From 31964a4ce7607404987374d6cc7c0d4b2f1a528a Mon Sep 17 00:00:00 2001
From: Andreas Eversberg <jolly@eversberg.eu>
Date: Fri, 15 Aug 2014 21:05:30 +0200
Subject: [PATCH] Show "unchanged color" as checkered pattern

Also do not show any gray fade on the palette for this special color.
---
 gui/image.c   | 15 +++++++++---
 gui/palette.c | 76 +++++++++++++++++++++++++++++++++--------------------------
 2 files changed, 55 insertions(+), 36 deletions(-)

diff --git a/gui/image.c b/gui/image.c
index 258a377..06e40c5 100644
--- a/gui/image.c
+++ b/gui/image.c
@@ -179,6 +179,7 @@ void draw_image(int x, int y, int w, int h)
 	int window_width, window_height, x_offset, y_offset;
 	gdk_drawable_get_size (draw, &window_width, &window_height);
 	double _r, _g, _b, _y, _u, _v, u_palette, v_palette;
+	int cr, cg, cb;
 	int _c, preview_asis = 0;
 
 	if (w < 0)
@@ -328,9 +329,17 @@ void draw_image(int x, int y, int w, int h)
 							compose[j*3+2] = 128;
 						}
 					} else {
-						compose[j*3] = mark_palette[c-1].r;
-						compose[j*3+1] = mark_palette[c-1].g;
-						compose[j*3+2] = mark_palette[c-1].b;
+						cr = mark_palette[c-1].r;
+						cg = mark_palette[c-1].g;
+						cb = mark_palette[c-1].b;
+						if (cr == 255 && cg == 255 && cb == 255) {
+							compose[j*3] = compose[j*3+1] = compose[j*3+2] = ((((i+y)>>3)&1) == (((j+x)>>3)&1)) ? 255 : 192;
+						} else
+						{
+							compose[j*3] = cr;
+							compose[j*3+1] = cg;
+							compose[j*3+2] = cb;
+						}
 					}
 				}
 			}
diff --git a/gui/palette.c b/gui/palette.c
index f02baa1..e6d2ee7 100644
--- a/gui/palette.c
+++ b/gui/palette.c
@@ -47,42 +47,52 @@ static GdkPixbuf *draw_pixpuf(int i)
 	pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE, 8, COLOR_WIDTH, COLOR_HEIGHT);
 	data = gdk_pixbuf_get_pixels(pixbuf);
 	rs = gdk_pixbuf_get_rowstride(pixbuf);
-	for (k = 0; k < COLOR_WIDTH; k++) {
-		/* we use height as horizontal size of original color area */
-		if (k >= COLOR_HEIGHT+3) {
-			y = (double)(k-COLOR_HEIGHT-3) / (double)((COLOR_WIDTH-COLOR_HEIGHT-3)-1);
-			y = (y - 0.5) * contrast + 0.5;
-			y += bright;
-			if (y < 0)
-				y = 0;
-			if (y > 1)
-				y = 1;
-			yuv2rgb_pixle(y, u, v, &r, &g, &b);
-			cr = r * 255.0F;
-			if (cr < 0)
-				cr = 0;
-			else if (cr > 255)
+	if (cr == 255 && cg == 255 && cb == 255) {
+		for (k = 0; k < COLOR_WIDTH; k++) {
+			for (j = 0; j < COLOR_HEIGHT; j++) {
+				data[j * rs + k * 3 + 0] = 255;
+				data[j * rs + k * 3 + 1] = 255;
+				data[j * rs + k * 3 + 2] = 255;
+			}
+		}
+	} else {
+		for (k = 0; k < COLOR_WIDTH; k++) {
+			/* we use height as horizontal size of original color area */
+			if (k >= COLOR_HEIGHT+3) {
+				y = (double)(k-COLOR_HEIGHT-3) / (double)((COLOR_WIDTH-COLOR_HEIGHT-3)-1);
+				y = (y - 0.5) * contrast + 0.5;
+				y += bright;
+				if (y < 0)
+					y = 0;
+				if (y > 1)
+					y = 1;
+				yuv2rgb_pixle(y, u, v, &r, &g, &b);
+				cr = r * 255.0F;
+				if (cr < 0)
+					cr = 0;
+				else if (cr > 255)
+					cr = 255;
+				cg = g * 255.0F;
+				if (cg < 0)
+					cg = 0;
+				else if (cg > 255)
+					cg = 255;
+				cb = b * 255.0F;
+				if (cb < 0)
+					cb = 0;
+				else if (cb > 255)
+					cb = 255;
+			} else
+			if (k >= COLOR_HEIGHT) {
 				cr = 255;
-			cg = g * 255.0F;
-			if (cg < 0)
-				cg = 0;
-			else if (cg > 255)
 				cg = 255;
-			cb = b * 255.0F;
-			if (cb < 0)
-				cb = 0;
-			else if (cb > 255)
 				cb = 255;
-		} else
-		if (k >= COLOR_HEIGHT) {
-			cr = 255;
-			cg = 255;
-			cb = 255;
-		}
-		for (j = 0; j < COLOR_HEIGHT; j++) {
-			data[j * rs + k * 3 + 0] = cr;
-			data[j * rs + k * 3 + 1] = cg;
-			data[j * rs + k * 3 + 2] = cb;
+			}
+			for (j = 0; j < COLOR_HEIGHT; j++) {
+				data[j * rs + k * 3 + 0] = cr;
+				data[j * rs + k * 3 + 1] = cg;
+				data[j * rs + k * 3 + 2] = cb;
+			}
 		}
 	}
 
-- 
2.13.6