From: H.G. Muller <h.g.muller@hccnet.nl>
Date: Fri, 12 Oct 2012 12:42:26 +0000 (+0200)
Subject: Suppress anti-aliasing in -monoMode
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=c6dc3f6ed99ee75be391ff43360952370f7cb796;p=xboard.git

Suppress anti-aliasing in -monoMode

In the color-substitution code, always use bi-level alpha and color.
---

diff --git a/draw.c b/draw.c
index 2da2dd7..193f65c 100644
--- a/draw.c
+++ b/draw.c
@@ -311,6 +311,11 @@ ScaleOnePiece (int color, int piece)
 	buf[i*stride + j] = c & 0xFF000000; // alpha channel is kept at same opacity
 	buf[i*stride + j] += ((int)(f*(p&0xFF0000)) & 0xFF0000) + ((int)(f*(p&0xFF00)) & 0xFF00) + (int)(f*(p&0xFF)); // add desired fraction of new color
 	if(color) buf[i*stride + j] += r | r << 8 | r << 16; // details on black pieces get their weight added in pure white
+	if(appData.monoMode) {
+	    if(a < 64) buf[i*stride + j] = 0; // if not opaque enough, totally transparent
+	    else if(2*r < a) buf[i*stride + j] = 0xFF000000; // if not light enough, totally black
+            else buf[i*stride + j] = 0xFFFFFFFF; // otherwise white
+	}
     }
     cairo_surface_mark_dirty(cs);
   }