240 lines
8.4 KiB
C++
240 lines
8.4 KiB
C++
/* +------------------------------------------------------+
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____/ \____ /| - Open source game framework licensed to freely use, |
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\ / / | copy, modify and sell without restriction |
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+--\ ^__^ /--+ | |
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| ~/ \~ | | - created for <https://foam.shampoo.ooo> |
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| ~~~~~~~~~~~~ | +------------------------------------------------------+
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| SPACE ~~~~~ | /
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| ~~~~~~~ BOX |/
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+--------------+
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Display a rotating box with a space texture and gradient background using SDL, OpenGL, and [SPACE BOX].
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*/
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#include <iostream>
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#include <stdio.h>
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#include <math.h>
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#include <vector>
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#include <array>
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#include <list>
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#include <cstdlib>
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#include <algorithm>
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#include <string>
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#include <functional>
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#include <fstream>
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#include "glm/glm.hpp"
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#include "Game.hpp"
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#include "GLObject.hpp"
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#include "VBO.hpp"
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#include "Model.hpp"
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struct BoxDemo : Game
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{
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private:
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sb::Model box;
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sb::Plane background;
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bool right_active = false, down_active = false, left_active = false, up_active = false, is_writing_audio = true;
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SDL_Event event;
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sb::Texture fake;
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GLuint mvp_uniform_id, flat_program, world_program;
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glm::mat4 projection, view, model = glm::mat4(1.0f), mvp;
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sb::VAO vao;
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sb::VBO vbo;
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sb::Timer timer;
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public:
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BoxDemo()
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{
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Mix_Music *music = Mix_LoadMUS("resource/Field.mp3");
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Mix_PlayMusic(music, -1);
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load_gl_context();
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delegate().subscribe(&BoxDemo::respond, this);
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delegate().subscribe(&BoxDemo::respond, this, SDL_MOUSEBUTTONDOWN);
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timer.on();
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}
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void load_gl_context()
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{
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Game::load_gl_context();
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/* Generate a vertex array object ID, bind it as current (requirement of OpenGL) */
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vao.generate();
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vao.bind();
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/* Generate ID for the vertex buffer object that will hold all vertex data. Using one buffer for all attributes, data
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* will be copied in one after the other. */
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vbo.generate();
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vbo.bind();
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/*
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v0-v1-v2 (front)
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v2-v3-v0
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v0-v3-v4 (right)
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v4-v5-v0
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v0-v5-v6 (top)
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v6-v1-v0
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v1-v6-v7 (left)
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v7-v2-v1
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v7-v4-v3 (bottom)
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v3-v2-v7
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v4-v7-v6 (back)
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v6-v5-v4
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*/
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box = sb::Model({
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{"position", {
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{1, 1, 1}, {-1, 1, 1}, {-1,-1, 1},
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{-1,-1, 1}, {1,-1, 1}, {1, 1, 1},
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{1, 1, 1}, {1,-1, 1}, {1,-1,-1},
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{1,-1,-1}, {1, 1,-1}, {1, 1, 1},
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{1, 1, 1}, {1, 1,-1}, {-1, 1,-1},
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{-1, 1,-1}, {-1, 1, 1}, {1, 1, 1},
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{-1, 1, 1}, {-1, 1,-1}, {-1,-1,-1},
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{-1,-1,-1}, {-1,-1, 1}, {-1, 1, 1},
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{-1,-1,-1}, {1,-1,-1}, {1,-1, 1},
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{1,-1, 1}, {-1,-1, 1}, {-1,-1,-1},
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{1,-1,-1}, {-1,-1,-1}, {-1, 1,-1},
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{-1, 1,-1}, {1, 1,-1}, {1,-1,-1}
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}},
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{"uv", {
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{1, 1}, {0, 1}, {0, 0},
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{0, 0}, {1, 0}, {1, 1},
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{0, 1}, {0, 0}, {1, 0},
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{1, 0}, {1, 1}, {0, 1},
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{0, 1}, {0, 0}, {1, 0},
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{1, 0}, {1, 1}, {0, 1},
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{1, 1}, {0, 1}, {0, 0},
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{0, 0}, {1, 0}, {1, 1},
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{0, 0}, {1, 0}, {1, 1},
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{1, 1}, {0, 1}, {0, 0},
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{0, 0}, {1, 0}, {1, 1},
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{1, 1}, {0, 1}, {0, 0}
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}}
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});
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box.texture(sb::Texture());
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box.texture(0).load("resource/tile.png");
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/* Create a 1x1 white texture */
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glm::vec2 fake_size = {1, 1};
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unsigned char fake_color[4] = {255, 255, 255, 255};
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fake.generate(fake_size);
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fake.load(fake_color, fake_size);
