Render ChangeLog, 1.5, 1.6 configure.ac, 1.3, 1.4 protocol, 1.8, 1.9 render.h, 1.13, 1.14 renderproto.h, 1.14, 1.15

Thu Jul 29 00:58:05 PDT 2004

Committed by: keithp

Update of /cvs/xlibs/Render
In directory pdx:/tmp/cvs-serv8477

Modified Files:
	ChangeLog configure.ac protocol render.h renderproto.h 
Log Message:
2004-07-29  Keith Packard  <keithp at keithp.com>

	* configure.ac:
	* protocol:
	* render.h:
	* renderproto.h:
	Specify new AddTraps request.
	Change pixelization specification.


Index: ChangeLog
===================================================================
RCS file: /cvs/xlibs/Render/ChangeLog,v
retrieving revision 1.5
retrieving revision 1.6
diff -u -d -r1.5 -r1.6

--- ChangeLog	4 Jul 2004 20:25:48 -0000	1.5
+++ ChangeLog	29 Jul 2004 07:58:03 -0000	1.6
@@ -1,3 +1,12 @@
+2004-07-29  Keith Packard  <keithp at keithp.com>
+
+	* configure.ac:
+	* protocol:
+	* render.h:
+	* renderproto.h:
+	Specify new AddTraps request.
+	Change pixelization specification.
+
 2004-07-03  Eric Anholt  <anholt at FreeBSD.org>
 
 	* render.h:

Index: configure.ac
===================================================================
RCS file: /cvs/xlibs/Render/configure.ac,v
retrieving revision 1.3
retrieving revision 1.4
diff -u -d -r1.3 -r1.4
--- configure.ac	10 Nov 2003 04:46:53 -0000	1.3
+++ configure.ac	29 Jul 2004 07:58:03 -0000	1.4
@@ -24,7 +24,7 @@
 dnl Process this file with autoconf to create configure.
 
 AC_PREREQ([2.57])
-AC_INIT([renderext], [0.8], [keithp at keithp.com], [renderext])
+AC_INIT([renderext], [0.9], [keithp at keithp.com], [renderext])
 AM_INIT_AUTOMAKE([dist-bzip2])
 AM_MAINTAINER_MODE
 

Index: protocol
===================================================================
RCS file: /cvs/xlibs/Render/protocol,v
retrieving revision 1.8
retrieving revision 1.9
diff -u -d -r1.8 -r1.9
--- protocol	3 May 2003 19:20:00 -0000	1.8
+++ protocol	29 Jul 2004 07:58:03 -0000	1.9
@@ -1,6 +1,6 @@
 			The X Rendering Extension
-			      Version 0.8
-			        2003-5-3
+			      Version 0.9
+			        2004-7-23
 			      Keith Packard
 			    keithp at keithp.com
 
@@ -29,7 +29,7 @@
 	how OpenGL works.
 
  +	Carl Worth for providing the sample implementation of
- 	trapezoid rendering
+ 	trapezoid rendering and showing how broken the spec was
 
  +	Sam Pottle and Jamey Sharp for helping demonstrate the correctness
  	of the trapezoid specification.
@@ -208,9 +208,13 @@
 			p1, p2:		POINTFIX
 		]
 TRAP		[
+			top, bottom:	SPANFIX
+		]
+TRAPEZOID	[
 			top, bottom:	FIXED
 			left, right:	LINEFIX
 		]
+(TRAPEZOID is deprecated)
 COLORTRIANGLE	[
 			p1, p2, p3:	COLORPOINT
 		]
@@ -372,22 +376,13 @@
 
 10. Polygon Rasterization
 
-All polygons must be convex.  Rendering of concave polygons is unspecified
-except that the result must obey the clipping rules.
-
-Each polygon request fills the region closed by the specified path.  The
-path is automatically closed if the last point does not coincide with the
-first point.
+Render provides only two kinds of polygons, trapezoids and triangles.  To
+improve efficiency, several different wire encodings exist for each. 
 
-A point is infinitely small and the path is an infinitely thin line.  A
-pixel is inside if the center point of the pixel is inside and the center
-point is not on the boundary.  If the center point is on the boundary, the
-pixel is inside if and only if the polygon interior is immediately to its
-right (x increasing direction).  Pixels with centers along a horizontal edge
-are a special case and are inside if and only if the polygon interior is
-immediately below (y increasing direction).  A polygon contains a pixel if
-the pixel is inside the polygon.
+All trapezoids must be convex.  Rendering of concave trapezoids is unspecified
+except that the result must obey the clipping rules.
 
