/*****************************************************************
  tex1d.cpp
  by Dave Pape
  30 Mar 2003

*****************************************************************/
#include <stdlib.h>
#include <math.h>
#include <unistd.h>
#include <stdio.h>
#include <GL/glut.h>
#include <GL/gl.h>
#include <dms/dms.h>

using namespace dms;

void createScene(Object& root);
void make1DTexture(void);
void drawEverything(void);

void key(unsigned char k, int x, int y);
void specialkey(int k, int x, int y);
void idle(void);


PerspCamera camera;
Light light;
Object root;

int main(int argc, char *argv[])
    {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutInitWindowSize(512,512);
    glutCreateWindow(argv[0]);
    
    glutDisplayFunc(drawEverything);
    glutKeyboardFunc(key);
    glutSpecialFunc(specialkey);
    glutIdleFunc(idle);
    
    camera.setPosition(-1, 0, 8);
    light.setInfinitePosition(-1, 1, 2);
    createScene(root);
    
    glutMainLoop();
    return 0;
    }


void createScene(Object& root)
    {
    QuadricObject *ball = new QuadricObject;
    ball->makeSphere(1.0, 32, 16);
    ball->setMaterial(*(new Material(Color::White)));
    ball->setUseTexture(GL_TRUE);
    root.attach(*ball);
    make1DTexture();
    }


#define TEXTURE_WIDTH 64
GLubyte textureImage[TEXTURE_WIDTH][3];
GLuint textureID;

void make1DTexture(void)
    {
    int i;
    for (i=0; i < TEXTURE_WIDTH; i++)
        {
        textureImage[i][0] = i*255 / (TEXTURE_WIDTH-1);
        textureImage[i][1] = 255 - textureImage[i][0];
        textureImage[i][2] = 0;
        }
    glGenTextures(1, &textureID);
    glEnable(GL_TEXTURE_1D);
    glBindTexture(GL_TEXTURE_1D, textureID);
    glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexImage1D(GL_TEXTURE_1D, 0, GL_RGB, TEXTURE_WIDTH, 0, GL_RGB,
                GL_UNSIGNED_BYTE, textureImage);
    glBindTexture(GL_TEXTURE_1D, 0);
    }


void drawEverything(void)
    {
    glClearColor(0.5, 0.7, 1.0, 0.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnable(GL_DEPTH_TEST);
    
    camera.apply();
    
    light.apply();

    glEnable(GL_TEXTURE_1D);
    glBindTexture(GL_TEXTURE_1D, textureID);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
    
    glColor3f(1, 1, 1);
    glBegin(GL_QUADS);
     glTexCoord1f(0);
     glVertex3f(-3.25, -1, 0);
     glTexCoord1f(0);
     glVertex3f(-1.25, -1, 0);
     glTexCoord1f(4.5);
     glVertex3f(-1.25, 1, 0);
     glTexCoord1f(1.5);
     glVertex3f(-3.25, 1, 0);
    glEnd();
    
    root.drawAll();
    
    glBindTexture(GL_TEXTURE_1D, 0);
    glDisable(GL_TEXTURE_1D);

    glutSwapBuffers();

    checkGLError("end-of-frame");
    }


void key(unsigned char k, int x, int y)
    {
    if (k == 27)
        exit(0);
    }


void specialkey(int k, int x, int y)
    {
    if (k == GLUT_KEY_LEFT)
        camera.turn(3);
    else if (k == GLUT_KEY_RIGHT)
        camera.turn(-3);
    else if (k == GLUT_KEY_UP)
        camera.pitch(2);
    else if (k == GLUT_KEY_DOWN)
        camera.pitch(-2);
    else if (k == GLUT_KEY_HOME)
        camera.moveForward(0.25);
    else if (k == GLUT_KEY_END)
        camera.moveForward(-0.25);
    else if (k == GLUT_KEY_PAGE_UP)
        camera.zoom(-1);
    else if (k == GLUT_KEY_PAGE_DOWN)
        camera.zoom(1);
    }


void idle(void)
    {
    root.updateAll();
    glutPostRedisplay();
    }