void initOpenGl()
{
glewInit();
glEnable(GL_DEPTH_TEST);
reload_shader();
//mesh and texture for pass 1
mesh_data = LoadMesh(mesh_name);
texture_id = LoadTexture(texture_name.c_str());
//mesh for pass 2 (full screen quadrilateral)
glGenVertexArrays(1, &quad_vao);
glBindVertexArray(quad_vao);
float vertices[] = {1.0f, 1.0f, 0.0f, 1.0f, -1.0f, 0.0f, -1.0f, 1.0f, 0.0f, -1.0f, -1.0f, 0.0f};
//create vertex buffers for vertex coords
glGenBuffers(1, &quad_vbo);
glBindBuffer(GL_ARRAY_BUFFER, quad_vbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
int pos_loc = glGetAttribLocation(shader_program, "pos_attrib");
if(pos_loc >= 0)
{
glEnableVertexAttribArray(pos_loc);
glVertexAttribPointer(pos_loc, 3, GL_FLOAT, false, 0, 0);
}
//create texture to render pass 1 into
const int w = glutGet(GLUT_WINDOW_WIDTH);
const int h = glutGet(GLUT_WINDOW_HEIGHT);
glGenTextures(1, &fbo_texture);
glBindTexture(GL_TEXTURE_2D, fbo_texture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, w, h, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
glBindTexture(GL_TEXTURE_2D, 0);
//Create renderbuffer for depth.
glGenRenderbuffers(1, &rbo_id);
glBindRenderbuffer(GL_RENDERBUFFER, rbo_id);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, w, h);
//Create the framebuffer object
glGenFramebuffers(1, &fbo_id);
glBindFramebuffer(GL_FRAMEBUFFER, fbo_id);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, fbo_texture, 0);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rbo_id); // attach depth renderbuffer
check_framebuffer_status();
glBindFramebuffer(GL_FRAMEBUFFER, 0);
}
// glut callbacks need to send keyboard and mouse events to imgui
void keyboard(unsigned char key, int x, int y)
{
ImGui_ImplGlut_KeyCallback(key);
std::cout << "key : " << key << ", x: " << x << ", y: " << y << std::endl;
switch(key)
{
case 'r':
case 'R':
reload_shader();
break;
}
}
int main(int argc, char *argv[])
{
if(SDL_Init(SDL_INIT_EVERYTHING) != 0)
{
exit(1);
}
IMG_Init(IMG_INIT_PNG);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
SDL_GL_SetAttribute(SDL_GL_ACCELERATED_VISUAL, 1);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, 4);
SDL_Window *window = SDL_CreateWindow("A Game Window",
SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,
1600,
1200,
SDL_WINDOW_SHOWN | SDL_WINDOW_OPENGL);
SDL_GLContext gl_context = SDL_GL_CreateContext(window);
glewExperimental = GL_TRUE;
glewInit();
glEnable(GL_MULTISAMPLE);
glEnable(GL_DEPTH_TEST);
std::vector<Vertex> grid;
// GameState setup
GameState game = {};
game.memory_sz = MEGABYTE(512);
#ifndef _WINDOWS_
game.memory = mmap(0, game.memory_sz,
PROT_READ | PROT_WRITE,
MAP_ANON | MAP_PRIVATE,
-1, 0);
#endif
#ifdef _WINDOWS_
game.memory = VirtualAlloc(NULL,
game.memory_sz,
MEM_COMMIT | MEM_RESERVE,
PAGE_READWRITE );
#endif
game.running = true;
game.projection = glm::ortho(-400.f, 400.f, -300.f, 300.f, -500.f, 500.f);
game.camera_pos = glm::vec3(0.f, 0.8f, -1.f);
game.camera_dir = glm::vec3(0.f, 0.f, 0.f);
game.view = glm::lookAt(game.camera_pos, game.camera_dir, PY);
game.entities_sz = 512;
game.entities = (Entity *)game.memory;
for(int i = 0; i < game.entities_sz; ++i)
{
game.entity_pool_limbo.push_back(&game.entities[i]);
}
// Shader Setup
Shader shader = {};
std::string u[] = { "projection", "view", "model", "lightpos", "jupiter1D" };
create_shader(&shader,
"shaders/simple.vertex.glsl",
"shaders/simple.fragment.glsl",
u,
4);
glUseProgram(shader.id);
// Create an entity
Entity *e = GetEntity(&game);
e->position = glm::vec3(0.f, 0.f, 0.f);
e->scale = glm::vec3(250.f, 250.f, 250.f);
e->rotation = glm::vec3(0.f, 0.f, 0.f);
prefab_sphere(&e->mesh, &shader);
GLuint texture = load_image_1d("images/1d_jupiter.png");
// create a grid
Entity *e2 = GetEntity(&game);
e2->position = glm::vec3(0.f, 0.f, 0.f);
e2->scale = glm::vec3(1.f, 1.f, 1.f);
e2->rotation = glm::vec3(0.f, 0.f, 0.f);
std::vector<Vertex> verts;
float size = 100.f;
float line_dist_scale = 50.f;
for(int z = 0; z <= size; ++z)
for(int x = 0; x <= size; ++x)
{
// left to right
verts.push_back({ glm::vec3( -(size*line_dist_scale/2.f), 0.f, (z*line_dist_scale)-(size*line_dist_scale/2.f)), ZERO, WHITE, glm::vec2(0.f, 0.f) });
verts.push_back({ glm::vec3( (size*line_dist_scale/2.f), 0.f, (z*line_dist_scale)-(size*line_dist_scale/2.f)), ZERO, WHITE, glm::vec2(0.f, 0.f) });
