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-rw-r--r--CMakeLists.txt6
-rw-r--r--src/main.cc (renamed from main.cc)93
2 files changed, 54 insertions, 45 deletions
diff --git a/CMakeLists.txt b/CMakeLists.txt
index a16dced..4a89f50 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,12 +7,12 @@ set(
)
add_executable(
- shader
- main.cc
+ computicle
+ src/main.cc
)
target_link_libraries(
- shader
+ computicle
GL
GLEW
glfw
diff --git a/main.cc b/src/main.cc
index 870006e..a307ae3 100644
--- a/main.cc
+++ b/src/main.cc
@@ -7,8 +7,7 @@
#include <vector>
#include <iostream>
#include <random>
-
-GLFWwindow* window;
+#include <chrono>
GLint getUniform(GLuint program, const std::string& name) {
const GLint uniform = glGetUniformLocation(program, name.c_str());
@@ -19,9 +18,9 @@ GLint getUniform(GLuint program, const std::string& name) {
}
GLint compileShader(const std::string& source, GLenum type) {
- GLint local_shader = glCreateShader(type);
+ GLint shader = glCreateShader(type);
- if ( !local_shader ) {
+ if ( !shader ) {
std::cerr << "Cannot create a shader of type " << type << std::endl;
exit(-1);
}
@@ -29,24 +28,24 @@ GLint compileShader(const std::string& source, GLenum type) {
const char* source_data = source.c_str();
const int source_length = source.size();
- glShaderSource(local_shader, 1, &source_data, &source_length);
- glCompileShader(local_shader);
+ glShaderSource(shader, 1, &source_data, &source_length);
+ glCompileShader(shader);
GLint compiled;
- glGetShaderiv(local_shader, GL_COMPILE_STATUS, &compiled);
+ glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
if ( !compiled ) {
std::cerr << "Cannot compile shader" << std::endl;
GLint maxLength = 0;
- glGetShaderiv(local_shader, GL_INFO_LOG_LENGTH, &maxLength);
+ glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &maxLength);
std::vector<GLchar> errorLog(maxLength);
- glGetShaderInfoLog(local_shader, maxLength, &maxLength, &errorLog[0]);
+ glGetShaderInfoLog(shader, maxLength, &maxLength, &errorLog[0]);
for( auto c : errorLog ) {
std::cerr << c;
}
std::cerr << std::endl;
}
- return local_shader;
+ return shader;
}
GLint setupShader() {
@@ -149,18 +148,36 @@ void cursor_pos_callback(GLFWwindow*, double x, double y) {
mouse_y = world_height/2 - world_height * (y / window_height);
}
+std::vector<GLfloat> makeInitialParticles(std::size_t count) {
+ std::vector<GLfloat> buffer;
+ buffer.reserve(3*count);
+
+ std::random_device rd;
+ std::mt19937 gen(rd());
+ std::uniform_real_distribution<GLfloat> distX(-world_width/2., world_width/2.);
+ std::uniform_real_distribution<GLfloat> distY(-world_height/2., world_height/2.);
+ std::uniform_real_distribution<GLfloat> distAge(0., 5.);
+
+ for ( std::size_t i = 0; i < count; ++i ) {
+ buffer.emplace_back(distX(gen));
+ buffer.emplace_back(distY(gen));
+ buffer.emplace_back(distAge(gen));
+ }
+
+ return buffer;
+}
+
int main() {
if( !glfwInit() ) {
std::cerr << "Failed to initialize GLFW" << std::endl;
return -1;
}
- glfwWindowHint(GLFW_SAMPLES, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
- window = glfwCreateWindow(window_width, window_height, "shader", NULL, NULL);
+ GLFWwindow* const window = glfwCreateWindow(window_width, window_height, "computicle", NULL, NULL);
