michael/pathfinder
michael
/
pathfinder
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Fixes #51 by introducing a variable for an early return boolean. 

This works around a bug in the macOS Nvidia shader compiler
in 2014 rMBPs.
This commit is contained in:
Tristan Hume 2017-12-05 21:09:58 -05:00
parent d0d08816b9
commit dd934211af
1 changed files with 5 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
shaders/gles2/common.inc.glsl
View File

@ -358,10 +358,6 @@ vec4 clipLineToPixelRow(vec2 p0, vec2 dP, float pixelCenterY, out float outPixel
return vec4(p0 + dP * tY.x, dP * (tY.y - tY.x)); return vec4(p0 + dP * tY.x, dP * (tY.y - tY.x));
} }
bool lineDoesNotPassThroughPixel(vec2 t) {
return t.x >= t.y;
}
/// Computes the area of the polygon covering the pixel with the given boundaries. /// Computes the area of the polygon covering the pixel with the given boundaries.
/// ///
/// The line must run left-to-right and must already be clipped to the left and right sides of the /// The line must run left-to-right and must already be clipped to the left and right sides of the
@ -383,7 +379,11 @@ float computeCoverage(vec2 p0X, vec2 dPX, float pixelCenterY, float winding) {
// //
// This should be worth a branch because it's very common for fragment blocks to all hit this // This should be worth a branch because it's very common for fragment blocks to all hit this
// path. // path.
if (isNearZero(dP.x) && isNearZero(dP.y)) //
// The variable is required to work around a bug in the macOS Nvidia drivers.
// Without moving the condition in a variable, the early return is ignored. See #51.
bool lineDoesNotPassThroughPixel = isNearZero(dP.x) && isNearZero(dP.y);
if (lineDoesNotPassThroughPixel)
return p0X.y < pixelTop ? winding * dPX.x : 0.0; return p0X.y < pixelTop ? winding * dPX.x : 0.0;
// Calculate points A0-A2. // Calculate points A0-A2.