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#include <iostream>
#include <stdlib.h>
#ifdef __APPLE__
# include <OpenGL/OpenGL.h>
# include <GLUT/glut.h>
#else
# include <GL/glut.h>
#endif
#include "../easylogging++.h"
#include "imageloader.h"
INITIALIZE_EASYLOGGINGPP
using namespace std;
const float BOX_SIZE = 7.0f; //The length of each side of the cube
float _angle = 0; //The rotation of the box
GLuint _textureId; //The OpenGL id of the texture
void handleKeypress(unsigned char key, int x, int y) {
switch (key) {
case 27: //Escape key
exit(0);
}
}
//Makes the image into a texture, and returns the id of the texture
GLuint loadTexture(Image* image) {
VLOG(1) << "Loading texture from image...";
GLuint textureId;
glGenTextures(1, &textureId);
glBindTexture(GL_TEXTURE_2D, textureId);
glTexImage2D(GL_TEXTURE_2D,
0,
GL_RGB,
image->width, image->height,
0,
GL_RGB,
GL_UNSIGNED_BYTE,
image->pixels);
return textureId;
}
void initRendering() {
VLOG(1) << "Initializing rendering";
glEnable(GL_DEPTH_TEST);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_NORMALIZE);
glEnable(GL_COLOR_MATERIAL);
Image* image = loadBMP("vtr.bmp");
_textureId = loadTexture(image);
delete image;
}
void handleResize(int w, int h) {
VLOG(1) << "Resizing to [" << w << " x " << h << "]";
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (float)w / (float)h, 1.0, 200.0);
}
void drawScene() {
VLOG(3) << "Drawing scene...";
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0f, 0.0f, -20.0f);
GLfloat ambientLight[] = {0.3f, 0.3f, 0.3f, 1.0f};
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambientLight);
GLfloat lightColor[] = {0.7f, 0.7f, 0.7f, 1.0f};
GLfloat lightPos[] = {-2 * BOX_SIZE, BOX_SIZE, 4 * BOX_SIZE, 1.0f};
glLightfv(GL_LIGHT0, GL_DIFFUSE, lightColor);
glLightfv(GL_LIGHT0, GL_POSITION, lightPos);
glRotatef(-_angle, 1.0f, 1.0f, 0.0f);
glBegin(GL_QUADS);
//Top face
glColor3f(1.0f, 1.0f, 0.0f);
glNormal3f(0.0, 1.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, BOX_SIZE / 2, -BOX_SIZE / 2);
glVertex3f(-BOX_SIZE / 2, BOX_SIZE / 2, BOX_SIZE / 2);
glVertex3f(BOX_SIZE / 2, BOX_SIZE / 2, BOX_SIZE / 2);
glVertex3f(BOX_SIZE / 2, BOX_SIZE / 2, -BOX_SIZE / 2);
//Bottom face
glColor3f(1.0f, 0.0f, 1.0f);
glNormal3f(0.0, -1.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, -BOX_SIZE / 2, -BOX_SIZE / 2);
glVertex3f(BOX_SIZE / 2, -BOX_SIZE / 2, -BOX_SIZE / 2);
glVertex3f(BOX_SIZE / 2, -BOX_SIZE / 2, BOX_SIZE / 2);
glVertex3f(-BOX_SIZE / 2, -BOX_SIZE / 2, BOX_SIZE / 2);
//Left face
glNormal3f(-1.0, 0.0f, 0.0f);
glColor3f(0.0f, 1.0f, 1.0f);
glVertex3f(-BOX_SIZE / 2, -BOX_SIZE / 2, -BOX_SIZE / 2);
glVertex3f(-BOX_SIZE / 2, -BOX_SIZE / 2, BOX_SIZE / 2);
glColor3f(0.0f, 0.0f, 1.0f);
glVertex3f(-BOX_SIZE / 2, BOX_SIZE / 2, BOX_SIZE / 2);
glVertex3f(-BOX_SIZE / 2, BOX_SIZE / 2, -BOX_SIZE / 2);
//Right face
glNormal3f(1.0, 0.0f, 0.0f);
glColor3f(1.0f, 0.0f, 0.0f);
glVertex3f(BOX_SIZE / 2, -BOX_SIZE / 2, -BOX_SIZE / 2);
glVertex3f(BOX_SIZE / 2, BOX_SIZE / 2, -BOX_SIZE / 2);
glColor3f(0.0f, 1.0f, 0.0f);
glVertex3f(BOX_SIZE / 2, BOX_SIZE / 2, BOX_SIZE / 2);
glVertex3f(BOX_SIZE / 2, -BOX_SIZE / 2, BOX_SIZE / 2);
glEnd();
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, _textureId);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glColor3f(1.0f, 1.0f, 1.0f);
glBegin(GL_QUADS);
//Front face
glNormal3f(0.0, 0.0f, 1.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, -BOX_SIZE / 2, BOX_SIZE / 2);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(BOX_SIZE / 2, -BOX_SIZE / 2, BOX_SIZE / 2);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(BOX_SIZE / 2, BOX_SIZE / 2, BOX_SIZE / 2);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-BOX_SIZE / 2, BOX_SIZE / 2, BOX_SIZE / 2);
//Back face
glNormal3f(0.0, 0.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, -BOX_SIZE / 2, -BOX_SIZE / 2);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, BOX_SIZE / 2, -BOX_SIZE / 2);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(BOX_SIZE / 2, BOX_SIZE / 2, -BOX_SIZE / 2);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(BOX_SIZE / 2, -BOX_SIZE / 2, -BOX_SIZE / 2);
glEnd();
glDisable(GL_TEXTURE_2D);
glutSwapBuffers();
}
//Called every 25 milliseconds
void update(int value) {
_angle += 1.0f;
if (_angle > 360) {
_angle -= 360;
}
VLOG(3) << "Updating ... [angle: " << _angle << "]";
glutPostRedisplay();
glutTimerFunc(25, update, 0);
}
int main(int argc, char** argv) {
START_EASYLOGGINGPP(argc, argv);
LOG(INFO) << "Source base taken from http://www.muflihun.com";
LOG_IF(!VLOG_IS_ON(1), INFO) << "Try using --v=1 or --v=2 or --verbose command line arguments as well";
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(400, 400);
glutCreateWindow("Great Cube Sample");
initRendering();
glutDisplayFunc(drawScene);
glutKeyboardFunc(handleKeypress);
glutReshapeFunc(handleResize);
glutTimerFunc(25, update, 0);
glutMainLoop();
return 0;
}
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