if( window == NULL ){
std::cerr << "Failed to open GLFW window." << std::endl;
glfwTerminate();
@@ -170,7 +187,6 @@ int main() {
glfwSetCursorPosCallback(window, cursor_pos_callback);
glfwMakeContextCurrent(window);
- glewExperimental = true;
if ( glewInit() != GLEW_OK ) {
std::cerr << "Failed to initialize GLEW" << std::endl;
glfwTerminate();
@@ -185,47 +201,40 @@ int main() {
glGenVertexArrays(1, &VertexArrayID);
glBindVertexArray(VertexArrayID);
- GLint ProgramID = setupShader();
- GLuint MatrixID = glGetUniformLocation(ProgramID, "MVP");
- GLuint MouseID = glGetUniformLocation(ProgramID, "mouse");
+ GLint ShaderID = setupShader();
+ GLuint MatrixID = glGetUniformLocation(ShaderID, "MVP");
+ GLuint MouseID = glGetUniformLocation(ShaderID, "mouse");
- GLint ComputeProgramID = setupComputeShader();
- GLuint WorldID = glGetUniformLocation(ComputeProgramID, "world");
+ GLint ComputeShaderID = setupComputeShader();
+ GLuint WorldID = glGetUniformLocation(ComputeShaderID, "world");
updateMVP();
- const std::size_t particle_count = 100000;
+ const std::size_t particle_count = 500000;
- std::vector<GLfloat> vertex_buffer_data;
- vertex_buffer_data.reserve(3*particle_count);
-
- std::random_device rd;
- std::mt19937 gen(rd());
- std::uniform_real_distribution<GLfloat> distX(-world_width/2.f, world_width/2.f);
- std::uniform_real_distribution<GLfloat> distY(-world_height/2.f, world_height/2.f);
- std::uniform_real_distribution<GLfloat> distAge(0.f, 5.f);
-
- for ( int i = 0; i < particle_count; ++i ) {
- vertex_buffer_data.emplace_back(distX(gen));
- vertex_buffer_data.emplace_back(distY(gen));
- vertex_buffer_data.emplace_back(distAge(gen));
- }
+ auto vertex_buffer_data = makeInitialParticles(particle_count);
GLuint vertexbuffer;
glGenBuffers(1, &vertexbuffer);
glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
- glBufferData(GL_ARRAY_BUFFER,
- vertex_buffer_data.size() * sizeof(GLfloat), &vertex_buffer_data[0], GL_STATIC_DRAW);
+ glBufferData(GL_ARRAY_BUFFER, vertex_buffer_data.size() * sizeof(GLfloat), &vertex_buffer_data[0], GL_STATIC_DRAW);
+
+ auto lastFrame = std::chrono::high_resolution_clock::now();
do {
- glUseProgram(ComputeProgramID);
- glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, vertexbuffer);
- glUniform2f(WorldID, world_width, world_height);
- glDispatchCompute(particle_count, 1, 1);
+ // update particles at most 50 times per second
+ if ( std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::high_resolution_clock::now() - lastFrame).count() >= 20 ) {
+ glUseProgram(ComputeShaderID);
+ glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, vertexbuffer);
+ glUniform2f(WorldID, world_width, world_height);
+ glDispatchCompute(particle_count, 1, 1);
+
+ lastFrame = std::chrono::high_resolution_clock::now();
+ }
glClear(GL_COLOR_BUFFER_BIT);
- glUseProgram(ProgramID);
+ glUseProgram(ShaderID);
glUniformMatrix4fv(MatrixID, 1, GL_FALSE, &MVP[0][0]);
glUniform2f(MouseID, mouse_x, mouse_y);
@@ -246,8 +255,8 @@ int main() {
glDeleteBuffers(1, &vertexbuffer);
glDeleteVertexArrays(1, &VertexArrayID);
- glDeleteProgram(ProgramID);
- glDeleteProgram(ComputeProgramID);
+ glDeleteProgram(ShaderID);
+ glDeleteProgram(ComputeShaderID);
glfwTerminate();