#include <GL/gl.h>
#include <GL/glu.h>
#include "aux.h"


GLfloat diffuseMaterial[4] = { 0.5, 0.5, 0.5, 1.0 };

void myinit(void)
{
    GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
    GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };

    glMaterialfv(GL_FRONT, GL_DIFFUSE, diffuseMaterial);
    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
    glMaterialf(GL_FRONT, GL_SHININESS, 25.0);
    glLightfv(GL_LIGHT0, GL_POSITION, light_position);

    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glDepthFunc(GL_LESS);
    glEnable(GL_DEPTH_TEST);

    glColorMaterial(GL_FRONT, GL_DIFFUSE);
    glEnable(GL_COLOR_MATERIAL);
}

void changeRedDiffuse (AUX_EVENTREC *event)
{
    diffuseMaterial[0] += 0.1;
    if (diffuseMaterial[0] > 1.0)
	diffuseMaterial[0] = 0.0;
    glColor4fv(diffuseMaterial);
}

void changeGreenDiffuse (AUX_EVENTREC *event)
{
    diffuseMaterial[1] += 0.1;
    if (diffuseMaterial[1] > 1.0)
	diffuseMaterial[1] = 0.0;
    glColor4fv(diffuseMaterial);
}

void changeBlueDiffuse (AUX_EVENTREC *event)
{
    diffuseMaterial[2] += 0.1;
    if (diffuseMaterial[2] > 1.0)
	diffuseMaterial[2] = 0.0;
    glColor4fv(diffuseMaterial);
}

void display(void)
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    auxSolidSphere(1.0);
    glFlush();
}

void myReshape(int w, int h)
{
    glViewport(0, 0, w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if (w <= h) 
	glOrtho (-1.5, 1.5, -1.5*(GLfloat)h/(GLfloat)w, 
	    1.5*(GLfloat)h/(GLfloat)w, -10.0, 10.0);
    else 
	glOrtho (-1.5*(GLfloat)w/(GLfloat)h, 
	    1.5*(GLfloat)w/(GLfloat)h, -1.5, 1.5, -10.0, 10.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}

int main(int argc, char** argv)
{
    auxInitDisplayMode (AUX_SINGLE | AUX_RGB | AUX_DEPTH);
    auxInitPosition (0, 0, 500, 500);
    auxInitWindow (argv[0]);
    myinit();
    auxMouseFunc (AUX_LEFTBUTTON, AUX_MOUSEDOWN, changeRedDiffuse);
    auxMouseFunc (AUX_MIDDLEBUTTON, AUX_MOUSEDOWN, changeGreenDiffuse);
    auxMouseFunc (AUX_RIGHTBUTTON, AUX_MOUSEDOWN, changeBlueDiffuse);
    auxReshapeFunc (myReshape);
    auxMainLoop(display);
}