size_t TextureBuffer::bufferSizeTexels() const
{
if (texelSize() == 0)
LITE3D_THROW(getName() << " unsupported texture buffer format");
return bufferSizeBytes() / texelSize();
}
void Light::SetupShadowViews(Camera* mainCamera, Vector<AutoPtr<ShadowView> >& shadowViews, size_t& useIndex)
{
size_t numViews = NumShadowViews();
if (!numViews)
return;
if (shadowViews.Size() < useIndex + numViews)
shadowViews.Resize(useIndex + numViews);
int numVerticalSplits = (lightType == LIGHT_POINT || (lightType == LIGHT_DIRECTIONAL && NumShadowSplits() > 2)) ? 2 : 1;
int actualShadowMapSize = shadowRect.Height() / numVerticalSplits;
for (size_t i = 0; i < numViews; ++i)
{
if (!shadowViews[useIndex + i])
shadowViews[useIndex + i] = new ShadowView();
ShadowView* view = shadowViews[useIndex + i].Get();
view->Clear();
view->light = this;
Camera& shadowCamera = view->shadowCamera;
switch (lightType)
{
case LIGHT_DIRECTIONAL:
{
IntVector2 topLeft(shadowRect.left, shadowRect.top);
if (i & 1)
topLeft.x += actualShadowMapSize;
if (i & 2)
topLeft.y += actualShadowMapSize;
view->viewport = IntRect(topLeft.x, topLeft.y, topLeft.x + actualShadowMapSize, topLeft.y + actualShadowMapSize);
float splitStart = Max(mainCamera->NearClip(), (i == 0) ? 0.0f : ShadowSplit(i - 1));
float splitEnd = Min(mainCamera->FarClip(), ShadowSplit(i));
float extrusionDistance = mainCamera->FarClip();
// Calculate initial position & rotation
shadowCamera.SetTransform(mainCamera->WorldPosition() - extrusionDistance * WorldDirection(), WorldRotation());
// Calculate main camera shadowed frustum in light's view space
Frustum splitFrustum = mainCamera->WorldSplitFrustum(splitStart, splitEnd);
const Matrix3x4& lightView = shadowCamera.ViewMatrix();
Frustum lightViewFrustum = splitFrustum.Transformed(lightView);
// Fit the frustum inside a bounding box
BoundingBox shadowBox;
shadowBox.Define(lightViewFrustum);
// If shadow camera is far away from the frustum, can bring it closer for better depth precision
/// \todo The minimum distance is somewhat arbitrary
float minDistance = mainCamera->FarClip() * 0.25f;
if (shadowBox.min.z > minDistance)
{
float move = shadowBox.min.z - minDistance;
shadowCamera.Translate(Vector3(0.0f, 0.f, move));
shadowBox.min.z -= move,
shadowBox.max.z -= move;
}
shadowCamera.SetOrthographic(true);
shadowCamera.SetFarClip(shadowBox.max.z);
Vector3 center = shadowBox.Center();
Vector3 size = shadowBox.Size();
shadowCamera.SetOrthoSize(Vector2(size.x, size.y));
shadowCamera.SetZoom(1.0f);
// Center shadow camera to the view space bounding box
Vector3 pos(shadowCamera.WorldPosition());
Quaternion rot(shadowCamera.WorldRotation());
Vector3 adjust(center.x, center.y, 0.0f);
shadowCamera.Translate(rot * adjust, TS_WORLD);
// Snap to whole texels
{
Vector3 viewPos(rot.Inverse() * shadowCamera.WorldPosition());
float invSize = 1.0f / actualShadowMapSize;
Vector2 texelSize(size.x * invSize, size.y * invSize);
Vector3 snap(-fmodf(viewPos.x, texelSize.x), -fmodf(viewPos.y, texelSize.y), 0.0f);
shadowCamera.Translate(rot * snap, TS_WORLD);
}
}
break;
case LIGHT_POINT:
{
static const Quaternion pointLightFaceRotations[] = {
Quaternion(0.0f, 90.0f, 0.0f),
Quaternion(0.0f, -90.0f, 0.0f),
Quaternion(-90.0f, 0.0f, 0.0f),
Quaternion(90.0f, 0.0f, 0.0f),
Quaternion(0.0f, 0.0f, 0.0f),
Quaternion(0.0f, 180.0f, 0.0f)
};
IntVector2 topLeft(shadowRect.left, shadowRect.top);
if (i & 1)
topLeft.y += actualShadowMapSize;
topLeft.x += ((unsigned)i >> 1) * actualShadowMapSize;
view->viewport = IntRect(topLeft.x, topLeft.y, topLeft.x + actualShadowMapSize, topLeft.y + actualShadowMapSize);
shadowCamera.SetTransform(WorldPosition(), pointLightFaceRotations[i]);
shadowCamera.SetFov(90.0f);
// Adjust zoom to avoid edge sampling artifacts (there is a matching adjustment in the shadow sampling)
shadowCamera.SetZoom(0.99f);
shadowCamera.SetFarClip(Range());
shadowCamera.SetNearClip(Range() * 0.01f);
shadowCamera.SetOrthographic(false);
shadowCamera.SetAspectRatio(1.0f);
}
break;
case LIGHT_SPOT:
view->viewport = shadowRect;
shadowCamera.SetTransform(WorldPosition(), WorldRotation());
shadowCamera.SetFov(fov);
shadowCamera.SetZoom(1.0f);
shadowCamera.SetFarClip(Range());
shadowCamera.SetNearClip(Range() * 0.01f);
shadowCamera.SetOrthographic(false);
shadowCamera.SetAspectRatio(1.0f);
break;
}
}
// Setup shadow matrices now as camera positions have been finalized
if (lightType != LIGHT_POINT)
{
shadowMatrices.Resize(numViews);
for (size_t i = 0; i < numViews; ++i)
{
ShadowView* view = shadowViews[useIndex + i].Get();
Camera& shadowCamera = view->shadowCamera;
float width = (float)shadowMap->Width();
float height = (float)shadowMap->Height();
Vector3 offset((float)view->viewport.left / width, (float)view->viewport.top / height, 0.0f);
Vector3 scale(0.5f * (float)view->viewport.Width() / width, 0.5f * (float)view->viewport.Height() / height, 1.0f);
offset.x += scale.x;
offset.y += scale.y;
scale.y = -scale.y;
// OpenGL has different depth range
#ifdef TURSO3D_OPENGL
offset.z = 0.5f;
scale.z = 0.5f;
#endif
Matrix4 texAdjust(Matrix4::IDENTITY);
texAdjust.SetTranslation(offset);
texAdjust.SetScale(scale);
shadowMatrices[i] = texAdjust * shadowCamera.ProjectionMatrix() * shadowCamera.ViewMatrix();
}
}
else
{
// Point lights use an extra constant instead
shadowMatrices.Clear();
Vector2 textureSize((float)shadowMap->Width(), (float)shadowMap->Height());
pointShadowParameters = Vector4(actualShadowMapSize / textureSize.x, actualShadowMapSize / textureSize.y,
(float)shadowRect.left / textureSize.x, (float)shadowRect.top / textureSize.y);
}
// Calculate shadow mapping constants
Camera& shadowCamera = shadowViews[useIndex]->shadowCamera;
float nearClip = shadowCamera.NearClip();
float farClip = shadowCamera.FarClip();
float q = farClip / (farClip - nearClip);
float r = -q * nearClip;
shadowParameters = Vector4(0.5f / (float)shadowMap->Width(), 0.5f / (float)shadowMap->Height(), q, r);
useIndex += numViews;
}
