[Aqsis-commits] SF.net SVN: aqsis: [1942] trunk/aqsis/renderer/render

[<c4...@us...>]

Revision: 1942
          http://aqsis.svn.sourceforge.net/aqsis/?rev=1942&view=rev
Author:   c42f
Date:     2008-02-23 17:55:19 -0800 (Sat, 23 Feb 2008)

Log Message:
-----------
* Really (fingers crossed) fix the bug referred to in svn revision 1934.  The
  previous "fix" resulted in a crash according to a comment on IRC by Michel
  Joron.  Imager shaders should now run on all the vertices of a grid, rather
  than leaving the bottom right of the grid uninitialized.

Revision Links:
--------------
    http://aqsis.svn.sourceforge.net/aqsis/?rev=1934&view=rev

Modified Paths:
--------------
    trunk/aqsis/renderer/render/imagers.cpp
    trunk/aqsis/renderer/render/imagers.h

Modified: trunk/aqsis/renderer/render/imagers.cpp
===================================================================
--- trunk/aqsis/renderer/render/imagers.cpp	2008-02-24 00:56:25 UTC (rev 1941)
+++ trunk/aqsis/renderer/render/imagers.cpp	2008-02-24 01:55:19 UTC (rev 1942)
@@ -61,23 +61,17 @@
 }
 
 //---------------------------------------------------------------------
-/** Initialise the environment for the specified grid size
- *   and execute the shader on the complete grid.
- * \param uGridRes Integer grid resolution == 1.
- * \param vGridRes Integer grid resolution == 1.
- * \param x Integer Raster position.
- * \param y Integer Raster position.
- * \param color Initial value Ci.
- * \param opacity Initial value Oi.
- * \param depth Initial value depth (not required).
- * \param coverage Initial value "alpha"
- */
 void CqImagersource::Initialise( IqBucket* pBucket )
 {
 	TIME_SCOPE("Imager shading")
 
-	TqInt uGridRes = pBucket->Width();
-	TqInt vGridRes = pBucket->Height();
+	// We use one less than the bucket width and height here, since these
+	// resolutions really represent one less than the number of shaded points
+	// in each direction.  (Usually they describe the number of micropolygons
+	// on a grid which is one less than the number of shaded vertices.  This
+	// concept has no real analogue in context of an imager shader.)
+	TqInt uGridRes = pBucket->Width()-1;
+	TqInt vGridRes = pBucket->Height()-1;
 	TqInt x = pBucket->XOrigin();
 	TqInt y = pBucket->YOrigin();
 

Modified: trunk/aqsis/renderer/render/imagers.h
===================================================================
--- trunk/aqsis/renderer/render/imagers.h	2008-02-24 00:56:25 UTC (rev 1941)
+++ trunk/aqsis/renderer/render/imagers.h	2008-02-24 01:55:19 UTC (rev 1942)
@@ -70,7 +70,12 @@
 			return ( m_pShader );
 		}
 
-		void	Initialise( IqBucket* pBucket );
+		/** \brief Initialise and execute the imager shader over the provided bucket.
+		 *
+		 * \param pBucket - Bucket from which to take the source shader data for the
+		 *                  imager shader.
+		 */
+		void Initialise(IqBucket* pBucket);
 
 
 		// Forwarding functions for IqShaderExecEnv


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