Update shadow render code to use lookup texture
Optimizes performance on low end devices by avoiding exp() in the
fragment shader and lowering the precision of the shadow attributes
used in the shaders.
Test: adb shell su root dumpsys SurfaceFlinger --timestats -dump -maxlayers 0 on wembley
Test: atest SurfaceFlinger_test librenderengine_test
Test: shadows still look like shadows
Change-Id: I0e6e35a2f4f2d31b3126438ebb8b34d92a7d98c0
diff --git a/libs/renderengine/gl/GLSkiaShadowPort.h b/libs/renderengine/gl/GLSkiaShadowPort.h
index e7d1861..912c8bb 100644
--- a/libs/renderengine/gl/GLSkiaShadowPort.h
+++ b/libs/renderengine/gl/GLSkiaShadowPort.h
@@ -17,13 +17,11 @@
#pragma once
#include <math/vec4.h>
+#include <renderengine/Mesh.h>
#include <ui/Rect.h>
namespace android {
namespace renderengine {
-
-class Mesh;
-
namespace gl {
/**
@@ -79,6 +77,20 @@
void fillIndicesForGeometry(const Geometry& shadowGeometry, int indexCount,
int startingVertexOffset, uint16_t* indices);
+/**
+ * Maps shadow geometry 'alpha' varying (1 for darkest, 0 for transparent) to
+ * darkness at that spot. Values are determined by an exponential falloff
+ * function provided by UX.
+ *
+ * The texture is used for quick lookup in theshadow shader.
+ *
+ * textureData - filled with shadow texture data that needs to be at least of
+ * size textureWidth
+ *
+ * textureWidth - width of the texture, height is always 1
+ */
+void fillShadowTextureData(uint8_t* textureData, size_t textureWidth);
+
} // namespace gl
} // namespace renderengine
} // namespace android