+Composite
 Polygons are rasterized by implicit generating an alpha mask and using that
 in the general compositing operator along with a supplied source image:
 
@@ -404,21 +399,20 @@
 the alpha width in the fallback format before application of the compositing
 operator.
 
----
-
-This needs rewriting to match current trapezoid specification and
-base other polygons on that.  I suspect imprecise polygons will need
-to have a relaxed specification as well; hardware is unlikely to
-meet the "sum to one" constraint.
-
----
+Rasterization
+Alpha values are generated by point sampling the coverage of a square
+surrounding the center of each pixel by the polygon. 
 
-When rasterized in Precise mode, the pixelization will match this
-specification exactly.
+In Precise poly mode, the sample points are located in a regular grid.  When
+alpha depth 'e' is even, the regular grid is 2**(e/2) + 1 samples wide and
+2**(e/2) -1 samples high.  For odd alpha depth 'o', the sample grid is 2**o
+- 1 samples wide and 1 sample high.  Note that odd alpha depth usually
+occurs only at depth 1, so this misshapen sample grid has no ill effects.
+The sample grid is centered within the pixel and then each sample point is
+rounded down to a point on the sub-pixel coordinate grid.
 
-When rasterized in Imprecise mode, the pixelization may deviate from this
-specification by up to 1/2 pixel along any edge subject to the following
-constraints:
+In Imprecise mode, the location of the sample points is not specified, but
+the implementation must conform to the following constraints:
 
  +	Abutting edges must match precisely.  When specifying two polygons
 	abutting along a common edge, if that edge is specified with the
@@ -436,16 +430,6 @@
  +	Order independent. Two identical polygons specified with vertices
 	in different orders must generate identical results.
 
-Polygons can also be specified with colors for each vertex.  These color
-values are interpolated along the edges and across each scanline.
-
-When rasterized in Precise mode, the interpolated colors are exact.
-
-When rasterized in Imprecise mode, the color of each pixel may optionally be
-interpolated from a triangle containing the pixel which is formed from any
-three polygon vertices.  Any interpolated color value can err up to 1 lsb in
-each channel.
-
 11. Image Filtering
 
 When computing pixels from source and mask images, a filter may be applied
@@ -460,8 +444,8 @@
 
 	Filter Name	Description
 
-	Nearest		Nearest neighbor filtering
-	Bilinear	Linear interpolation in two dimensions
+	nearest		Nearest neighbor filtering
+	bilinear	Linear interpolation in two dimensions
 
 Additional names may be provided for any filter as aliases.  A set of
 standard alias names are required to be mapped to a provided filter so that
@@ -469,13 +453,29 @@
 
 	Alias name	Intended interpretation
 	
-	Fast		High performance, quality similar to Nearest
-	Good		Reasonable performance, quality similar to Bilinear
-	Best		Highest quality available, performance may not
+	fast		High performance, quality similar to Nearest
+	good		Reasonable performance, quality similar to Bilinear
+	best		Highest quality available, performance may not
 			be suitable for interactive use
 
 Aliases must map directly to a non-aliased filter name.
 
+There is also a set of standard filters which are not required but may be
+provided.  If they are provided, using the standard name, they must match
+the definition specified here.
+
+	Filter Name	Description
+	
+	convolution	MxN convolution filter.  The values specified
+			in SetPictureFilter are M, N and then M * N
+			filter parameters.  M and N must be integers
+			represented as fixed point numbers.
+	gaussian	Gaussian blur.  The value specified is a radius
+			in pixels (which can be fractional).  A standard
+			Gaussian 2D convolution filter will be applied.
+	binomial	Binomial blur. An approximation of a Gaussian
+			blur using binomial coefficients
+
 12. Glyph Rendering
 
 Glyphs are small alpha masks which can be stored in the X server and
@@ -816,14 +816,15 @@
 	src-x, src-y:   INT16
 	dst:		PICTURE
 	mask-format:	PICTFORMAT or None
-	traps:		LISTofTRAP
+	traps:		LISTofTRAPEZOID
 
-	This request rasterizes the list of trapezoids.  For each trap, the
-	area between the left and right edges is filled from the top to the
-	bottom.  src-x and src-y register the pattern to the floor of the
-	top x and y coordinate of the left edge of the first trapezoid, they
-	are adjusted for subsequent trapezoids so that the pattern remains
-	globally aligned within the destination.
+	This request rasterizes the list of trapezoids.
+	
+	For each trap, the area between the left and right edges is filled
+	from the top to the bottom.  src-x and src-y register the pattern to
+	the floor of the top x and y coordinate of the left edge of the
+	first trapezoid, they are adjusted for subsequent trapezoids so that
+	the pattern remains globally aligned within the destination.
 
