source: orxonox.OLD/orxonox/branches/nico/src/heightMap/heightMapTerrain.cpp @ 3381

/*
 *  ldrawparser.cpp
 *  legotown3d
 *
 *  Created by Nico Bernold on 08.01.05.
 *  Copyright 2005 __MyCompanyName__. All rights reserved.
 *
 */

#include "heightMapTerrain.h"

HeightMapTerrain::HeightMapTerrain()
{       
}

HeightMapTerrain::~HeightMapTerrain()
{
}

bool HeightMapTerrain::loadBitmap(char* fileName)
{
        return bitmap = SDL_LoadBMP(fileName);  
}

bool HeightMapTerrain::createDisplayLists(int width, int height, int levelOfDetail)
{
        if (bitmap == NULL) return false;
        
        cout << "bitmap-dimensions: " << bitmap->w << "x" << bitmap->h << endl;
        
        if (bitmap->w % width != 0) return false;
        if (bitmap->h % height != 0) return false;
        
        if (levelOfDetail < 1 || levelOfDetail > 10) return false;
        
        int howManyListsWide = bitmap->w / width;
        int howManyListsHigh = bitmap->h / height;
        
        // calculate how many displayLists we'll create
        displayListCount = howManyListsWide * howManyListsHigh; 

        cout << "lists-information: " << howManyListsWide << " * " << howManyListsHigh << " = " << displayListCount << " display lists." << endl;
        
        displayListStart = glGenLists(displayListCount);
        if (displayListStart == 0)
        {
                cout << "could not generate " << displayListCount << " display lists. exiting. " << endl;
                return false;
        }

        int i,j;
        
        for (i=0; i<howManyListsHigh; i++)
        {
                for (j=0; j<howManyListsWide; j++)
                {
                        if (readIntoList(j*width,i*height,width,height,levelOfDetail,i*howManyListsHigh + j) == false)
                        {
                                cout << "error while generating display lists. exiting. " << endl;
                                return false;
                        }

                }
        }
        
        return true;
}

bool HeightMapTerrain::readIntoList(int left, int top, int width, int height, int levelOfDetail, GLuint displayListNr)
{
        // y is the height value in OpenGL convention
        GLuint x,y,z;
        GLfloat col;
        
        cout << "creating list Nr " << displayListNr << endl;
        cout << "left, top, width, height: " << left << ", " << top << ", " << width << ", " << height << endl; 
        
        glNewList(displayListNr,GL_COMPILE);
        {
                for (z=top; z<top+height; z++)
                {
                        glBegin(GL_QUAD_STRIP);
                        {
                                for (x=left; x<left+width; x++)
                                {
                                        y = heightValue(x,z+1);
                                        col = y / 256.0;
                                        glColor3f(1.0,0.0,0.0);
                                        glVertex3i(x,y,z+1);
                                        
                                        y = heightValue(x,z);
                                        col = y / 256.0;
                                        glColor3f(1.0,0.0,0.0);
                                        glVertex3i(x,y,z);
                                }
                        }
                        glEnd();
                }
                
        }
        glEndList();
        
        return true;
}

GLint HeightMapTerrain::heightValue(Uint8 x, Uint8 z)
{
        return 100;
        
        /*
        if (bitmap == NULL) return 0;
        
        Uint8 index;
        SDL_Color* color = NULL;
        
        
        SDL_LockSurface(bitmap);
        
        index = *((Uint8*)bitmap->pixels[z * bitmap->h + x]);
        color = &bitmap->format->palette->colors[index];
        
        SDL_UnlockSurface(bitmap);

        return color->r;
         */
}