private int getEnvironmentMap(Vector3f normal, int[] inPixels, int width, int height) {
if (environmentMap != null) {
float angle = (float) Math.acos(-normal.y);
float x, y;
y = angle / ImageMath.PI;
if (y == 0.0f || y == 1.0f) x = 0.0f;
else {
float f = normal.x / (float) Math.sin(angle);
if (f > 1.0f) f = 1.0f;
else if (f < -1.0f) f = -1.0f;
x = (float) Math.acos(f) / ImageMath.PI;
}
// A bit of empirical scaling....
x = ImageMath.clamp(x * envWidth, 0, envWidth - 1);
y = ImageMath.clamp(y * envHeight, 0, envHeight - 1);
int ix = (int) x;
int iy = (int) y;
float xWeight = x - ix;
float yWeight = y - iy;
int i = envWidth * iy + ix;
int dx = ix == envWidth - 1 ? 0 : 1;
int dy = iy == envHeight - 1 ? 0 : envWidth;
return ImageMath.bilinearInterpolate(
xWeight,
yWeight,
envPixels[i],
envPixels[i + dx],
envPixels[i + dy],
envPixels[i + dx + dy]);
}
return 0;
}
private int getEnvironmentMapP(Vector3f normal, int[] inPixels, int width, int height) {
if (environmentMap != null) {
float x = 0.5f * (1 + normal.x);
float y = 0.5f * (1 + normal.y);
x = ImageMath.clamp(x * envWidth, 0, envWidth - 1);
y = ImageMath.clamp(y * envHeight, 0, envHeight - 1);
int ix = (int) x;
int iy = (int) y;
float xWeight = x - ix;
float yWeight = y - iy;
int i = envWidth * iy + ix;
int dx = ix == envWidth - 1 ? 0 : 1;
int dy = iy == envHeight - 1 ? 0 : envWidth;
return ImageMath.bilinearInterpolate(
xWeight,
yWeight,
envPixels[i],
envPixels[i + dx],
envPixels[i + dy],
envPixels[i + dx + dy]);
}
return 0;
}