 	When mask-format is not None, trapezoids are rendered in the
 	following way with the effective mask computed in mask-format:
@@ -1110,6 +1111,19 @@
 	'cursors', showing each cursor in the element for the number of
 	milliseconds indicated by the 'delay' member of that element.
 
+AddTraps
+	picture:	PICTURE
+	off-x, off-y:	INT16
+	trapezoids:	LISTofTRAP
+
+	Errors:		Match
+
+	Each trap is PictOpAdd'ed to 'picture'.  'off-x', 'off-y'
+	are added to each coordinate.
+
+	'picture' must be an alpha-only picture else a 'Match' error is
+	returned.
+	
 15. Extension Versioning
 
 The Render extension was developed in parallel with the implementation to
@@ -1158,3 +1172,5 @@
 		QueryPictIndexValues
 	0.8:
 		CreateAnimCursor
+	0.9:
+		AddTrapezoids

Index: render.h
===================================================================
RCS file: /cvs/xlibs/Render/render.h,v
retrieving revision 1.13
retrieving revision 1.14
diff -u -d -r1.13 -r1.14
--- render.h	4 Jul 2004 20:25:48 -0000	1.13
+++ render.h	29 Jul 2004 07:58:03 -0000	1.14
@@ -33,7 +33,7 @@
 
 #define RENDER_NAME	"RENDER"
 #define RENDER_MAJOR	0
-#define RENDER_MINOR	8
+#define RENDER_MINOR	9
 
 #define X_RenderQueryVersion		    0
 #define X_RenderQueryPictFormats	    1
@@ -68,8 +68,11 @@
 #define X_RenderSetPictureTransform	    28
 #define X_RenderQueryFilters		    29
 #define X_RenderSetPictureFilter	    30
+/* 0.8 */
 #define X_RenderCreateAnimCursor	    31
-#define RenderNumberRequests		    (X_RenderCreateAnimCursor+1)
+/* 0.9 */
+#define X_RenderAddTraps		    32
+#define RenderNumberRequests		    (X_RenderAddTraps+1)
 
 #define BadPictFormat			    0
 #define BadPicture			    1
@@ -155,6 +158,10 @@
 /* Filters included in 0.6 */
 #define FilterNearest			    "nearest"
 #define FilterBilinear			    "bilinear"
+/* Other standard, but not required filters */
+#define FilterConvolution		    "convolution"
+#define FilterGaussian			    "gaussian"
+#define FilterBinomial			    "binomial"
 
 #define FilterFast			    "fast"
 #define FilterGood			    "good"

Index: renderproto.h
===================================================================
RCS file: /cvs/xlibs/Render/renderproto.h,v
retrieving revision 1.14
retrieving revision 1.15
diff -u -d -r1.14 -r1.15
--- renderproto.h	21 Apr 2003 17:19:22 -0000	1.14
+++ renderproto.h	29 Jul 2004 07:58:03 -0000	1.15
@@ -168,6 +168,18 @@
 
 #define sz_xGlyphElt	8
 
+typedef struct {
+    Fixed   l, r, y;
+} xSpanFix;
+
+#define sz_xSpanFix	12
+
+typedef struct {
+    xSpanFix	top, bot;
+} xTrap;
+
+#define sz_xTrap	24
+
 /* 
  * requests and replies
  */
@@ -568,6 +580,19 @@
 
 #define sz_xRenderCreateAnimCursorReq		    8
 
+/* 0.9 and higher */
+
+typedef struct {
+    CARD8		reqType;
+    CARD8		renderReqType;
+    CARD16		length B16;
+    Picture		picture;
+    INT16		xOff B16;
+    INT16		yOff B16;
+} xRenderAddTrapsReq;
+
+#define sz_xRenderAddTrapsReq			    12
+    
 #undef Window
 #undef Drawable
 #undef Font

