[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [43876] trunk/blender/source: Fix for aliased fonts in the game engine.

[Alex Fraser]

Revision: 43876
          http://projects.blender.org/scm/viewvc.php?view=rev&root=bf-blender&revision=43876
Author:   z0r
Date:     2012-02-04 01:51:59 +0000 (Sat, 04 Feb 2012)
Log Message:
-----------
Fix for aliased fonts in the game engine.
 - Mipmaps are generated in BLF when drawing text in-game. In that case, padding around each glyph is increased to prevent bleeding.
 - Texture filtering is turned on for in-game text.
 - All glyphs are now "twisted": the leading edge is brought a small distance forward, to prevent z-fighting in overlapping (kerned) glyphs. This happens both in the game engine and the rest of the UI, but should have no effect in the UI due to Z-compression in the clipping matrix.
Reviewed and approved by bdiego; see patch [#29882] in the tracker. Tested by dfelinto.

Modified Paths:
--------------
    trunk/blender/source/blender/blenfont/BLF_api.h
    trunk/blender/source/blender/blenfont/intern/blf_glyph.c
    trunk/blender/source/gameengine/BlenderRoutines/KX_BlenderGL.cpp
    trunk/blender/source/gameengine/GamePlayer/common/GPC_RenderTools.cpp

Modified: trunk/blender/source/blender/blenfont/BLF_api.h
===================================================================
--- trunk/blender/source/blender/blenfont/BLF_api.h	2012-02-04 00:36:55 UTC (rev 43875)
+++ trunk/blender/source/blender/blenfont/BLF_api.h	2012-02-04 01:51:59 UTC (rev 43876)
@@ -197,6 +197,7 @@
 #define BLF_KERNING_DEFAULT (1<<3)
 #define BLF_MATRIX (1<<4)
 #define BLF_ASPECT (1<<5)
+#define BLF_TEXFILTER (1<<6)
 
 #define BLF_DRAW_STR_DUMMY_MAX 1024
 

Modified: trunk/blender/source/blender/blenfont/intern/blf_glyph.c
===================================================================
--- trunk/blender/source/blender/blenfont/intern/blf_glyph.c	2012-02-04 00:36:55 UTC (rev 43875)
+++ trunk/blender/source/blender/blenfont/intern/blf_glyph.c	2012-02-04 01:51:59 UTC (rev 43876)
@@ -54,6 +54,8 @@
 #include "blf_internal_types.h"
 #include "blf_internal.h"
 
+#define _BLF_PADDING 3
+#define _BLF_MIPMAP_LEVELS 3
 
 GlyphCacheBLF *blf_glyph_cache_find(FontBLF *font, int size, int dpi)
 {
@@ -87,7 +89,11 @@
 	gc->cur_tex= -1;
 	gc->x_offs= 0;
 	gc->y_offs= 0;
-	gc->pad= 3;
+	/* Increase padding for each mipmap level: 0->3, 1->4, 2->6, 3->10, ... */
+	if (font->flags & BLF_TEXFILTER)
+		gc->pad= pow(2, _BLF_MIPMAP_LEVELS) + 2;
+	else
+		gc->pad= _BLF_PADDING;
 
 	gc->num_glyphs= font->face->num_glyphs;
 	gc->rem_glyphs= font->face->num_glyphs;
@@ -296,13 +302,17 @@
 
 static void blf_texture_draw(float uv[2][2], float dx, float y1, float dx1, float y2)
 {
-	
+	/* When a string is being rendered as individual glyphs (as in the game
+	 * engine), the leading edge needs to be raised a fraction to prevent
+	 * z-fighting for kerned characters. - z0r */
+	float twist = (dx1 - dx) * 0.0002;
+
 	glBegin(GL_QUADS);
 	glTexCoord2f(uv[0][0], uv[0][1]);
-	glVertex2f(dx, y1);
+	glVertex3f(dx, y1, twist);
 	
 	glTexCoord2f(uv[0][0], uv[1][1]);
-	glVertex2f(dx, y2);
+	glVertex3f(dx, y2, twist);
 	
 	glTexCoord2f(uv[1][0], uv[1][1]);
 	glVertex2f(dx1, y2);
@@ -405,6 +415,15 @@
 
 		glBindTexture(GL_TEXTURE_2D, g->tex);
 		glTexSubImage2D(GL_TEXTURE_2D, 0, g->xoff, g->yoff, g->width, g->height, GL_ALPHA, GL_UNSIGNED_BYTE, g->bitmap);
+		if (font->flags & BLF_TEXFILTER) {
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL,
+					_BLF_MIPMAP_LEVELS);
+			glGenerateMipmap(GL_TEXTURE_2D);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
+					GL_LINEAR_MIPMAP_LINEAR);
+		}
 		glPopClientAttrib();
 
 		g->uv[0][0]= ((float)g->xoff) / ((float)gc->p2_width);

Modified: trunk/blender/source/gameengine/BlenderRoutines/KX_BlenderGL.cpp
===================================================================
--- trunk/blender/source/gameengine/BlenderRoutines/KX_BlenderGL.cpp	2012-02-04 00:36:55 UTC (rev 43875)
+++ trunk/blender/source/gameengine/BlenderRoutines/KX_BlenderGL.cpp	2012-02-04 01:51:59 UTC (rev 43876)
@@ -136,8 +136,8 @@
 	/* the actual drawing */
 	glColor4fv(color);
 
+	BLF_enable(fontid, BLF_MATRIX|BLF_ASPECT|BLF_TEXFILTER);
 	/* multiply the text matrix by the object matrix */
-	BLF_enable(fontid, BLF_MATRIX|BLF_ASPECT);
 	BLF_matrix(fontid, mat);
 
 	/* aspect is the inverse scale that allows you to increase */
@@ -149,7 +149,7 @@
 	BLF_position(fontid, 0, 0, 0);
 	BLF_draw(fontid, (char *)text, 65535);
 
-	BLF_disable(fontid, BLF_MATRIX|BLF_ASPECT);
+	BLF_disable(fontid, BLF_MATRIX|BLF_ASPECT|BLF_TEXFILTER);
 }
 
 void BL_print_gamedebug_line(const char* text, int xco, int yco, int width, int height)

Modified: trunk/blender/source/gameengine/GamePlayer/common/GPC_RenderTools.cpp
===================================================================
--- trunk/blender/source/gameengine/GamePlayer/common/GPC_RenderTools.cpp	2012-02-04 00:36:55 UTC (rev 43875)
+++ trunk/blender/source/gameengine/GamePlayer/common/GPC_RenderTools.cpp	2012-02-04 01:51:59 UTC (rev 43876)
@@ -294,8 +294,8 @@
 	/* the actual drawing */
 	glColor3fv(color);
  
+	BLF_enable(fontid, BLF_MATRIX|BLF_ASPECT|BLF_TEXFILTER);
 	/* multiply the text matrix by the object matrix */
-	BLF_enable(fontid, BLF_MATRIX|BLF_ASPECT);
 	BLF_matrix(fontid, mat);
 
 	/* aspect is the inverse scale that allows you to increase */
@@ -307,7 +307,7 @@
 	BLF_position(fontid, 0, 0, 0);
 	BLF_draw(fontid, text, 65535);
 
-	BLF_disable(fontid, BLF_MATRIX|BLF_ASPECT);
+	BLF_disable(fontid, BLF_MATRIX|BLF_ASPECT|BLF_TEXFILTER);
 	glEnable(GL_DEPTH_TEST);
 }