assessment3.2.cpp

/* Rotating cube with color interpolation */


#include <stdlib.h>

#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
#include "lodepng.h"
#include <vector>
#include <string>
#include <iostream>

	GLfloat vertices[][3] = {{-1.0,-1.0,-1.0},{1.0,-1.0,-1.0},
	{1.0,1.0,-1.0}, {-1.0,1.0,-1.0}, {-1.0,-1.0,1.0},
	{1.0,-1.0,1.0}, {1.0,1.0,1.0}, {-1.0,1.0,1.0}};

	GLfloat colors[][3] = {{1.0,0.0,0.0},{0.0,1.0,0.0},
	{0.0,0.0,1.0}, {1.0,1.0,0.0}, {0.0,1.0,1.0},
	{1.0,0.0,1.0}};

struct Image
{
	unsigned int width, height;
	std::vector<unsigned char> data;
	std::string url;

	unsigned int load()
	{
		unsigned int error = lodepng::decode(this->data, this->width, this->height, this->url.c_str());
		return error;
	}

	void draw()
	{
		glEnable(GL_TEXTURE_2D);
  	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); //GL_NEAREST = no smoothing
  	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  	glTexImage2D(GL_TEXTURE_2D, 0, 4, this->width, this->height, 0, GL_RGBA, GL_UNSIGNED_BYTE, &this->data[0]);
	}
};

Image images[2];

void loadTextures()
{
	images[0].url = "avatar.png";
	std::cout << images[0].load() << std::endl;
	images[1].url = "1gam.png";
	std::cout << images[1].load() << std::endl;
}

void polygon(int a, int b, int c , int d)
{

/* draw a polygon via list of vertices */

 	glBegin(GL_POLYGON);
		glTexCoord2d( 0,  0);
		glVertex3fv(vertices[a]);
		glTexCoord2d( 1,  0);
		glVertex3fv(vertices[b]);
		glTexCoord2d( 1,  1);
		glVertex3fv(vertices[c]);
		glTexCoord2d( 0,  1);
		glVertex3fv(vertices[d]);
	glEnd();
																										}

void colorcube(void)
{

/* map vertices to faces */

	glColor3fv(colors[0]);
	images[0].draw();
	polygon(0,3,2,1);
	glColor3fv(colors[1]);
	polygon(2,3,7,6);
	images[1].draw();
	glColor3fv(colors[2]);
	polygon(3,0,4,7);
	images[0].draw();
	glColor3fv(colors[3]);
	polygon(1,2,6,5);
	glColor3fv(colors[4]);
	polygon(4,5,6,7);
	images[1].draw();
	glColor3fv(colors[5]);
	polygon(5,4,0,1);
}

static GLfloat theta[] = {0.0,0.0,0.0};
static GLint axis = 2;

void display(void)
{
/* display callback, clear frame buffer and z buffer,
   rotate cube and draw, swap buffers */

 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();
	glRotatef(theta[0], 1.0, 0.0, 0.0);
	glRotatef(theta[1], 0.0, 1.0, 0.0);
	glRotatef(theta[2], 0.0, 0.0, 1.0);

 colorcube();

 glFlush();
	glutSwapBuffers();
}

void spinCube()
{

/* Idle callback, spin cube 2 degrees about selected axis */

	theta[axis] += 2.0;
	if( theta[axis] > 360.0 ) theta[axis] -= 360.0;
	/* display(); */
	glutPostRedisplay();
}

void mouse(int btn, int state, int x, int y)
{

/* mouse callback, selects an axis about which to rotate */

	if(btn==GLUT_LEFT_BUTTON && state == GLUT_DOWN) axis = 0;
	if(btn==GLUT_MIDDLE_BUTTON && state == GLUT_DOWN) axis = 1;
	if(btn==GLUT_RIGHT_BUTTON && state == GLUT_DOWN) axis = 2;
}

void myReshape(int w, int h)
{
    glViewport(0, 0, w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if (w <= h)
        glOrtho(-2.0, 2.0, -2.0 * (GLfloat) h / (GLfloat) w,
            2.0 * (GLfloat) h / (GLfloat) w, -10.0, 10.0);
    else
        glOrtho(-2.0 * (GLfloat) w / (GLfloat) h,
            2.0 * (GLfloat) w / (GLfloat) h, -2.0, 2.0, -10.0, 10.0);
    glMatrixMode(GL_MODELVIEW);
}

int main(int argc, char **argv)
{
    glutInit(&argc, argv);

/* need both double buffering and z buffer */
		loadTextures();
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(500, 500);
    glutCreateWindow("colorcube");
    glutReshapeFunc(myReshape);
    glutDisplayFunc(display);
	   glutIdleFunc(spinCube);
	   glutMouseFunc(mouse);
	   glEnable(GL_DEPTH_TEST); /* Enable hidden--surface--removal */
    glutMainLoop();
    return 0;
}