[Gzz-commits] gzz/Documentation/Manuscripts/Irregu irregu.tex

[Janne V. Kujala]

CVSROOT:        /cvsroot/gzz
Module name:    gzz
Changes by:     Janne V. Kujala <address@hidden>        02/11/13 07:27:49

Modified files:
        Documentation/Manuscripts/Irregu: irregu.tex 

Log message:
        multi and offset texture

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/gzz/Documentation/Manuscripts/Irregu/irregu.tex.diff?tr1=1.35&tr2=1.36&r1=text&r2=text

Patches:
Index: gzz/Documentation/Manuscripts/Irregu/irregu.tex
diff -u gzz/Documentation/Manuscripts/Irregu/irregu.tex:1.35 
gzz/Documentation/Manuscripts/Irregu/irregu.tex:1.36
--- gzz/Documentation/Manuscripts/Irregu/irregu.tex:1.35        Wed Nov 13 
07:23:44 2002
+++ gzz/Documentation/Manuscripts/Irregu/irregu.tex     Wed Nov 13 07:27:49 2002
@@ -346,7 +346,7 @@
 
 [GL\_EXT\_texture\_env\_add or OpenGL 1.3 required]
 
-
+\if0
 \subsection{A shape with the correct type of motion}
 
 Drawing a shape with the correct properties is relatively
@@ -360,6 +360,7 @@
 paper coordinates as texture coordinates. For attached edges, 
 project the points to a line at $x=.5$ along the $x$-axis
 and use those texture coordinates.
+\fi
 
 IMAGE
 
@@ -397,6 +398,32 @@
 
 Image-space algorithm: ... slow on NV10
 
+\subsubsection{Mutltitexture/access}
+
+Similar to image-space algorithms: values of surrounding fragments
+computed in parallel for each fragment.
+
+Attached edges: texture coordinates do not change along a
+normal of the tearing line.
+Simply set up texture units so that each one has
+the same bound texture but texture coordinates a distance corresponding
+to one pixel apart along the tearing line. 
+The read texture values are displacements of the inner edge 
+from the tearing line.
+A fragment is inside the outer edge, if its distance from
+any of the adjacent inner edge points is less than the line width.
+This computation can be carried out using GL\_NV\_register\_combiners
+or with an NV30 fragment program.
+Also, with NV30, a single texture unit can be accessed multiple
+times with displaced texture coordinates computed in the program.
+
+For sprinkled edges, one-dimensional displacements of the
+texture coordinates are not enough, because the texture slice
+mapped on the edge is two-dimensional. 
+Most OpenGL hardware do not have enough texture units for this,
+but with NV30, one could compute 
+XXX pixel and four surrounding pixels.
+
 \subsubsection{Optimizations}
 
 Pre-computed edge width: interpolated between
@@ -461,6 +488,10 @@
 - complexity of vertex computations \\
 - repeated vertices (non-continuos per-vertex data) \\
 - antialias \\
+
+\subsubsection{Offset texture}
+
+For attached edges
 
 \subsection{Tearout shapes}