static float terrainComputeLightFactor(int i,int j,int offseti, int offsetj) {
float factor,v[3];
if (terrainNormals != NULL) {
if (terrainLightPos[3] == 0.0) /* directional light */
factor = terrainNormals[3*(i * terrainGridWidth + j)] * terrainLightPos[0] +
terrainNormals[3*(i * terrainGridWidth + j) +1] * terrainLightPos[1] +
terrainNormals[3*(i * terrainGridWidth + j) +2] * terrainLightPos[2];
else { /* positional light */
v[0] = terrainLightPos[0] - ((j + offsetj) + transX) * scaleX;
v[1] = terrainLightPos[1] - terrainHeights[i*terrainGridWidth + j] + transY;
v[2] = terrainLightPos[2] - ((offseti -i) + transZ) * scaleZ;
terrainNormalize(v);
factor = terrainNormals[3*(i * terrainGridWidth + j)] * v[0] +
terrainNormals[3*(i * terrainGridWidth + j) +1] * v[1] +
terrainNormals[3*(i * terrainGridWidth + j) +2] * v[2];
}
if (factor < 0)
factor = 0;
}
else
factor = 1;
return(factor);
}
void terrainLightPosition(float x, float y, float z,float w) {
terrainLightPos[0] = x;
terrainLightPos[1] = y;
terrainLightPos[2] = z;
terrainLightPos[3] = w;
/* normalise this vector to save time later */
if (terrainLightPos[3] == 0.0)
terrainNormalize(terrainLightPos);
}
static float terrainComputeLightFactor(int i,int j,int offseti, int offsetj) {
float factor,v[3];
if (terrainLightPos[3] == 0.0) /* directional light */
factor = terrainNormals[3*(i * terrainGridWidth + j)] * terrainLightPos[0] +
terrainNormals[3*(i * terrainGridWidth + j) +1] * terrainLightPos[1] +
terrainNormals[3*(i * terrainGridWidth + j) +2] * terrainLightPos[2];
else { /* positional light */
v[0] = terrainLightPos[0] - (j + offsetj)*terrainStepWidth;
v[1] = terrainLightPos[1] - terrainHeights[i*terrainGridWidth + j];
v[2] = terrainLightPos[2] - (offseti -i) * terrainStepLength;
terrainNormalize(v);
factor = terrainNormals[3*(i * terrainGridWidth + j)] * v[0] +
terrainNormals[3*(i * terrainGridWidth + j) +1] * v[1] +
terrainNormals[3*(i * terrainGridWidth + j) +2] * v[2];
}
if (factor < 0)
factor = 0;
return(factor);
}
void terrainComputeNormals() {
float *norm1,*norm2,*norm3,*norm4;
int i,j,k;
if (terrainNormals == NULL)
return;
for(i = 0; i < terrainGridLength; i++)
for(j = 0; j < terrainGridWidth; j++) {
norm1 = NULL;
norm2 = NULL;
norm3 = NULL;
norm4 = NULL;
/* normals for the four corners */
if (i == 0 && j == 0) {
norm1 = terrainCrossProduct(0,0, 0,1, 1,0);
terrainNormalize(norm1);
}
else if (j == terrainGridWidth-1 && i == terrainGridLength-1) {
norm1 = terrainCrossProduct(j,i, j,i-1, j-1,i);
terrainNormalize(norm1);
}
else if (j == 0 && i == terrainGridLength-1) {
norm1 = terrainCrossProduct(j,i, j+1,i, j,i-1);
terrainNormalize(norm1);
}
else if (j == terrainGridWidth-1 && i == 0) {
norm1 = terrainCrossProduct(j,i, j-1,i, j,i+1);
terrainNormalize(norm1);
}
/* normals for the borders */
else if (i == 0) {
norm1 = terrainCrossProduct(j,0, j-1,0, j,1);
terrainNormalize(norm1);
norm2 = terrainCrossProduct(j,0,j,1,j+1,0);
terrainNormalize(norm2);
terrainAddVector(norm1,norm2);
free(norm2);
}
else if (j == 0) {
norm1 = terrainCrossProduct(0,i, 1,i, 0,i-1);
terrainNormalize(norm1);
norm2
= terrainCrossProduct(0,i, 0,i+1, 1,i);
terrainNormalize(norm2);
terrainAddVector(norm1,norm2);
free(norm2);
}
else if (i == terrainGridLength-1) {
norm1 = terrainCrossProduct(j,i, j+1,i, j,i-1);
terrainNormalize(norm1);
norm2 = terrainCrossProduct(j,i, j,i-1, j-1,i);
terrainNormalize(norm2);
terrainAddVector(norm1,norm2);
free(norm2);
}
else if (j == terrainGridWidth-1) {
norm1 = terrainCrossProduct(j,i, j,i-1, j-1,i);
