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#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <Helpers.h>
#include <iostream>
#include <vector>
void error_callback(int error, const char* description)
{
std::cerr << "Error: " << description << std::endl;
}
int main(int argc, char * argv[])
{
Helpers::RenderSettings settings;
if(!settings.ParseCommandLine(argc,argv))
{
return 2;
}
unsigned int bufferHeight = settings.imageHeight/2;
GLFWwindow* window;
/* Initialize the library */
if (!glfwInit())
return -1;
glfwSetErrorCallback(error_callback);
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
/* Create a windowed mode window and its OpenGL context */
window = glfwCreateWindow(settings.windowWidth, settings.windowHeight, "Buddhabrot", NULL, NULL);
if (!window)
{
std::cerr << "Failed to create OpenGL 4.3 core context. We do not support compatibility contexts." << std::endl;
glfwTerminate();
return -1;
}
/* Make the window's context current */
glfwMakeContextCurrent(window);
gladLoadGLLoader((GLADloadproc)glfwGetProcAddress);
//we have a context. Let's check if input is sane.
//calcualte buffer size, and make sure it's allowed by the driver.
const unsigned int pixelCount{(settings.imageWidth * bufferHeight)*3}; //*3 -> RGB
if(!settings.CheckValidity())
{
glfwTerminate();
return 1;
}
// Create and compile our GLSL program from the shaders
std::string vertexPath("Shaders/BuddhaVertex.glsl");
std::string fragmentPath("Shaders/BuddhaFragment.glsl");
std::string computePath("Shaders/BuddhaCompute.glsl");
if(!Helpers::DoesFileExist(vertexPath))
{
#if defined _WIN32 || defined __CYGWIN__
std::string separator("\\");
#else
std::string separator("/");
#endif
vertexPath = INSTALL_PREFIX + separator + "share" + separator + "BuddhaShader" + separator + vertexPath;
fragmentPath = INSTALL_PREFIX + separator + "share" + separator + "BuddhaShader" + separator + fragmentPath;
computePath = INSTALL_PREFIX + separator + "share" + separator + "BuddhaShader" + separator + computePath;
}
GLuint VertexAndFragmentShaders = Helpers::LoadShaders(vertexPath, fragmentPath);
//Do the same for the compute shader:
GLuint ComputeShader = Helpers::LoadComputeShader(computePath, settings.localWorkgroupSizeX, settings.localWorkgroupSizeY, settings.localWorkgroupSizeZ);
if(VertexAndFragmentShaders == 0 || ComputeShader == 0)
{
std::cout << "Something went wrong with loading the shaders. Abort." << std::endl;
glfwTerminate();
return 1;
}
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,
-1.0f, 1.0f, 0.0f,
1.0f, 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 drawBuffer;
glGenBuffers(1, &drawBuffer);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, drawBuffer);
{
glBufferData(GL_SHADER_STORAGE_BUFFER, 4 * pixelCount, nullptr, GL_DYNAMIC_COPY);
glClearBufferData(GL_SHADER_STORAGE_BUFFER,GL_R8,GL_RED,GL_UNSIGNED_INT,nullptr);
}
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 2, drawBuffer);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, 0);
uint32_t iterationCount{0};
glUseProgram(ComputeShader);
GLint iterationCountUniformHandle = glGetUniformLocation(ComputeShader, "iterationCount");
GLint orbitLengthUniformHandle = glGetUniformLocation(ComputeShader, "orbitLength");
GLint widthUniformComputeHandle = glGetUniformLocation(ComputeShader, "width");
GLint heightUniformComputeHandle = glGetUniformLocation(ComputeShader, "height");
glUniform3ui(orbitLengthUniformHandle,settings.orbitLengthRed,settings.orbitLengthGreen,settings.orbitLengthBlue);
glUniform1ui(widthUniformComputeHandle, settings.imageWidth);
glUniform1ui(heightUniformComputeHandle, bufferHeight);
glUseProgram(VertexAndFragmentShaders);
GLint widthUniformFragmentHandle = glGetUniformLocation(VertexAndFragmentShaders, "width");
GLint heightUniformFragmentHandle = glGetUniformLocation(VertexAndFragmentShaders, "height");
glUniform1ui(widthUniformFragmentHandle, settings.imageWidth);
glUniform1ui(heightUniformFragmentHandle, bufferHeight);
glClearColor(0.0f, 0.0f, 0.4f, 0.0f);
//uint32_t iterationsPerFrame = settings.globalWorkGroupSizeX*settings.globalWorkGroupSizeY*settings.globalWorkGroupSizeZ*settings.localWorkgroupSizeX*settings.localWorkgroupSizeY*settings.localWorkgroupSizeZ;
//bool bWarningShown{false};
/* Loop until the user closes the window */
while (!glfwWindowShouldClose(window))
{
//commented out, as with the new y-decoupling we will get more points in 2D even after we had all integer values for x.
//check if we are "done"
//if(iterationsPerFrame * iterationCount <= iterationsPerFrame && iterationCount > 1 && !bWarningShown)
//{
// std::cout << "The program covered all possible integer values for starting point computation. Leaving it running will not improve the image any more." << std::endl;
// bWarningShown = true;
//}
//let the compute shader do something
glUseProgram(ComputeShader);
//increase iterationCount, which is used for pseudo random generation
glUniform1ui(iterationCountUniformHandle,++iterationCount);
glDispatchCompute(settings.globalWorkGroupSizeX, settings.globalWorkGroupSizeY, settings.globalWorkGroupSizeZ);
//before reading the values in the ssbo, we need a memory barrier:
glMemoryBarrier(GL_SHADER_STORAGE_BARRIER_BIT); //I hope this is the correct (and only required) bit
/* Render here */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glUseProgram(VertexAndFragmentShaders);
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
glVertexAttribPointer(
0, // attribute 0. No particular reason for 0, but must match the layout in the shader.
3, // size
GL_FLOAT, // type
GL_FALSE, // normalized?
0, // stride
(void*)0 // array buffer offset
);
// Draw the triangle strip!
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); // Triangle strip with 4 vertices -> quad.
glDisableVertexAttribArray(0);
/* Swap front and back buffers */
glfwSwapBuffers(window);
/* Poll for and process events */
glfwPollEvents();
}
if(!settings.pngFilename.empty())
{
glMemoryBarrier(GL_ALL_BARRIER_BITS);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, drawBuffer);
{
std::vector<uint32_t> readBackBuffer(pixelCount);
glGetBufferSubData(GL_SHADER_STORAGE_BUFFER,0,4 * pixelCount,readBackBuffer.data());
Helpers::WriteOutputPNG(settings.pngFilename,readBackBuffer,settings.imageWidth,bufferHeight, settings.pngGamma, settings.pngColorScale);
}
}
//a bit of cleanup
glDeleteBuffers(1,&vertexbuffer);
glDeleteBuffers(1,&drawBuffer);
glfwTerminate();
return 0;
}
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