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View Full Version : Help! I can't get my lighting or textures to work



marbles
10-30-2012, 02:36 PM
I started learning openGL a few months ago for a class and I'm in way over my head. I think I have most of the basics down but I just can't get my lighting or textures to work. It complies fine, but none of the lighting on my cube is showing up and neither is the texture. I think that I need to link the texture bmp to the file so my computer can find it but I'm not sure exactly how to do that. Here is my source code:



#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <math.h>
#define GL_GLEXT_PROTOTYPES
#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif

int axes=1; // Display axes
int mode=1; // Projection mode
int move=1; // Move light
int th=0; // Azimuth of view angle
int ph=0; // Elevation of view angle
int fov=55; // Field of view (for perspective)
int light=1; // Lighting
double asp=1; // Aspect ratio
double dim=3.0; // Size of world
// Light values
int emission = 0; // Emission intensity (%)
int ambient = 30; // Ambient intensity (%)
int diffuse = 100; // Diffuse intensity (%)
int specular = 0; // Specular intensity (%)
int shininess = 0; // Shininess (power of two)
float shinyvec[1]; // Shininess (value)
int zh = 90; // Light azimuth
float ylight = 0; // Elevation of light
int ntex=0; // Cube faces
int rep=1; // Repitition
unsigned int texture[1]; // Texture names
int distance = 5; // Light distance
int local = 0; // Local Viewer Model



// Cosine and Sine in degrees
#define Cos(x) (cos((x)*3.1415927/180))
#define Sin(x) (sin((x)*3.1415927/180))




/*
* Draw a cube
* at (x,y,z)
* dimentions (dx,dy,dz)
* rotated th about the y axis
*/
static void cube(double x,double y,double z,
double dx,double dy,double dz,
double th)

{
// Set specular color to white
float white[] = {1,1,1,1};
float Emission[] = {0.0,0.0,0.1*emission,1.0};
glMaterialfv(GL_FRONT_AND_BACK,GL_SHININESS,shinyv ec);
glMaterialfv(GL_FRONT_AND_BACK,GL_SPECULAR,white);
glMaterialfv(GL_FRONT_AND_BACK,GL_EMISSION,Emissio n);
// Save transformation
glPushMatrix();
// Offset, scale and rotate
glTranslated(x,y,z);
glRotated(th,0,1,0);
glScaled(dx,dy,dz);
// Enable textures
glEnable(GL_TEXTURE_2D);
glTexEnvi(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,mode? GL_REPLACE:GL_MODULATE);
glColor3f(1,1,1);
glBindTexture(GL_TEXTURE_2D,texture[0]);
// Front
glColor3f(1,0,0);
if (ntex) glBindTexture(GL_TEXTURE_2D,texture[1]);
glBegin(GL_QUADS);
glNormal3f( 0, 0, 1);
glTexCoord2f(0,0); glVertex3f(-1,-1, 1);
glTexCoord2f(1,0); glVertex3f(+1,-1, 1);
glTexCoord2f(1,1); glVertex3f(+1,+1, 1);
glTexCoord2f(0,1); glVertex3f(-1,+1, 1);
glEnd();
// Back
glColor3f(0,0,1);
if (ntex) glBindTexture(GL_TEXTURE_2D,texture[1]);
glBegin(GL_QUADS);
glNormal3f( 0, 0,-1);
glTexCoord2f(0,0); glVertex3f(+1,-1,-1);
glTexCoord2f(1,0); glVertex3f(-1,-1,-1);
glTexCoord2f(1,1); glVertex3f(-1,+1,-1);
glTexCoord2f(0,1); glVertex3f(+1,+1,-1);
glEnd();
// Right
glColor3f(1,1,0);
if (ntex) glBindTexture(GL_TEXTURE_2D,texture[1]);
glBegin(GL_QUADS);
glNormal3f(+1, 0, 0);
glTexCoord2f(0,0); glVertex3f(+1,-1,+1);
glTexCoord2f(1,0); glVertex3f(+1,-1,-1);
glTexCoord2f(1,1); glVertex3f(+1,+1,-1);
glTexCoord2f(0,1); glVertex3f(+1,+1,+1);
glEnd();
// Left
glColor3f(0,1,0);
if (ntex) glBindTexture(GL_TEXTURE_2D,texture[1]);
glBegin(GL_QUADS);
glNormal3f(-1, 0, 0);
glTexCoord2f(0,0); glVertex3f(-1,-1,-1);
glTexCoord2f(1,0); glVertex3f(-1,-1,+1);
glTexCoord2f(1,1); glVertex3f(-1,+1,+1);
glTexCoord2f(0,1); glVertex3f(-1,+1,-1);
glEnd();
// Top
glColor3f(0,1,1);
if (ntex) glBindTexture(GL_TEXTURE_2D,texture[1]);
glBegin(GL_QUADS);
glNormal3f( 0,+1, 0);
glTexCoord2f(0,0); glVertex3f(-1,+1,+1);
glTexCoord2f(1,0); glVertex3f(+1,+1,+1);
glTexCoord2f(1,1); glVertex3f(+1,+1,-1);
glTexCoord2f(0,1); glVertex3f(-1,+1,-1);
glEnd();
// Bottom
glColor3f(1,0,1);
if (ntex) glBindTexture(GL_TEXTURE_2D,texture[1]);
glBegin(GL_QUADS);
glNormal3f( 0,-1, 0);
glTexCoord2f(0,0); glVertex3f(-1,-1,-1);
glTexCoord2f(1,0); glVertex3f(+1,-1,-1);
glTexCoord2f(1,1); glVertex3f(+1,-1,+1);
glTexCoord2f(0,1); glVertex3f(-1,-1,+1);
glEnd();
// Undo transformations and textures
glPopMatrix();
glDisable(GL_TEXTURE_2D);
}