// back to front
verts.push_back({ glm::vec3( (x*line_dist_scale)-(size*line_dist_scale/2.f), 0.f, -(size*line_dist_scale/2.f)), ZERO, WHITE, glm::vec2(0.f, 0.f) });
verts.push_back({ glm::vec3( (x*line_dist_scale)-(size*line_dist_scale/2.f), 0.f, (size*line_dist_scale/2.f)), ZERO, WHITE, glm::vec2(0.f, 0.f) });
}
// custom_mesh(&e2->mesh, &verts, GL_LINES, &shader);
SDL_Event event;
double current_ticks = SDL_GetTicks();
double previous_ticks = current_ticks;
double elapsed_ticks = 0;
while(game.running)
{
previous_ticks = current_ticks;
current_ticks = SDL_GetTicks();
elapsed_ticks = current_ticks - previous_ticks;
while(SDL_PollEvent(&event))
{
switch(event.type)
{
case SDL_KEYDOWN:
{
game.keyboard_state[event.key.keysym.sym] = true;
if(event.key.keysym.sym == SDLK_w)
{
game.camera_pos.z += 1.f;
game.camera_dir.z += 1.f;
#ifdef DEBUG_BUILD
std::cout << "Camera Position: ";
std::cout << game.camera_pos.x << ", " << game.camera_pos.y << ", " << game.camera_pos.z << std::endl;
#endif
}
if(event.key.keysym.sym == SDLK_s){
game.camera_pos.z -= 1.f;
game.camera_dir.z -= 1.f;
#ifdef DEBUG_BUILD
std::cout << "Camera Position: ";
std::cout << game.camera_pos.x << ", " << game.camera_pos.y << ", " << game.camera_pos.z << std::endl;
#endif
}
if(event.key.keysym.sym == SDLK_UP)
{
game.camera_pos.y += 0.1f;
#ifdef DEBUG_BUILD
std::cout << "Camera Position: ";
std::cout << game.camera_pos.x << ", " << game.camera_pos.y << ", " << game.camera_pos.z << std::endl;
#endif
}
if(event.key.keysym.sym == SDLK_DOWN)
{
game.camera_pos.y -= 0.1f;
#ifdef DEBUG_BUILD
std::cout << "Camera Position: ";
std::cout << game.camera_pos.x << ", " << game.camera_pos.y << ", " << game.camera_pos.z << std::endl;
#endif
}
if(event.key.keysym.sym == SDLK_RIGHT)
{
glm::vec3 look = game.camera_pos - game.camera_dir;
look = glm::rotate({ look.x, 0.f, look.z }, 6.5f, PY);
game.camera_pos = { look.x, game.camera_pos.y, look.z };
// game.camera_pos.x -= 0.1f;
#ifdef DEBUG_BUILD
std::cout << "Camera Position: ";
std::cout << game.camera_pos.x << ", " << game.camera_pos.y << ", " << game.camera_pos.z << std::endl;
#endif
}
if(event.key.keysym.sym == SDLK_LEFT)
{
glm::vec3 look = game.camera_pos - game.camera_dir;
look = glm::rotate({ look.x, 0.f, look.z }, -6.5f, PY);
game.camera_pos = { look.x, game.camera_pos.y, look.z };
#ifdef DEBUG_BUILD
std::cout << "Camera Position: ";
std::cout << game.camera_pos.x << ", " << game.camera_pos.y << ", " << game.camera_pos.z << std::endl;
#endif
}
if(event.key.keysym.sym == SDLK_l)
{
reload_shader(&shader, {}, 0);
}
if(event.key.keysym.sym == SDLK_g)
{
glPolygonMode( GL_FRONT_AND_BACK, GL_LINE );
}
if(event.key.keysym.sym == SDLK_f)
{
glPolygonMode( GL_FRONT_AND_BACK, GL_FILL );
}
break;
}
case SDL_KEYUP:
{
game.keyboard_state[event.key.keysym.sym] = false;
break;
}
case SDL_MOUSEMOTION:
{
game.mouse_pos.x = event.motion.x;
game.mouse_pos.y = event.motion.y;
break;
}
case SDL_WINDOWEVENT:
{
switch(event.window.event)
{
case SDL_WINDOWEVENT_FOCUS_GAINED:
{
break;
}
}
break;
}
case SDL_QUIT:
{
game.running = false;
break;
}
}
}
// NOTE(brett): Update code goes here
// NOTE(brett): Render code goes here
glClearColor(0.1f, 0.0f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// draw a grid in the x/z coord
game.view = glm::lookAt(game.camera_pos, game.camera_dir, PY);
glUniformMatrix4fv(shader.uniforms["projection"], 1, GL_FALSE, (GLfloat *)&game.projection[0]);
glUniformMatrix4fv(shader.uniforms["view"] , 1, GL_FALSE, (GLfloat *)&game.view[0]);
glUniform1i(shader.uniforms["jupiter1D"], 0);
glm::vec3 light = game.camera_pos-game.camera_dir;
glUniform3fv(shader.uniforms["lightpos"], 1, (GLfloat *)&light);
for(std::list<Entity *>::iterator it = game.entity_pool_alive.begin();
it != game.entity_pool_alive.end();
++it)
{
glBindVertexArray((*it)->mesh.VAO);
glm::mat4 model = glm::mat4();
model = glm::translate(model, (*it)->position);
model = glm::scale(model, (*it)->scale);
glUniformMatrix4fv(shader.uniforms["model"], 1, GL_FALSE, (GLfloat *)&model[0]);
glDrawArrays((*it)->mesh.draw_method, 0, (*it)->mesh.vertices.size());
}
glBindVertexArray(0);
SDL_GL_SwapWindow(window);
}
SDL_Quit();
return 0;
}