lib: only debug_warn in UNREACHABLE in paranoia builds - avoids lots of warnings in debug mode

cursor: fix definition of ALLOW_SYS_CURSOR and use DDS instead of PNG
ogl_tex: add ogl_tex_transform_to for convenience
tex: fix issue with transform code (might not flip image if it was DDS)
win: decompress cursor texture if it was DDS
renderer: use DDS instead of PNG for alpha maps

This was SVN commit r3148.

source/lib/lib.h

@@ -313,9 +313,12 @@ enum LibError
 
 // indicates a piece of code cannot be reached (e.g. because all
 // control paths before it end up returning). this is mostly for
-// human benefit, but it may also help optimization and warns in debug mode.
+// human benefit, but it may also help optimization and generates
+// warnings if reached in paranoia builds.
 #if MSC_VERSION
-# ifndef NDEBUG
+// .. note: we only enable this in paranoia builds because it
+//    causes "unreachable code" warnings (exactly what we want to avoid).
+# if CONFIG_PARANOIA
 #  define UNREACHABLE debug_warn("hit supposedly unreachable code");
 # else
 #  define UNREACHABLE __assume(0)

source/lib/res/graphics/cursor.cpp

@@ -7,7 +7,9 @@
 // cursors (Windows = more responsive, OpenGL = more consistent with what
 // the game sees)
 #if OS_WIN
-#define ALLOW_SYS_CURSOR 1
+# define ALLOW_SYS_CURSOR 1
+#else
+# define ALLOW_SYS_CURSOR 0
 #endif
 
 #include "lib/ogl.h"
@@ -121,7 +123,7 @@ static int Cursor_reload(Cursor* c, const char* name, Handle)
 	}
 
 	// load actual cursor
-	snprintf(filename, ARRAY_SIZE(filename), "art/textures/cursors/%s.png", name);
+	snprintf(filename, ARRAY_SIZE(filename), "art/textures/cursors/%s.dds", name);
 	// .. system cursor (2d, hardware accelerated)
 #if ALLOW_SYS_CURSOR
 	WARN_ERR(sys_cursor_load(filename, hotspotx, hotspoty, &c->sys_cursor));

source/lib/res/graphics/ogl_tex.cpp

@@ -957,3 +957,13 @@ int ogl_tex_transform(Handle ht, uint transforms)
 	int ret = tex_transform(&ot->t, transforms);
 	return ret;
 }
+
+
+// change the pixel format to that specified by <new_flags>.
+// (note: this is equivalent to ogl_tex_transform(ht, ht_flags^new_flags).
+int ogl_tex_transform_to(Handle ht, uint new_flags)
+{
+	H_DEREF(ht, OglTex, ot);
+	int ret = tex_transform_to(&ot->t, new_flags);
+	return ret;
+}

source/lib/res/graphics/ogl_tex.h

@@ -313,4 +313,8 @@ extern int ogl_tex_bind(Handle ht, uint unit = 0);
 // must be called before uploading (raises a warning if called afterwards).
 extern int ogl_tex_transform(Handle ht, uint flags);
 
+// change the pixel format to that specified by <new_flags>.
+// (note: this is equivalent to ogl_tex_transform(ht, ht_flags^new_flags).
+extern int ogl_tex_transform_to(Handle ht, uint new_flags);
+
 #endif	// #ifndef OGL_TEX_H__

source/lib/res/graphics/tex.cpp

@@ -532,19 +532,21 @@ TIMER_ACCRUE(tc_transform);
 	CHECK_TEX(t);
 
 	const uint target_flags = t->flags ^ transforms;
+	uint remaining_transforms;
 	for(;;)
 	{
+		remaining_transforms = target_flags ^ t->flags;
 		// we're finished (all required transforms have been done)
-		if(t->flags == target_flags)
+		if(remaining_transforms == 0)
 			return 0;
 
-		int ret = tex_codec_transform(t, transforms);
+		int ret = tex_codec_transform(t, remaining_transforms);
 		if(ret != 0)
 			break;
 	}
 
 	// last chance
-	CHECK_ERR(plain_transform(t, transforms));
+	CHECK_ERR(plain_transform(t, remaining_transforms));
 	return 0;
 }
 

source/lib/sysdep/win/win.cpp

@@ -561,8 +561,9 @@ int sys_cursor_load(const char* filename,
 	RETURN_ERR(tex_load(filename, &t));
 	uint w = t.w, h = t.h;
 
-	// convert to BGRA (required by CreateBitmap).
+	// convert to format required by CreateBitmap.
-	RETURN_ERR(tex_transform_to(&t, t.flags|TEX_BGR));
+	const uint flags = (t.flags | TEX_BGR) & ~TEX_DXT;
+	RETURN_ERR(tex_transform_to(&t, flags));
 	void* tex_bgra = tex_get_data(&t);
 
 	// MSDN says selecting this HBITMAP into a DC is slower since we use

source/renderer/Renderer.cpp

@@ -1453,20 +1453,20 @@ int CRenderer::LoadAlphaMaps()
 	PathPackage pp;
 	(void)pp_set_dir(&pp, "art/textures/terrain/alphamaps/special");
 	const char* fnames[NumAlphaMaps] = {
-		"blendcircle.png",
+		"blendcircle.dds",
-		"blendlshape.png",
+		"blendlshape.dds",
-		"blendedge.png",
+		"blendedge.dds",
-		"blendedgecorner.png",
+		"blendedgecorner.dds",
-		"blendedgetwocorners.png",
+		"blendedgetwocorners.dds",
-		"blendfourcorners.png",
+		"blendfourcorners.dds",
-		"blendtwooppositecorners.png",
+		"blendtwooppositecorners.dds",
-		"blendlshapecorner.png",
+		"blendlshapecorner.dds",
-		"blendtwocorners.png",
+		"blendtwocorners.dds",
-		"blendcorner.png",
+		"blendcorner.dds",
-		"blendtwoedges.png",
+		"blendtwoedges.dds",
-		"blendthreecorners.png",
+		"blendthreecorners.dds",
-		"blendushape.png",
+		"blendushape.dds",
-		"blendbad.png"
+		"blendbad.dds"
 	};
 	uint base = 0;	// texture width/height (see below)
 	// for convenience, we require all alpha maps to be of the same BPP
@@ -1480,6 +1480,13 @@ int CRenderer::LoadAlphaMaps()
 		textures[i] = ogl_tex_load(pp.path, RES_NO_CACHE);
 		RETURN_ERR(textures[i]);
 
+// quick hack: we require plain RGB(A) format, so convert to that.
+// ideally the texture would be in uncompressed form; then this wouldn't
+// be necessary.
+uint flags;
+ogl_tex_get_format(textures[i], &flags, 0);
+ogl_tex_transform_to(textures[i], flags & ~TEX_DXT);
+
 		// get its size and make sure they are all equal.
 		// (the packing algo assumes this)
 		uint this_width = 0, this_bpp = 0;	// fail-safe