void DynamicSkyLight::SetLightParams(float4 newLightDir, float startAngle, float orbitTime) {
newLightDir.ANormalize();
sunStartAngle = PI + startAngle; //FIXME WHY +PI?
sunOrbitTime = orbitTime;
initialSunAngle = GetRadFromXY(newLightDir.x, newLightDir.z);
//FIXME This function really really needs comments about what it does!
if (newLightDir.w == FLT_MAX) {
// old: newLightDir is position where sun reaches highest altitude
const float sunLen = newLightDir.Length2D();
const float sunAzimuth = (sunLen <= 0.001f) ? PI / 2.0f : atan(newLightDir.y / sunLen);
const float sunHeight = tan(sunAzimuth - 0.001f);
float3 v1(cos(initialSunAngle), sunHeight, sin(initialSunAngle));
v1.ANormalize();
if (v1.y <= orbitMinSunHeight) {
newLightDir = UpVector;
sunOrbitHeight = v1.y;
sunOrbitRad = sqrt(1.0f - sunOrbitHeight * sunOrbitHeight);
} else {
float3 v2(cos(initialSunAngle + PI), orbitMinSunHeight, sin(initialSunAngle + PI));
v2.ANormalize();
float3 v3 = v2 - v1;
sunOrbitRad = v3.Length() / 2.0f;
v3.ANormalize();
float3 v4 = (v3.cross(UpVector)).ANormalize();
float3 v5 = (v3.cross(v4)).ANormalize();
if (v5.y < 0.0f)
v5 = -v5;
newLightDir = v5;
sunOrbitHeight = v5.dot(v1);
}
} else {
// new: newLightDir is center position of orbit, and newLightDir.w is orbit height
sunOrbitHeight = std::max(-1.0f, std::min(newLightDir.w, 1.0f));
sunOrbitRad = sqrt(1.0f - sunOrbitHeight * sunOrbitHeight);
}
sunRotation.LoadIdentity();
sunRotation.SetUpVector(newLightDir);
const float4& peakDir = CalculateSunPos(0.0f);
const float peakElev = std::max(0.01f, peakDir.y);
shadowDensityFactor = 1.0f / peakElev;
SetLightDir(CalculateSunPos(sunStartAngle).ANormalize());
}
void CGlobalRendering::UpdateSunParams(float4 newSunDir, float startAngle, float orbitTime, bool iscompat) {
newSunDir.ANormalize();
sunStartAngle = startAngle;
sunOrbitTime = orbitTime;
initialSunAngle = fastmath::coords2angle(newSunDir.x, newSunDir.z);
if(iscompat) { // backwards compatible: sunDir is position where sun reaches highest altitude
float sunLen = newSunDir.Length2D();
float sunAzimuth = (sunLen <= 0.001f) ? PI / 2.0f : atan(newSunDir.y / sunLen);
float sunHeight = tan(sunAzimuth - 0.001f);
float orbitMinSunHeight = 0.1f; // the lowest sun altitude for an auto generated orbit
float3 v1(cos(initialSunAngle), sunHeight, sin(initialSunAngle));
v1.ANormalize();
if(v1.y <= orbitMinSunHeight) {
newSunDir = float3(0.0f, 1.0f, 0.0f);
sunOrbitHeight = v1.y;
sunOrbitRad = sqrt(1.0f - sunOrbitHeight * sunOrbitHeight);
}
else {
float3 v2(cos(initialSunAngle + PI), orbitMinSunHeight, sin(initialSunAngle + PI));
v2.ANormalize();
float3 v3 = v2 - v1;
sunOrbitRad = v3.Length() / 2.0f;
v3.ANormalize();
float3 v4 = v3.cross(float3(0.0f, 1.0f, 0.0f));
v4.ANormalize();
float3 v5 = v3.cross(v4);
v5.ANormalize();
if(v5.y < 0)
v5 = -v5;
newSunDir = v5;
sunOrbitHeight = v5.dot(v1);
}
}
else { // new: sunDir is center position of orbit, and sunDir.w is orbit height
sunOrbitHeight = std::max(-1.0f, std::min(newSunDir.w, 1.0f));
sunOrbitRad = sqrt(1.0f - sunOrbitHeight * sunOrbitHeight);
}
sunRotation.LoadIdentity();
sunRotation.SetUpVector(newSunDir);
float4 peakSunDir = CalculateSunDir(0.0f);
shadowDensityFactor = 1.0f / std::max(0.01f, peakSunDir.y);
UpdateSun(true);
}
