Improve the spot shadow computation.
Get rid of compuation of the intersection for penumbra and convex hull for umbra.
Use simple circle / normal to compute the penumbra and simple intersection for umbra.
The new way could be 2x to 4x faster from rectangle to round shape.
And this part is roughly half of the shadow computation, or 2/3 of spot shadow
computation.
This improve the spot shadow spikeness too.
b/16712006
b/14976551
Change-Id: I02911784868731369efa73f76fc915bc08248600
diff --git a/libs/hwui/ShadowTessellator.cpp b/libs/hwui/ShadowTessellator.cpp
index e71439d..6cff815 100644
--- a/libs/hwui/ShadowTessellator.cpp
+++ b/libs/hwui/ShadowTessellator.cpp
@@ -29,11 +29,6 @@
namespace android {
namespace uirenderer {
-template<typename T>
-static inline T max(T a, T b) {
- return a > b ? a : b;
-}
-
void ShadowTessellator::tessellateAmbientShadow(bool isCasterOpaque,
const Vector3* casterPolygon, int casterVertexCount,
const Vector3& centroid3d, const Rect& casterBounds,
@@ -66,7 +61,7 @@
}
void ShadowTessellator::tessellateSpotShadow(bool isCasterOpaque,
- const Vector3* casterPolygon, int casterVertexCount,
+ const Vector3* casterPolygon, int casterVertexCount, const Vector3& casterCentroid,
const mat4& receiverTransform, const Vector3& lightCenter, int lightRadius,
const Rect& casterBounds, const Rect& localClip, VertexBuffer& shadowVertexBuffer) {
ATRACE_CALL();
@@ -109,9 +104,9 @@
return;
}
- SpotShadow::createSpotShadow(isCasterOpaque,
- casterPolygon, casterVertexCount, adjustedLightCenter, lightRadius,
- lightVertexCount, shadowVertexBuffer);
+ SpotShadow::createSpotShadow(isCasterOpaque, adjustedLightCenter, lightRadius,
+ casterPolygon, casterVertexCount, casterCentroid, shadowVertexBuffer);
+
#if DEBUG_SHADOW
if(shadowVertexBuffer.getVertexCount() <= 0) {
ALOGD("Spot shadow generation failed %d", shadowVertexBuffer.getVertexCount());
@@ -180,6 +175,18 @@
return centroid;
}
+// Make sure p1 -> p2 is going CW around the poly.
+Vector2 ShadowTessellator::calculateNormal(const Vector2& p1, const Vector2& p2) {
+ Vector2 result = p2 - p1;
+ if (result.x != 0 || result.y != 0) {
+ result.normalize();
+ // Calculate the normal , which is CCW 90 rotate to the delta.
+ float tempy = result.y;
+ result.y = result.x;
+ result.x = -tempy;
+ }
+ return result;
+}
/**
* Test whether the polygon is order in clockwise.
*