diff options
| -rw-r--r-- | source/fitz/draw-paint.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/source/fitz/draw-paint.c b/source/fitz/draw-paint.c index e86c3b71..7de650ab 100644 --- a/source/fitz/draw-paint.c +++ b/source/fitz/draw-paint.c @@ -16,7 +16,7 @@ We take the following as definitions: The general PorterDuff blending equation is: - Blend Z = X op Y cz = Fx.cx + Fy. cy where Fx and Fy depend on op + Blend Z = X op Y cz = Fx.cx + Fy.cy where Fx and Fy depend on op The two operations we use in this file are: '(X in Y) over Z' and 'S over Z'. The definitions of the 'over' and 'in' operations are as @@ -59,7 +59,7 @@ Non Pre-multiplied case: Cr.ar = Fs.Cs.as + Fz.Cz.az (where Fs = 1, Fz = 1-as) = Cs.as + (1-as).Cz.az = Cx.ax.ay + Cz.az.(1-ax.ay) - Cr = (Cx.ax.ay + Cz.az.(1-ax.ay))/(ax.ay + az.(1-ax-ay)) + Cr = (Cx.ax.ay + Cz.az.(1-ax.ay))/(ax.ay + az.(1-ax.ay)) Much more complex, it seems. However, if we could restrict ourselves to the case where we were always plotting onto an opaque background (i.e. |