From 712e58da831e1eb643b45d9750f5ae67dc621329 Mon Sep 17 00:00:00 2001
From: Christopher Tenter <christopher.tenter@rwth-aachen.de>
Date: Thu, 22 Jan 2015 19:47:02 +0000
Subject: [PATCH] fix artifacts at pixels where too many layers overlap
 (OITLinkedList)

git-svn-id: http://www.openflipper.org/svnrepo/OpenFlipper/branches/Free-Staging@20191 383ad7c9-94d9-4d36-a494-682f7c89f535
---
 .../Shaders/OITLinkedList/resolve.glsl        | 113 +++++++++---------
 1 file changed, 59 insertions(+), 54 deletions(-)

diff --git a/PluginCollection-Renderers/Plugin-Render-OITLinkedList/Shaders/OITLinkedList/resolve.glsl b/PluginCollection-Renderers/Plugin-Render-OITLinkedList/Shaders/OITLinkedList/resolve.glsl
index a1b20e8..313b00b 100644
--- a/PluginCollection-Renderers/Plugin-Render-OITLinkedList/Shaders/OITLinkedList/resolve.glsl
+++ b/PluginCollection-Renderers/Plugin-Render-OITLinkedList/Shaders/OITLinkedList/resolve.glsl
@@ -18,7 +18,7 @@ layout(binding = 1, rgba32ui)  uniform uimageBuffer g_ABuffer;
 uniform uvec2 g_ScreenSize;
 
 
-struct FragListEntry 
+struct FragListEntry
 {
   uint color;
   float depth;
@@ -29,75 +29,80 @@ void main()
 {
   uvec2 absFragCoord = uvec2(gl_FragCoord.xy); // * g_ScreenSize);
   uint uiPixelID = absFragCoord.x + g_ScreenSize.x * absFragCoord.y;
-  
+
   // sorted list of the current pixel list
   FragListEntry list[MAXLISTSIZE];
-  
+
   // get offset to head of the list
   uint uiOffset = imageLoad(g_StartOffsetBuffer, int(uiPixelID)).r;
   uint startOffset = uiOffset;
-  
+
   // keep track of list size
   int listSize = 0;
-  
-  vec4 dbgColor = vec4(1,1,1,1);
-  
+
+  vec4 dbgColor = vec4(1, 1, 1, 1);
+
   // read linked list from ABuffer, starting at offset of list head
-  while (uiOffset != 0xffffffff && listSize < MAXLISTSIZE)
+  while (uiOffset != 0xffffffff)
   {
-	uvec4 fragEntry = imageLoad(g_ABuffer, int(uiOffset));
-	// fragEntry :  (color, depth, next, coverage)
-	
+    uvec4 fragEntry = imageLoad(g_ABuffer, int(uiOffset));
+    // fragEntry :  (color, depth, next, coverage)
+
 #ifdef  OITLL_MSAA
-	// check if sample is covered by rasterized triangle
-	if ((fragEntry.w & (1 << gl_SampleID)) != 0)
+    // check if sample is covered by rasterized triangle
+    if ((fragEntry.w & (1 << gl_SampleID)) != 0)
 #endif
-	{
-	
-	list[listSize].color = fragEntry.x;
-	list[listSize].depth = uintBitsToFloat(fragEntry.y);
-	
-	
-	// insertion sort
-	int j = listSize;
-	int prev = max(j-1, 0);
-	
-	// insertion sort: front to back
-	while( (j > 0) && (list[prev].depth > list[j].depth) )
-	{
-	  // swap
-	  FragListEntry tmp = list[j];
-	  list[j] = list[prev];
-	  list[prev] = tmp;
-	  
-	  --j;
-	  prev = max(j-1, 0);
-	}
-	
-	listSize = min(listSize+1, MAXLISTSIZE);
-
-	}
-
-	// goto next entry
-	uiOffset = fragEntry.z;
+    {
+
+      float fragDepth = uintBitsToFloat(fragEntry.y);
+
+
+
+      if (listSize < MAXLISTSIZE || list[listSize - 1].depth > fragDepth)
+      {
+        int insertPos = min(listSize, MAXLISTSIZE - 1);
+
+        list[insertPos].color = fragEntry.x;
+        list[insertPos].depth = fragDepth;
+
+
+        // insertion sort
+        int j = insertPos;
+        int prev = max(j - 1, 0);
+
+        // insertion sort: front to back
+        while ((j > 0) && (list[prev].depth > list[j].depth))
+        {
+          // swap
+          FragListEntry tmp = list[j];
+          list[j] = list[prev];
+          list[prev] = tmp;
+
+          --j;
+          prev = max(j - 1, 0);
+        }
+
+        listSize = min(listSize + 1, MAXLISTSIZE);
+      }
+
+
+
+    }
+
+    // goto next entry
+    uiOffset = fragEntry.z;
   }
-  
-  vec4 color = vec4(0,0,0,1);
-  
+
+  vec4 color = vec4(0, 0, 0, 1);
+
   // blend back to front
-  
-  for (int i = listSize-1; i >= 0; --i)
+
+  for (int i = listSize - 1; i >= 0; --i)
   {
     vec4 fragColor = unpackUnorm4x8(list[i].color);
-	
-	color.xyz = mix(color.xyz, fragColor.xyz, fragColor.w);
+
+    color.xyz = mix(color.xyz, fragColor.xyz, fragColor.w);
   }
 
   outColor = color; // * gl_NumSamples;
- 
- 
-  // weird bug, for some reason color != (0,0,0,1) for unshaded pixels
-  if (startOffset == 0xffffffff)
-    outColor = vec4(0,0,0,1);
- 
 }
-- 
GitLab