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/* Add color attributes and a full white texture */
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background.attributes({
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{0.2f, 0.6f, 0.8f}, {0.2f, 0.6f, 0.8f}, {1.0f, 1.0f, 0.0f},
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{0.2f, 0.6f, 0.8f}, {1.0f, 1.0f, 0.0f}, {1.0f, 1.0f, 0.0f}
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}, "color");
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background.texture(fake);
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glEnable(GL_BLEND);
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glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
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/* Create a projection matrix */
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glm::ivec2 resolution = get_display().window_size();
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float aspect = resolution.x / (float) resolution.y;
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projection = glm::perspective(glm::radians(40.0f) / aspect, aspect, 0.1f, 100.0f);
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view = glm::lookAt(glm::vec3{4.0f, 3.0f, 3.0f}, glm::vec3{0.0f, 0.65f, 0.0f}, glm::vec3{0.0f, 1.0f, 0.0f});
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/* Load shader programs, associate model attributes with shader variables, read uniform IDs */
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GLuint triangle_vertex_shader = load_shader("shaders/triangle.vert", GL_VERTEX_SHADER);
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GLuint fragment_shader = load_shader("shaders/all.frag", GL_FRAGMENT_SHADER);
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GLuint flat_vertex_shader = load_shader("shaders/flat.vert", GL_VERTEX_SHADER);
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world_program = glCreateProgram();
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glAttachShader(world_program, triangle_vertex_shader);
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glAttachShader(world_program, fragment_shader);
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link_shader(world_program);
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box.attributes("position")->bind("in_Position", world_program);
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box.attributes("uv")->bind("vertexUV", world_program);
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flat_program = glCreateProgram();
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glAttachShader(flat_program, flat_vertex_shader);
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glAttachShader(flat_program, fragment_shader);
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link_shader(flat_program);
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background.attributes("position")->bind("in_Position", flat_program);
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background.attributes("uv")->bind("vertexUV", flat_program);
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background.attributes("color")->bind("in_Color", flat_program);
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mvp_uniform_id = glGetUniformLocation(world_program, "MVP");
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/* Fill VBO with attribute data */
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vbo.allocate(background.size() + box.size(), GL_STATIC_DRAW);
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vbo.add(*sb::Plane::position);
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vbo.add(*sb::Plane::uv);
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vbo.add(*background.attributes("color"));
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vbo.add(*box.attributes("position"));
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vbo.add(*box.attributes("uv"));
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sb::Log::gl_errors("after filling VBO");
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for (GLuint program : {flat_program, world_program})
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{
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/* Set the active texture unit to #0, Get the texture uniform from the shader and set it use texture #0. See
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* https://www.khronos.org/opengl/wiki/Sampler_(GLSL)#Binding_textures_to_samplers */
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glUseProgram(program);
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glActiveTexture(GL_TEXTURE0);
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glUniform1i(glGetUniformLocation(program, "myTextureSampler"), 0);
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}
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glDepthFunc(GL_LESS);
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}
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void respond(SDL_Event& event)
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{
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if (delegate().compare(event, "play-sound") || event.type == SDL_MOUSEBUTTONDOWN)
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{
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Mix_Chunk* music = Mix_LoadWAV("resource/Ag.ogg");
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Mix_PlayChannel(-1, music, 0);
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}
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}
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void update(float timestamp)
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{
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glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
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glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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glDisable(GL_DEPTH_TEST);
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/* Keep timer up to date */
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timer.update(timestamp);
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/* Draw background */
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glUseProgram(flat_program);
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box.disable();
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background.bind();
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background.enable();
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glDrawArrays(GL_TRIANGLES, 0, background.attributes("position")->count());
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/* Rotate projection matrix */
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model = glm::rotate(model, timer.delta(0.25f), glm::vec3(0.0f, 1.0f, 0.0f));
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mvp = projection * view * model;
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glUseProgram(world_program);
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/* Pass the MVP matrix to the triangle vertex shader using the memory address of the top left value */
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glUniformMatrix4fv(mvp_uniform_id, 1, GL_FALSE, &mvp[0][0]);
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/* Set the color attribute to white so the texture will not be modified */
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glVertexAttrib3f(glGetAttribLocation(world_program, "in_Color"), 1, 1, 1);
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/* Draw the box */
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glEnable(GL_DEPTH_TEST);
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background.disable();
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box.bind();
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box.enable();
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glDrawArrays(GL_TRIANGLES, 0, box.attributes("position")->count());
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SDL_GL_SwapWindow(window());
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}
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};
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int main()
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{
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BoxDemo demo = BoxDemo();
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demo.run();
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demo.quit();
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return 0;
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}
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