static void ball(double x,double y,double z,double r)
{
// Save transformation
glPushMatrix();
// Offset, scale and rotate
glTranslated(x,y,z);
glScaled(r,r,r);
// White ball
glColor3f(1,1,1);
glutSolidSphere(1.0,16,16);
// Undo transofrmations
glPopMatrix();
}

// Projection
static void Project()
{
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (mode)
gluPerspective(fov,asp,dim/3,3*dim);
else
glOrtho(-asp*dim,+asp*dim,-dim,+dim,-dim,+dim);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}

void display()
{
const double len=2.0; // Length of axes
// Erase the window and the depth buffer
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
// Enable Z-buffering in OpenGL
glEnable(GL_DEPTH_TEST);

// Undo previous transformations
glLoadIdentity();
// Perspective - set eye position
if (mode)
{
double Ex = -2*dim*Sin(th)*Cos(ph);
double Ey = +2*dim *Sin(ph);
double Ez = +2*dim*Cos(th)*Cos(ph);
gluLookAt(Ex,Ey,Ez,0,0,0,0,Cos(ph),0);
}
// Orthogonal - set world orientation
else
{
glRotatef(ph,1,0,0);
glRotatef(th,0,1,0);
}
// Light switch
if (light)
{
// Translate intensity to color vectors
float Ambient[] = {0.01*ambient ,0.01*ambient ,0.01*ambient ,1.0};
float Diffuse[] = {0.01*diffuse ,0.01*diffuse ,0.01*diffuse ,1.0};
float Specular[] = {0.01*specular,0.01*specular,0.01*specular,1.0};
// Light position
float Position[] = {distance*Cos(zh),ylight,distance*Sin(zh),1.0};
// Draw light position as ball (still no lighting here)
glColor3f(1,1,1);
ball(Position[0],Position[1],Position[2] , 0.1);
// OpenGL should normalize normal vectors
glEnable(GL_NORMALIZE);
// Enable lighting
glEnable(GL_LIGHTING);
// Location of viewer for specular calculations
glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER,local);
// glColor sets ambient and diffuse color materials
glColorMaterial(GL_FRONT_AND_BACK,GL_AMBIENT_AND_D IFFUSE);
glEnable(GL_COLOR_MATERIAL);
// Enable light 0
glEnable(GL_LIGHT0);
// Set ambient, diffuse, specular components and position of light 0
glLightfv(GL_LIGHT0,GL_AMBIENT ,Ambient);
glLightfv(GL_LIGHT0,GL_DIFFUSE ,Diffuse);
glLightfv(GL_LIGHT0,GL_SPECULAR,Specular);
glLightfv(GL_LIGHT0,GL_POSITION,Position);
}

