am ce9ee16d: Merge "Conservatively estimate geometry bounds" into klp-dev
* commit 'ce9ee16d654a42f31d211c60708d7b23f17c1d8e':
Conservatively estimate geometry bounds
diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index 2066f69..89a82fd 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -1628,14 +1628,7 @@
Rect r(left, top, right, bottom);
currentTransform().mapRect(r);
-
- if (snapOut) {
- // snapOut is generally used to account for 1 pixel ramp (in window coordinates)
- // outside of the provided rect boundaries in tessellated AA geometry
- r.snapOutToPixelBoundaries();
- } else {
- r.snapToPixelBoundaries();
- }
+ r.snapGeometryToPixelBoundaries(snapOut);
Rect clipRect(*mSnapshot->clipRect);
clipRect.snapToPixelBoundaries();
diff --git a/libs/hwui/Program.cpp b/libs/hwui/Program.cpp
index 9e4670e..7814a01 100644
--- a/libs/hwui/Program.cpp
+++ b/libs/hwui/Program.cpp
@@ -20,6 +20,7 @@
#include <utils/Trace.h>
#include "Program.h"
+#include "Vertex.h"
namespace android {
namespace uirenderer {
@@ -172,7 +173,7 @@
// up and to the left.
// This offset value is based on an assumption that some hardware may use as
// little as 12.4 precision, so we offset by slightly more than 1/16.
- p.translate(.065, .065);
+ p.translate(Vertex::gGeometryFudgeFactor, Vertex::gGeometryFudgeFactor);
glUniformMatrix4fv(projection, 1, GL_FALSE, &p.data[0]);
}
mProjection = projectionMatrix;
diff --git a/libs/hwui/Rect.h b/libs/hwui/Rect.h
index 7605307..dabd8d4 100644
--- a/libs/hwui/Rect.h
+++ b/libs/hwui/Rect.h
@@ -21,6 +21,8 @@
#include <utils/Log.h>
+#include "Vertex.h"
+
namespace android {
namespace uirenderer {
@@ -171,17 +173,37 @@
}
/**
- * Similar to snapToPixelBoundaries, but used for AA geometry with a ramp perimeter.
+ * Similar to snapToPixelBoundaries, but estimates bounds conservatively to handle GL rounding
+ * errors.
*
- * We inset the data by a fudge factor of slightly over 1/16 (similar to when drawing non-AA
- * lines) before rounding out so that insignificant amounts of ramp geometry (esp. from rounding
- * errors) are ignored.
+ * This function should be used whenever estimating the damage rect of geometry already mapped
+ * into layer space.
*/
- void snapOutToPixelBoundaries() {
- left = floorf(left + 0.065f);
- top = floorf(top + 0.065f);
- right = ceilf(right - 0.065f);
- bottom = ceilf(bottom - 0.065f);
+ void snapGeometryToPixelBoundaries(bool snapOut) {
+ if (snapOut) {
+ /* For AA geometry with a ramp perimeter, don't snap by rounding - AA geometry will have
+ * a 0.5 pixel perimeter not accounted for in its bounds. Instead, snap by
+ * conservatively rounding out the bounds with floor/ceil.
+ *
+ * In order to avoid changing integer bounds with floor/ceil due to rounding errors
+ * inset the bounds first by the fudge factor. Very small fraction-of-a-pixel errors
+ * from this inset will only incur similarly small errors in output, due to transparency
+ * in extreme outside of the geometry.
+ */
+ left = floorf(left + Vertex::gGeometryFudgeFactor);
+ top = floorf(top + Vertex::gGeometryFudgeFactor);
+ right = ceilf(right - Vertex::gGeometryFudgeFactor);
+ bottom = ceilf(bottom - Vertex::gGeometryFudgeFactor);
+ } else {
+ /* For other geometry, we do the regular rounding in order to snap, but also outset the
+ * bounds by a fudge factor. This ensures that ambiguous geometry (e.g. a non-AA Rect
+ * with top left at (0.5, 0.5)) will err on the side of a larger damage rect.
+ */
+ left = floorf(left + 0.5f - Vertex::gGeometryFudgeFactor);
+ top = floorf(top + 0.5f - Vertex::gGeometryFudgeFactor);
+ right = floorf(right + 0.5f + Vertex::gGeometryFudgeFactor);
+ bottom = floorf(bottom + 0.5f + Vertex::gGeometryFudgeFactor);
+ }
}
void snapToPixelBoundaries() {
diff --git a/libs/hwui/Vertex.h b/libs/hwui/Vertex.h
index c06762f..790d4fc 100644
--- a/libs/hwui/Vertex.h
+++ b/libs/hwui/Vertex.h
@@ -26,6 +26,15 @@
* Simple structure to describe a vertex with a position and a texture.
*/
struct Vertex {
+ /**
+ * Fudge-factor used to disambiguate geometry pixel positioning.
+ *
+ * Used to offset lines and points to avoid ambiguous intersection with pixel centers (see
+ * Program::set()), and used to make geometry damage rect calculation conservative (see
+ * Rect::snapGeometryToPixelBoundaries())
+ */
+ static const float gGeometryFudgeFactor = 0.0656f;
+
float position[2];
static inline void set(Vertex* vertex, float x, float y) {