terrainNormalize(norm1);
norm2 = terrainCrossProduct(j,i, j-1,i, j,i+1);
terrainNormalize(norm2);
terrainAddVector(norm1,norm2);
free(norm2);
}
/* normals for the inner vertices using 8 neighbours */
else {
norm1 = terrainCrossProduct(j,i, j-1,i, j-1,i+1);
terrainNormalize(norm1);
norm2 = terrainCrossProduct(j,i, j-1,i+1, j,i+1);
terrainNormalize(norm2);
terrainAddVector(norm1,norm2);
free(norm2);
norm2 = terrainCrossProduct(j,i, j,i+1, j+1,i+1);
terrainNormalize(norm2);
terrainAddVector(norm1,norm2);
free(norm2);
norm2 = terrainCrossProduct(j,i, j+1,i+1, j+1,i);
terrainNormalize(norm2);
terrainAddVector(norm1,norm2);
free(norm2);
norm2 = terrainCrossProduct(j,i, j+1,i, j+1,i-1);
terrainNormalize(norm2);
terrainAddVector(norm1,norm2);
free(norm2);
norm2 = terrainCrossProduct(j,i, j+1,i-1, j,i-1);
terrainNormalize(norm2);
terrainAddVector(norm1,norm2);
free(norm2);
norm2 = terrainCrossProduct(j,i, j,i-1, j-1,i-1);
terrainNormalize(norm2);
terrainAddVector(norm1,norm2);
free(norm2);
norm2 = terrainCrossProduct(j,i, j-1,i-1, j-1,i);
terrainNormalize(norm2);
terrainAddVector(norm1,norm2);
free(norm2);
}
terrainNormalize(norm1);
norm1[2] = - norm1[2];
for (k = 0; k< 3; k++)
terrainNormals[3*(i*terrainGridWidth + j) + k] = norm1[k];
free(norm1);
}
}
void terrainComputeNormals() {
float *norm1,*norm2,*norm3,*norm4;
int i,j,k;
if (terrainNormals == NULL)
return;
for(i = 0; i < length; i++)
for(j = 0; j < width; j++)
{
norm1 = NULL;
norm2 = NULL;
norm3 = NULL;
norm4 = NULL;
// normals for the four corners
if (i == 0 && j == 0) {
norm1 = terrainCrossProduct(0,0, 0,1, 1,0);
terrainNormalize(norm1);
}
else if (j == width-1 && i == length-1) {
norm1 = terrainCrossProduct(i,j, j,i-1, j-1,i);
terrainNormalize(norm1);
}
else if (j == 0 && i == length-1) {
norm1 = terrainCrossProduct(i,j, j,i-1, j+1,i);
terrainNormalize(norm1);
}
else if (j == width-1 && i == 0) {
norm1 = terrainCrossProduct(i,j, j,i+1, j-1,i);
terrainNormalize(norm1);
}
// normals for the borders
else if (i == 0) {
norm1 = terrainCrossProduct(j,0, j-1,0, j,1);
terrainNormalize(norm1);
norm2 = terrainCrossProduct(j,0,j,1,j+1,0);
terrainNormalize(norm2);
}
else if (j == 0) {
norm1 = terrainCrossProduct(0,i, 1,i, 0,i-1);
terrainNormalize(norm1);
norm2 = terrainCrossProduct(0,i, 0,i+1, 1,i);
terrainNormalize(norm2);
}
else if (i == length-1) {
norm1 = terrainCrossProduct(j,i, j,i-1, j+1,i);
terrainNormalize(norm1);
norm2 = terrainCrossProduct(j,i, j+1,i, j,i-1);
terrainNormalize(norm2);
}
else if (j == width-1) {
norm1 = terrainCrossProduct(j,i, j,i-1, j-1,i);
terrainNormalize(norm1);
norm2 = terrainCrossProduct(j,i, j-1,i, j,i+1);
terrainNormalize(norm2);
}
// normals for the interior
else {
norm1 = terrainCrossProduct(j,i, j-1,i, j,i+1);
terrainNormalize(norm1);
norm2 = terrainCrossProduct(j,i, j,i+1, j+1,i);
terrainNormalize(norm2);
norm3 = terrainCrossProduct(j,i, j+1,i, j,i-1);
terrainNormalize(norm3);
norm4 = terrainCrossProduct(j,i, j,i-1, j-1,i);
terrainNormalize(norm4);
}
if (norm2 != NULL) {
terrainAddVector(norm1,norm2);
free(norm2);
}
if (norm3 != NULL) {
terrainAddVector(norm1,norm3);
free(norm3);
}
if (norm4 != NULL) {
terrainAddVector(norm1,norm4);
free(norm4);
}
terrainNormalize(norm1);
norm1[2] = - norm1[2];
for (k = 0; k< 3; k++)
{
terrainNormals[3*(i*width + j) + k] = norm1[k];
if((3*(i*width + j) + k) >= width *length*3)
{
std::cout<<"\nfunc:terrainComputeNormals() This can cause a heap corruption !!!";
std::cout<<"\nvalue is: "<<3*(i*width + j) + k;
}
}
free(norm1);
}
}
