+#include "app.hpp"
+
+#include <iostream>
+#include <stdexcept>
+
+
+namespace {
+
+constexpr GLfloat vtx_coords[] = {
+ -1.0f, -1.0f, -1.0f,
+ 1.0f, -1.0f, -1.0f,
+ 0.0f, 1.0f, -1.0f,
+};
+
+}
+
+namespace blank {
+
+Application::Application()
+: init_sdl()
+, init_gl()
+, window()
+, ctx(window.CreateContext())
+, init_glew()
+, program()
+, vtx_buf(0)
+, mvp()
+, mvp_handle(0)
+, running(false) {
+ GLContext::EnableVSync();
+ program.LoadShader(
+ GL_VERTEX_SHADER,
+ "#version 330 core\n"
+ "layout(location = 0) in vec3 vertexPosition_modelspace;\n"
+ "uniform mat4 MVP;\n"
+ "void main() {\n"
+ "vec4 v = vec4(vertexPosition_modelspace, 1);\n"
+ "gl_Position = MVP * v;\n"
+ "}\n"
+ );
+ program.LoadShader(
+ GL_FRAGMENT_SHADER,
+ "#version 330 core\n"
+ "out vec3 color;\n"
+ "void main() {\n"
+ "color = vec3(1, 1, 1);\n"
+ "}\n"
+ );
+ program.Link();
+ if (!program.Linked()) {
+ program.Log(std::cerr);
+ throw std::runtime_error("link program");
+ }
+
+ GLuint VertexArrayID;
+ glGenVertexArrays(1, &VertexArrayID);
+ glBindVertexArray(VertexArrayID);
+
+ glGenBuffers(1, &vtx_buf);
+ glBindBuffer(GL_ARRAY_BUFFER, vtx_buf);
+ glBufferData(GL_ARRAY_BUFFER, sizeof(vtx_coords), vtx_coords, GL_STATIC_DRAW);
+
+ glm::mat4 projection = glm::perspective(
+ 45.0f, // FOV in degrees
+ 1.0f, // aspect ratio
+ 0.1f, // near clip
+ 100.0f // far clip
+ );
+ glm::mat4 view = glm::lookAt(
+ glm::vec3(0, 0, 0), // observer
+ glm::vec3(0, 0, -1), // target
+ glm::vec3(0, 1, 0) // up
+ );
+ glm::mat4 model(1.0f); // identity: no transformation
+ mvp = projection * view * model;
+
+ mvp_handle = program.UniformLocation("MVP");
+
+ glClearColor(0.0, 0.0, 0.0, 1.0);
+}
+
+Application::~Application() {
+
+}
+
+
+void Application::Run() {
+ running = true;
+ Uint32 last = SDL_GetTicks();
+ while (running) {
+ Uint32 now = SDL_GetTicks();
+ int delta = now - last;
+ Loop(delta);
+ last = now;
+ }
+}
+
+void Application::Loop(int dt) {
+ HandleEvents();
+ Render();
+}
+
+
+void Application::HandleEvents() {
+ SDL_Event event;
+ while (SDL_PollEvent(&event)) {
+ switch (event.type) {
+ case SDL_QUIT:
+ running = false;
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+void Application::Render() {
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ program.Use();
+
+ glUniformMatrix4fv(mvp_handle, 1, GL_FALSE, &mvp[0][0]);
+
+ glEnableVertexAttribArray(0);
+ glBindBuffer(GL_ARRAY_BUFFER, vtx_buf);
+ glVertexAttribPointer(
+ 0, // attribute 0 (for shader)
+ 3, // size
+ GL_FLOAT, // type
+ GL_FALSE, // normalized
+ 0, // stride
+ nullptr // offset
+ );
+ glDrawArrays(
+ GL_TRIANGLES, // how
+ 0, // start
+ 3 // len
+ );
+ glDisableVertexAttribArray(0);
+
+ window.Flip();
+}
+
+}