// Draw scene
cube(+1,0,0,0.5,0.5,0.5,0);
ball(-1,0,0,0.5);

// Draw axes - no lighting from here on
glDisable(GL_LIGHTING);
glColor3f(1,1,1);
if (axes)
{
glBegin(GL_LINES);
glVertex3d(0.0,0.0,0.0);
glVertex3d(len,0.0,0.0);
glVertex3d(0.0,0.0,0.0);
glVertex3d(0.0,len,0.0);
glVertex3d(0.0,0.0,0.0);
glVertex3d(0.0,0.0,len);
glEnd();
}

// Render the scene and make it visible
glFlush();
glutSwapBuffers();
}

void special(int key,int x,int y)
{
if (key == GLUT_KEY_RIGHT)
th += 5;
else if (key == GLUT_KEY_LEFT)
th -= 5;
else if (key == GLUT_KEY_UP)
ph += 5;
else if (key == GLUT_KEY_DOWN)
ph -= 5;
th %= 360;
ph %= 360;
Project();
glutPostRedisplay();
}

void key(unsigned char ch,int x, int y)
{
// Exit on ESC
if (ch == 27)
exit(0);
// Switch display mode
else if (ch == 'p' || ch == 'P')
mode = 1-mode;
// Changle fov
else if (ch == '-' && ch>1)
fov--;
else if (ch == '+' && ch<179)
fov++;
// Toggle lighting
else if (ch == 'l' || ch == 'L')
light = 1-light;
// Toggle light movement
else if (ch == 'm' || ch == 'M')
move = 1-move;
// Move light
else if (ch == '<')
zh += 1;
else if (ch == '>')
zh -= 1;
// Light elevation
else if (ch=='[')
ylight -= 0.1;
else if (ch==']')
ylight += 0.1;
// Ambient level
else if (ch=='a' && ambient>0)
ambient -= 5;
else if (ch=='A' && ambient<100)
ambient += 5;
// Diffuse level
else if (ch=='d' && diffuse>0)
diffuse -= 5;
else if (ch=='D' && diffuse<100)
diffuse += 5;
// Specular level
else if (ch=='s' && specular>0)
specular -= 5;
else if (ch=='S' && specular<100)
specular += 5;
// Emission level
else if (ch=='e' && emission>0)
emission -= 5;
else if (ch=='E' && emission<100)
emission += 5;
// Shininess level
else if (ch=='n' && shininess>-1)
shininess -= 1;
else if (ch=='N' && shininess<7)
shininess += 1;
// Translate shininess power to value (-1 => 0)
shinyvec[0] = shininess<0 ? 0 : pow(2.0,shininess);
// Reproject
Project(mode?fov:0,asp,dim);
glutPostRedisplay();
}

void reshape(int width,int height)
{
asp = (height>0) ? (double)width/height : 1;
glViewport(0,0,width,height);
Project();
}

/*
* GLUT calls this routine when there is nothing else to do
*/
void idle()
{
double t = glutGet(GLUT_ELAPSED_TIME)/1000.0;
glutPostRedisplay();
}

/*
* Start up GLUT and tell it what to do
*/
int main(int argc,char* argv[])
{
// Initialize GLUT and process user parameters
glutInit(&argc,argv);
// Request double buffered, true color window with Z buffering at 600x600
glutInitWindowSize(600,600);
glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
// Create the window
glutCreateWindow("hw7");
// Tell GLUT to call "idle" when there is nothing else to do
glutIdleFunc(idle);
// Tell GLUT to call "display" when the scene should be drawn
glutDisplayFunc(display);
// Tell GLUT to call "reshape" when the window is resized
glutReshapeFunc(reshape);
// Tell GLUT to call "special" when an arrow key is pressed
glutSpecialFunc(special);
// Tell GLUT to call "key" when a key is pressed
glutKeyboardFunc(key);
// Texture
texture[1] = LoadTexBMP("texture1.bmp");
// Pass control to GLUT so it can interact with the user
glutMainLoop();
return 0;
}


Any help would be greatly appreciated!