Fix various hw-accelerated line/point bugs
All accelerated lines are now rendered as quads. Hairlines used to
be rendered as GL_LINES, but these lines don't render the same as our
non-accelerated lines, so we're using quads for everything. Also, fixed
a bug in the way that we were offsetting quads (and not offseting points)
to ensure that our lines/points actuall start on the same pixels as
Skia's.
Change-Id: I51b923cc08a9858444c430ba07bc8aa0c83cbe6a
diff --git a/libs/hwui/Program.cpp b/libs/hwui/Program.cpp
index 2187f24..972dd87 100644
--- a/libs/hwui/Program.cpp
+++ b/libs/hwui/Program.cpp
@@ -124,8 +124,15 @@
}
void Program::set(const mat4& projectionMatrix, const mat4& modelViewMatrix,
- const mat4& transformMatrix) {
+ const mat4& transformMatrix, bool offset) {
mat4 t(projectionMatrix);
+ if (offset) {
+ // offset screenspace xy by an amount that compensates for typical precision issues
+ // in GPU hardware that tends to paint hor/vert lines in pixels shifted 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.
+ t.translate(.375, .375, 0);
+ }
t.multiply(transformMatrix);
t.multiply(modelViewMatrix);