);
GLint isLinked = 0;
glGetProgramiv(program, GL_LINK_STATUS, (int*)&isLinked);
if (isLinked == GL_FALSE)
{
GLint maxLength = 0;
glGetProgramiv(program, GL_INFO_LOG_LENGTH, &maxLength);
std::vector<GLchar> infoLog(maxLength);
glGetProgramInfoLog(program, maxLength, &maxLength, &infoLog[0]);
std::cerr << infoLog.data() << std::endl;
glDeleteProgram(program);
glDeleteShader(shaderHandle);
return -1;
}
glDetachShader(program, shaderHandle);
return program;
}
uint32_t ReloadComputeShader(uint32_t shaderHandle, const std::filesystem::path& path)
{
uint32_t newShaderHandle = CreateComputeShader(path);
// Return old shader if compilation failed
if (newShaderHandle == -1)
return shaderHandle;
glDeleteProgram(shaderHandle);
return newShaderHandle;
}

6
App/Source/Shader.h Normal file
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@@ -0,0 +1,6 @@
#pragma once
#include <filesystem>
uint32_t CreateComputeShader(const std::filesystem::path& path);
uint32_t ReloadComputeShader(uint32_t shaderHandle, const std::filesystem::path& path);

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CMakeLists.txt Normal file
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cmake_minimum_required(VERSION 3.28)
include(FetchContent)
project(App)
set(CMAKE_CXX_STANDARD 20)
#
# Dependencies
#
# GLFW
find_package(glfw3 3.4 QUIET)
if (NOT glfw3_FOUND)
FetchContent_Declare(
glfw3
DOWNLOAD_EXTRACT_TIMESTAMP OFF
URL https://github.com/glfw/glfw/releases/download/3.4/glfw-3.4.zip
)
FetchContent_GetProperties(glfw3)
if (NOT glfw3_POPULATED)
set(FETCHCONTENT_QUIET NO)
FetchContent_Populate(glfw3)
add_subdirectory(${glfw3_SOURCE_DIR} ${glfw3_BINARY_DIR})
endif()
endif()
# OpenGL
find_package(OpenGL REQUIRED)
# GLAD
FetchContent_Declare(
glad
DOWNLOAD_EXTRACT_TIMESTAMP OFF
URL https://github.com/Dav1dde/glad/archive/refs/tags/v2.0.8.zip
)
FetchContent_GetProperties(glad)
if(NOT glad_POPULATED)
set(FETCHCONTENT_QUIET NO)
FetchContent_MakeAvailable(glad)
add_subdirectory("${glad_SOURCE_DIR}/cmake" glad_cmake)
glad_add_library(glad REPRODUCIBLE EXCLUDE_FROM_ALL LOADER API gl:core=4.6)
endif()
set_target_properties(glad PROPERTIES FOLDER "Dependencies")
# GLM
find_package(glm 1.0.1 QUIET)
if (NOT glm_FOUND)
FetchContent_Declare(
glm
DOWNLOAD_EXTRACT_TIMESTAMP OFF
URL https://github.com/g-truc/glm/archive/refs/tags/1.0.1.zip
)
FetchContent_GetProperties(glm)
if (NOT glm_POPULATED)
set(FETCHCONTENT_QUIET NO)
FetchContent_Populate(glm)
add_subdirectory(${glm_SOURCE_DIR} ${glm_BINARY_DIR})
endif()
endif()
set_target_properties(glm PROPERTIES FOLDER "Dependencies")
#
# Projects
#
add_subdirectory(App)

18
README.md
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@@ -1,2 +1,18 @@
# GPU Compute # GPU Compute
Simple app to run compute shaders using OpenGL Simple app to run compute shaders using OpenGL.
## Building
Just run CMake and build. Here's an example:
```
mkdir build
cd build
cmake ..
```
Tested on Windows 11 using Visual Studio 2022, more testing to follow.
## Third-Party Dependencies
Uses the following third-party dependencies:
- [GLFW 3.4](https://github.com/glfw/glfw)
- [Glad](https://github.com/Dav1dde/glad)
- [glm](https://github.com/g-truc/glm)