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/*
* Modification History
*
* 2001-January-9 Jason Rohrer
* Created. Copied from LandscapePrimitiveGL, which this class will replace
*
* 2001-January-15 Jason Rohrer
* Fixed a bug in the constructor.
*
* 2001-January-17 Jason Rohrer
* Fliped how x and y in height map correspond to x and z in the terrain.
*
* 2001-January-19 Jason Rohrer
* Changed to support multi-texturing.
*
* 2001-January-30 Jason Rohrer
* Fixed a bug that occurs when the class defaults to no detail texture.
*
* 2001-March-11 Jason Rohrer
* Fixed a bug in the texture map anchor points.
*/
#ifndef LANDSCAPE_PRIMITIVE_3D_INCLUDED
#define LANDSCAPE_PRIMITIVE_3D_INCLUDED
#include "Primitive3D.h"
/**
* Primitive 3D lanscape object.
*
* Made from a height map. Mesh generated spans both x and z between -1 and
* 1, and can vary in height (y) from 0 to 1.
*
* @author Jason Rohrer
*/
class LandscapePrimitive3D : public Primitive3D {
public:
/**
* Constructs a LandscapePrimitive with a multi-layer texture.
*
* @param inWide width of mesh in number of vertices.
* Must be even and at least 2.
* @param inHigh height of mesh in number of vertices.
* @param inHeights array of heights for each vertex, each in
* [0,1]. Must be destroyed by caller.
* @param inTexture the texture to map onto the lanscape.
* Texture is anchored by its corners to the corners of the
* lanscape. inTexture is destroyed when primitive is destroyed.
* @param inDetailTexture the second layer in the multi-texture.
* The alpha channel of inDetailTexture will be used as
* the blending factor to mix the detail with the global texture.
* Set to NULL to use only a single layer.
* @param inDetailScale the scale factor of the detailed texture.
* Setting to 1.0 will anchor the detail at the corners of the
* mesh (just like inTexture). Setting to 0.25 will cause
* the detail texture to cycle 4 times across the surface of the
* mesh.
*/
LandscapePrimitive3D( int inWide, int inHigh, double *inHeights,
RGBAImage *inTexture, RGBAImage *inDetailTexture = NULL,
double inDetailScale = 1.0 );
};
inline LandscapePrimitive3D::LandscapePrimitive3D( int inWide,
int inHigh, double *inHeights,
RGBAImage *inTexture, RGBAImage *inDetailTexture,
double inDetailScale ) {
// first, set Primitve3D members
mHigh = inHigh;
mWide = inWide;
mNumVertices = mHigh * mWide;
if( inDetailTexture == NULL ) {
mNumTextures = 1;
mTexture = new RGBAImage*[1];
mTexture[0] = inTexture;
mAnchorX = new double*[1];
mAnchorY = new double*[1];
mAnchorX[0] = new double[mNumVertices];
mAnchorY[0] = new double[mNumVertices];
}
else {
mNumTextures = 2;
mTexture = new RGBAImage*[2];
mTexture[0] = inTexture;
mTexture[1] = inDetailTexture;
mAnchorX = new double*[2];
mAnchorY = new double*[2];
mAnchorX[0] = new double[mNumVertices];
mAnchorY[0] = new double[mNumVertices];
mAnchorX[1] = new double[mNumVertices];
mAnchorY[1] = new double[mNumVertices];
}
mVertices = new Vector3D*[mNumVertices];
// anchor at texture corners, and step linearly through texture
double anchorYStep = 1.0 / ( mHigh - 1 );
double anchorXStep = 1.0 / ( mWide - 1 );
double detailAnchorYStep = 1.0 / ( ( mHigh - 1 ) * inDetailScale );
double detailAnchorXStep = 1.0 / ( ( mWide - 1 ) * inDetailScale );
for( int y=0; y<mHigh; y++ ) {
for( int x=0; x<mWide; x++ ) {
int index = y * mWide + x;
mAnchorX[0][index] = anchorXStep * x;
mAnchorY[0][index] = anchorYStep * y;
if( mNumTextures == 2 ) {
mAnchorX[1][index] = detailAnchorXStep * x;
mAnchorY[1][index] = detailAnchorYStep * y;
}
// add height for this x and y position
mVertices[index] = new Vector3D( 2 * mAnchorX[0][index] - 1,
inHeights[index], -2 * mAnchorY[0][index] + 1 );
// note that y coordinates in the 2d height map must be
// inverted before they can be used as z coordinates in the mesh
}
}
generateNormals();
}
#endif
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