A new turn to an older post. I wish to achieve the same thing as here: http://processing.org/learning/3d/texturedsphere.html

Only instead of an sphere, I wish to texture a plane (a grid of 800 times 800). It shouldn't be too difficult, but I've spend some hours staring at the code... I intend to use an image as a heightmap to move vertices along the z-axis later. But first the grid and the texturing should be right.

Please take a look at the code and tell me what to do...

import processing.opengl.*;

PImage texmap;

float rotationX = 0;
float rotationY = 0;
float velocityX = 0;
float velocityY = 0;
float sizeSquare = 800;
float sizeQuad = 16;
float pushBack = 0;
float verX;
float verY;

float[] positionX,positionY,positionZ;
float vertexX[];
float vertexY[];
int QUAD_LENGTH = int((sizeSquare/sizeQuad)+1);


void setup()
{
 size(1280, 800, OPENGL);  
 texmap = loadImage("VincentsRoom.jpg");    
 initializeGrid(QUAD_LENGTH);
}


void draw()
{    
 background(100);            
 renderGrid();
}


void renderGrid()
{
 pushMatrix();
 translate((width/2.0 - 100), height/2.0, pushBack);
 pushMatrix();
 noFill();
 stroke(255,200);
 strokeWeight(2);
 smooth();
 popMatrix();
 lights();    
 pushMatrix();
 rotateX( radians(-rotationX) );  
 rotateY( radians(270 - rotationY) );
 fill(200);
 noStroke();
 textureMode(IMAGE);  
 texturedGrid(texmap);
 popMatrix();  
 popMatrix();
 rotationX += velocityX;
 rotationY += velocityY;
 velocityX *= 0.95;
 velocityY *= 0.95;
 
 // Implements mouse control (interaction will be inverse when sphere is  upside down)
 if(mousePressed){
   velocityX += (mouseY-pmouseY) * 0.01;
   velocityY -= (mouseX-pmouseX) * 0.01;
 }
}


void initializeGrid(int QUAD_LENGTH)
{
 // Computing vertexlist; vertexlist starts at south pole
 int vertCount = QUAD_LENGTH * (QUAD_LENGTH +1);
 //int currVert = 0;
 
 // Re-init arrays to store vertices
 positionX = new float[vertCount];
 positionY = new float[vertCount];
 positionZ = new float[vertCount];
 
 for (int i = 1; i < QUAD_LENGTH; i++) {
   for (int j = 0; j < QUAD_LENGTH; j++) {
     positionX[currVert] = i * sizeQuad;
     verX = i * sizeQuad;
     positionY[currVert] = j * sizeQuad;
     verY = j * sizeQuad;
     ellipse(verX, verY, 5, 5);
     vertex(positionX[currVert], positionY[currVert], 0);
     positionZ[currVert++] = 0;
   }
 }
}


void texturedGrid(PImage t)
{
 int v1,v11,v2;
 float iu=(float)(t.width-1)/(QUAD_LENGTH);
 float iv=(float)(t.height-1)/(QUAD_LENGTH);
 float u=0,v=iv;  
 
 int voff = 0;
 for(int i = 2; i < QUAD_LENGTH; i++) {
   v1=v11=voff;
   voff += QUAD_LENGTH;
   v2=voff;
   u=0;
   beginShape(TRIANGLE_STRIP);
   texture(t);
   for (int j = 0; j < QUAD_LENGTH; j++) {
     vertex(positionX[v1], positionY[v1], positionZ[v1], u, v);
     vertex(positionX[v2], positionY[v2], positionZ[v2], u, v+iv);
     u+=iu;
   }
   // Close
   v1=v11;
   v2=voff;
   vertex(positionX[v1], positionY[v1], positionZ[v1], u, v);
   vertex(positionX[v2], positionY[v2], positionZ[v2], u, v+iv);
   endShape();
   v+=iv;
 }
 u=0;
}

Where do I go wrong??? Please help!

I'm sorry I have two post with relating subjects. I thought it was a new subject, but appearently they are more related then I thought. I appreciate your help.

The program is part of my graduation project for which I will make digital paintings for psychological research. So if you could help me with this crucial part of my program before Monday June 23, it would be an honor to mention you in my research paper. And of course I will send you a copy of the program including my drawings for the research and  my paper in English (digitally or hard copy).

This is not only for PhiLho. Anyone who really contributes to finishing my program code gets this 'reward'; it's my pleasure!