src/app.cpp

   1 #include "app.hpp"
   2
   3 #include <iostream>
   4 #include <stdexcept>
   5
   6
   7 namespace {
   8
   9 constexpr GLfloat vtx_coords[] = {
  10         -1.0f, -1.0f, 0.0f,
  11          1.0f, -1.0f, 0.0f,
  12          0.0f,  1.0f, 0.0f,
  13 };
  14
  15 }
  16
  17 namespace blank {
  18
  19 Application::Application()
  20 : init_sdl()
  21 , init_img()
  22 , init_gl()
  23 , window()
  24 , ctx(window.CreateContext())
  25 , init_glew()
  26 , program()
  27 , pitch_sensitivity(-0.0025f)
  28 , yaw_sensitivity(-0.001f)
  29 , cam()
  30 , model()
  31 , vtx_buf(0)
  32 , mvp_handle(0)
  33 , running(false) {
  34         GLContext::EnableVSync();
  35         program.LoadShader(
  36                 GL_VERTEX_SHADER,
  37                 "#version 330 core\n"
  38                 "layout(location = 0) in vec3 vertexPosition_modelspace;\n"
  39                 "uniform mat4 MVP;\n"
  40                 "void main() {\n"
  41                         "vec4 v = vec4(vertexPosition_modelspace, 1);\n"
  42                         "gl_Position = MVP * v;\n"
  43                 "}\n"
  44         );
  45         program.LoadShader(
  46                 GL_FRAGMENT_SHADER,
  47                 "#version 330 core\n"
  48                 "out vec3 color;\n"
  49                 "void main() {\n"
  50                         "color = vec3(1, 1, 1);\n"
  51                 "}\n"
  52         );
  53         program.Link();
  54         if (!program.Linked()) {
  55                 program.Log(std::cerr);
  56                 throw std::runtime_error("link program");
  57         }
  58
  59         GLuint VertexArrayID;
  60         glGenVertexArrays(1, &VertexArrayID);
  61         glBindVertexArray(VertexArrayID);
  62
  63         glGenBuffers(1, &vtx_buf);
  64         glBindBuffer(GL_ARRAY_BUFFER, vtx_buf);
  65         glBufferData(GL_ARRAY_BUFFER, sizeof(vtx_coords), vtx_coords, GL_STATIC_DRAW);
  66
  67         model.Position(glm::vec3(0, 0, -4));
  68         cam.Position(glm::vec3(0, 0, 4));
  69
  70         mvp_handle = program.UniformLocation("MVP");
  71
  72         glClearColor(0.0, 0.0, 0.0, 1.0);
  73 }
  74
  75 Application::~Application() {
  76
  77 }
  78
  79
  80 void Application::Run() {
  81         running = true;
  82         Uint32 last = SDL_GetTicks();
  83         window.GrabMouse();
  84         while (running) {
  85                 Uint32 now = SDL_GetTicks();
  86                 int delta = now - last;
  87                 Loop(delta);
  88                 last = now;
  89         }
  90 }
  91
  92 void Application::Loop(int dt) {
  93         HandleEvents();
  94         Render();
  95 }
  96
  97
  98 void Application::HandleEvents() {
  99         SDL_Event event;
 100         while (SDL_PollEvent(&event)) {
 101                 switch (event.type) {
 102                         case SDL_MOUSEMOTION:
 103                                 cam.RotateYaw(event.motion.xrel * yaw_sensitivity);
 104                                 cam.RotatePitch(event.motion.yrel * pitch_sensitivity);
 105                                 std::cout << "x: " << event.motion.xrel << ", y: " << event.motion.yrel
 106                                                 << ", pitch: " << cam.Pitch() << ", yaw: " << cam.Yaw() << std::endl;
 107                                 break;
 108                         case SDL_QUIT:
 109                                 running = false;
 110                                 break;
 111                         case SDL_WINDOWEVENT:
 112                                 switch (event.window.event) {
 113                                         case SDL_WINDOWEVENT_RESIZED:
 114                                                 cam.Viewport(event.window.data1, event.window.data2);
 115                                                 break;
 116                                         default:
 117                                                 break;
 118                                 }
 119                                 break;
 120                         default:
 121                                 break;
 122                 }
 123         }
 124 }
 125
 126 void Application::Render() {
 127         glClear(GL_COLOR_BUFFER_BIT);
 128
 129         program.Use();
 130
 131         glm::mat4 mvp(cam.MakeMVP(model.Transform()));
 132         glUniformMatrix4fv(mvp_handle, 1, GL_FALSE, &mvp[0][0]);
 133
 134         glEnableVertexAttribArray(0);
 135         glBindBuffer(GL_ARRAY_BUFFER, vtx_buf);
 136         glVertexAttribPointer(
 137                 0,        // attribute 0 (for shader)
 138                 3,        // size
 139                 GL_FLOAT, // type
 140                 GL_FALSE, // normalized
 141                 0,        // stride
 142                 nullptr   // offset
 143         );
 144         glDrawArrays(
 145                 GL_TRIANGLES, // how
 146                 0,            // start
 147                 3             // len
 148         );
 149         glDisableVertexAttribArray(0);
 150
 151         window.Flip();
 152 }
 153
 154 }