- removed the Softpoly backend.

Its only relevant use case has been to use the software renderer on hardware not capable of OpenGL 3.3, but a large chunk of that can now be serviced with GLES.
In addition it has ceased further development and has not received any of the recent 2D render features which further reduces its viability.

src/common/rendering/r_thread.h

@@ -34,8 +34,6 @@
 // Use multiple threads when drawing
 EXTERN_CVAR(Int, r_multithreaded)
 
-class PolyTriangleThreadData;
-
 namespace swrenderer { class WallColumnDrawerArgs; }
 
 // Worker data for each thread executing drawer commands
@@ -64,8 +62,6 @@ public:
 	// Working buffer used by the tilted (sloped) span drawer
 	const uint8_t *tiltlighting[MAXWIDTH];
 
-	std::unique_ptr<PolyTriangleThreadData> poly;
-	
 	size_t debug_draw_pos = 0;
 
 	// Checks if a line is rendered by this thread