[Gzz-commits] manuscripts/AGPU Makefile fonts.txt

[Tuomas J. Lukka]

CVSROOT:        /cvsroot/gzz
Module name:    manuscripts
Changes by:     Tuomas J. Lukka <address@hidden>        03/04/14 15:39:51

Modified files:
        AGPU           : Makefile fonts.txt 

Log message:
        Chop off distance filtering

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/manuscripts/AGPU/Makefile.diff?tr1=1.4&tr2=1.5&r1=text&r2=text
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/manuscripts/AGPU/fonts.txt.diff?tr1=1.11&tr2=1.12&r1=text&r2=text

Patches:
Index: manuscripts/AGPU/Makefile
diff -u manuscripts/AGPU/Makefile:1.4 manuscripts/AGPU/Makefile:1.5
--- manuscripts/AGPU/Makefile:1.4       Mon Apr 14 15:30:29 2003
+++ manuscripts/AGPU/Makefile   Mon Apr 14 15:39:51 2003
@@ -22,5 +22,5 @@
        ln -fs paper_buoyoing2.png paper7.png
 
        ln -fs fonts_trilinear.png fonts1.png
-       ln -fs fonts_distfilter.png fonts2.png
-       ln -fs fonts_subpixel.png fonts3.png
+       ln -fs fonts_subpixel.png fonts2.png
+       rm -f fonts3.png
Index: manuscripts/AGPU/fonts.txt
diff -u manuscripts/AGPU/fonts.txt:1.11 manuscripts/AGPU/fonts.txt:1.12
--- manuscripts/AGPU/fonts.txt:1.11     Mon Apr 14 15:30:29 2003
+++ manuscripts/AGPU/fonts.txt  Mon Apr 14 15:39:51 2003
@@ -1,42 +1,6 @@
-This proposal is a bit long - feel free to take just the parts
-you're interested in.
 
-Legible text using the flexibility of modern GPUs
-=================================================
-
-We present several implementations of well-known algorithms
-and one novel algorithm for using the GPU to 
-enhance the appearance of text. Feel free to accept only one or the other.
-
-1. Sharpening text
-------------------
-
-In our research on flexible hypertextual user interfaces, we often
-want to use rotated, scaled, sheared or curving text.  Because normal
-windowing systems (such as X) do not provide for this, we have turned to
-OpenGL. However, as is well known to the graphics community, trilinear
-filtering does Horrible Things to text (but bilinear / nearest filtering
-are even worse): the text, especially at small font sizes, is often too
-blurred to read comfortably.
-
-The first approach for sharpening text is to apply a linear sharpening
-filter in image space through performing multiple texture accesses.
-Unfortunately, the sharpening increases aliasing artifacts with motion,
-which needs to be dealt with. One approach is fading off the sharpening
-as movement starts, in a kind of a "motion blur" effect.  The sharpening
-can be implemented optimally with a fragment program, and, with less
-quality, with a combination of register combiners and LOD-biasing.
-
-The second approach is to change the filtering paradigm entirely.
-This is possible because of the flexibility of e.g. the NV30.  We have
-had some encouraging results from using NEAREST-filtering in OpenGL,
-but where at each texel, the *texel distance* between the texel and the
-font outline is stored. This allows the filtering to be based more on
-the font outline and less the pixellated representation, approximating
-a real font rasterer on the GPU. 
-
-2. Subpixel rendering
----------------------
+Subpixel-rendered text modern GPUs
+==================================
 
 One approach to enhancing text legibility on LCD displays that
 has been gaining popularity in the recent years is subpixel rendering.
@@ -61,10 +25,7 @@
 
 Fig.1. Trilinearly filtered text.
 
-Fig.2. Text sharpened by a fragment program which uses the pre-calculated
-distance to the font shape from a texture.
-
-Fig.3. Subpixel-rendered (trilinearly filtered) text. On a CRT,
+Fig.2. Subpixel-rendered (trilinearly filtered) text. On a CRT,
 this looks more blurred than Fig.1; on a laptop with the right
 pixel ordering (RGB), it looks much better due to the subpixel
 resolution.