Merge lp:~tino79/widelands/fix_screenshots into lp:widelands

[Tino]

When saving a screenshot don't use alpha channel

[GunChleoc (gunchleoc)]

That fixes it :)

review: Approve

[SirVer (sirver)]

Unfortunately this fix introduces other bugs. The same function is used to save all surfaces to files in Widelands, for example also the custom graphics in scenarios that might contain RGBA data, so this fix is not correct.

My suggested fix: introduce a enum class Format { RGB, RGBA }; and take it as an extra parameter to the save_surface function and fix the call sites to use RGBA everywhere, but when saving screenshots.

review: Needs Fixing

=== modified file 'src/graphic/image_io.cc'
--- src/graphic/image_io.cc	2014-11-24 07:10:03 +0000
+++ src/graphic/image_io.cc	2014-11-28 18:44:33 +0000
@@ -104,7 +104,7 @@
 	             surface->width(),
 	             surface->height(),
 	             8,
-	             PNG_COLOR_TYPE_RGB_ALPHA,
+	             PNG_COLOR_TYPE_RGB,
 	             PNG_INTERLACE_NONE,
 	             PNG_COMPRESSION_TYPE_DEFAULT,
 	             PNG_FILTER_TYPE_DEFAULT);
@@ -114,7 +114,7 @@
 	{
 		const uint16_t surf_w = surface->width();
 		const uint16_t surf_h = surface->height();
-		const uint32_t row_size = 4 * surf_w;
+		const uint32_t row_size = 3 * surf_w;
 
 		std::unique_ptr<png_byte[]> row(new png_byte[row_size]);
 
@@ -127,10 +127,9 @@
 			for (uint32_t x = 0; x < surf_w; ++x) {
 				RGBAColor color;
 				color.set(fmt, surface->get_pixel(x, y));
-				row[4 * x] = color.r;
-				row[4 * x + 1] = color.g;
-				row[4 * x + 2] = color.b;
-				row[4 * x + 3] = color.a;
+				row[3 * x] = color.r;
+				row[3 * x + 1] = color.g;
+				row[3 * x + 2] = color.b;
 			}
 
 			png_write_row(png_ptr, row.get());