Merge lp:~widelands-dev/widelands/rotate_terrains into lp:widelands

[SirVer]

Fixes an error in converting from pixel space to opengl space which flipped all textures vertically when drawn on screen.

A one byte fix for the flipped terrains.

[bunnybot (widelandsofficial)]

Hi, I am bunnybot (https://github.com/widelands/bunnybot).

I am keeping the source branch lp:~widelands-dev/widelands/rotate_terrains mirrored to https://github.com/widelands/widelands/tree/_widelands_dev_widelands_rotate_terrains

You can give me commands by starting a line with @bunnybot <command>. I understand:
 merge: Merges the source branch into the target branch, closing the merge proposal. I will use the proposed commit message if it is set.

[bunnybot (widelandsofficial)]

Travis build 326 has changed state to: passed. Details: https://travis-ci.org/widelands/widelands/builds/103784662.

[kaputtnik (franku)]

Wonderful :-)

Such a small change... I would suggest to have a comment in there describing why x isn't negative but y is.

review: Approve

[SirVer (sirver)]

Added a comment.

Thanks for testing and code review!

@bunnybot merge

=== modified file 'src/graphic/game_renderer.cc'
--- src/graphic/game_renderer.cc	2016-01-10 11:36:05 +0000
+++ src/graphic/game_renderer.cc	2016-01-21 21:11:01 +0000
@@ -187,8 +187,12 @@
 			map.normalize_coords(coords);
 			const FCoords& fcoords = map.get_fcoords(coords);
 
+			// Texture coordinates for pseudo random tiling of terrain and road
+			// graphics. Since screen space X increases top-to-bottom and OpenGL
+			// increases bottom-to-top we flip the y coordinate to not have
+			// terrains and road graphics vertically mirrorerd.
 			f.texture_x = float(x) / kTextureSideLength;
-			f.texture_y = float(y) / kTextureSideLength;
+			f.texture_y = -float(y) / kTextureSideLength;
 
 			f.gl_x = f.pixel_x = x + surface_offset.x;
 			f.gl_y = f.pixel_y = y + surface_offset.y - fcoords.field->get_height() * HEIGHT_FACTOR;