commit b66d918af80940674ef4a0180f8480d1dc8876c4 Author: Gwendolyn Date: Wed May 3 17:30:39 2023 +0200 got SSBO working diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..9869d33 --- /dev/null +++ b/.gitignore @@ -0,0 +1,2 @@ +/.idea +/cmake-* diff --git a/CMakeLists.txt b/CMakeLists.txt new file mode 100644 index 0000000..c49f8da --- /dev/null +++ b/CMakeLists.txt @@ -0,0 +1,11 @@ +cmake_minimum_required(VERSION 3.24) +project(shader-automaton) + +find_package(OpenGL REQUIRED) +find_package(GLEW REQUIRED) +find_package(glfw3 3.3 REQUIRED) + + + +add_executable(shader-automaton main.cpp) +target_link_libraries(shader-automaton PRIVATE OpenGL::GL GLEW::GLEW glfw) \ No newline at end of file diff --git a/main b/main new file mode 100755 index 0000000..d582675 Binary files /dev/null and b/main differ diff --git a/main.cpp b/main.cpp new file mode 100644 index 0000000..d3a98af --- /dev/null +++ b/main.cpp @@ -0,0 +1,162 @@ +#include + +#include +#include +#include +#include +#include + +GLuint loadShader(const char *source, GLenum shader_type) { + GLuint shaderId = glCreateShader(shader_type); + GLint result = GL_FALSE; + int infoLogLength; + // Compile Vertex Shader + glShaderSource(shaderId, 1, &source, nullptr); + glCompileShader(shaderId); + glGetShaderiv(shaderId, GL_COMPILE_STATUS, &result); + glGetShaderiv(shaderId, GL_INFO_LOG_LENGTH, &infoLogLength); + if (infoLogLength > 0) { + std::vector VertexShaderErrorMessage(infoLogLength + 1); + glGetShaderInfoLog(shaderId, infoLogLength, nullptr, + &VertexShaderErrorMessage[0]); + printf("%s\n", &VertexShaderErrorMessage[0]); + exit(-1); + } + return shaderId; +} + +GLuint loadProgram(const std::vector &shaders) { + GLuint programId = glCreateProgram(); + for (const auto &item : shaders) { + glAttachShader(programId, item); + } + glLinkProgram(programId); + + GLint result = GL_FALSE; + int infoLogLength; + + glGetProgramiv(programId, GL_LINK_STATUS, &result); + glGetProgramiv(programId, GL_INFO_LOG_LENGTH, &infoLogLength); + if (infoLogLength > 0) { + std::vector ProgramErrorMessage(infoLogLength + 1); + glGetProgramInfoLog(programId, infoLogLength, nullptr, + &ProgramErrorMessage[0]); + printf("%s\n", &ProgramErrorMessage[0]); + } + return programId; +} + +static const char *vertex_shader = + "#version 460\n" + "layout(location = 0) in vec3 vertexPosition_modelspace;\n" + "out vec2 coord;\n" + "void main(){\n" + " gl_Position.xyz = vertexPosition_modelspace;\n" + " gl_Position.w = 1.0;\n" + " coord.xy = vertexPosition_modelspace.xy;\n" + "}"; + +static const char *fragment_shader = "#version 460\n" + "out vec3 color;\n" + "in vec2 coord;\n" + "layout (std430, binding = 2) restrict readonly buffer shader_data\n" + "{\n" + " int c[];\n" + "};\n" + + "void main(){\n" + " int x = int(255. * (coord.x + 1.) / 2.);" + " color = vec3(c[x]/255., 0.5,0.5);\n" + "}"; + +int main() { + glewExperimental = true; + if (!glfwInit()) { + fprintf(stderr, "Failed to initialize GLFW\n"); + return -1; + } + + glfwWindowHint(GLFW_SAMPLES, 0); + glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4); + glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 6); + glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); + glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); + + GLFWwindow *window = + glfwCreateWindow(1024, 768, "Tutorial 01", nullptr, nullptr); + if (window == nullptr) { + fprintf(stderr, + "Failed to open GLFW window. If you have an Intel GPU, they are " + "not 3.3 compatible. Try the 2.1 version of the tutorials.\n"); + glfwTerminate(); + return -1; + } + glfwMakeContextCurrent(window); // Initialize GLEW + glewExperimental = true; // Needed in core profile + if (glewInit() != GLEW_OK) { + fprintf(stderr, "Failed to initialize GLEW\n"); + return -1; + } + + glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE); + + GLuint VertexArrayID; + glGenVertexArrays(1, &VertexArrayID); + glBindVertexArray(VertexArrayID); + const GLfloat g_vertex_buffer_data[] = { + -1.0f, -1.0f, 0.0f, 1.0f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, + }; + GLuint vertexbuffer; + glGenBuffers(1, &vertexbuffer); + glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); + glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), + g_vertex_buffer_data, GL_STATIC_DRAW); + + GLuint programId = loadProgram({ + loadShader(vertex_shader, GL_VERTEX_SHADER), + loadShader(fragment_shader, GL_FRAGMENT_SHADER), + }); + + int c[256]; + + for (size_t i = 0; i < 256; ++i) { + c[i] = i; + } + + GLuint ssbo = 0; + glGenBuffers(1, &ssbo); + glBindBuffer(GL_SHADER_STORAGE_BUFFER, ssbo); + glBufferData(GL_SHADER_STORAGE_BUFFER, sizeof(int)*256, &c,GL_DYNAMIC_COPY); + glBindBuffer(GL_SHADER_STORAGE_BUFFER, 0); + + unsigned int block_index = glGetProgramResourceIndex(programId, GL_SHADER_STORAGE_BLOCK, "shader_data"); + GLuint ssbo_binding_point_index = 2; + glBindBufferBase(GL_SHADER_STORAGE_BUFFER, ssbo_binding_point_index, ssbo); + glShaderStorageBlockBinding(programId, block_index, ssbo_binding_point_index); + + do { + glClear(GL_COLOR_BUFFER_BIT); + glUseProgram(programId); + + for (int & i : c) { + i = (i + 1) % 256; + } + + glBindBuffer(GL_SHADER_STORAGE_BUFFER, ssbo); + GLvoid *p = glMapBuffer(GL_SHADER_STORAGE_BUFFER, GL_WRITE_ONLY); + std::memcpy(p, &c, sizeof(int) * 256); + glUnmapBuffer(GL_SHADER_STORAGE_BUFFER); + + glEnableVertexAttribArray(0); + glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); + glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, nullptr); + glDrawArrays(GL_TRIANGLES, 0,3); + glDisableVertexAttribArray(0); + + glfwSwapBuffers(window); + glfwPollEvents(); + + } // Check if the ESC key was pressed or the window was closed + while (glfwGetKey(window, GLFW_KEY_ESCAPE) != GLFW_PRESS && + glfwWindowShouldClose(window) == 0); +} \ No newline at end of file