Fix 3DGS holes

Author: MrNeRF

src/rendering/rasterizer/vulkan/shader/src/slang/config.slang

@@ -65,13 +65,8 @@
 #define MAX_RAW_SCALE 20.0f
 
 // subtile culling in rasterization
-#if TILE_HEIGHT >= 16 && TILE_WIDTH >= 16
-    #define SUBTILE_HEIGHT 4
-    #define SUBTILE_WIDTH 8
-#else
-    #define SUBTILE_HEIGHT 0
-    #define SUBTILE_WIDTH 0
-#endif
+#define SUBTILE_HEIGHT 0
+#define SUBTILE_WIDTH 0
 #define SUBTILE_SIZE (SUBTILE_HEIGHT*SUBTILE_WIDTH)
 
 

src/rendering/rasterizer/vulkan/shader/src/slang/utils.slang

@@ -983,8 +983,8 @@ float2 ellipse_range_bound(
     float bv0 = -b*v0, bv1 = -b*v1;
 
     float inv_a = 1.0f / a;
-    float x0 = inv_a * (bv0 - sqrt(bv0*bv0 - a*(c*v0*v0-1.f)));
-    float x1 = inv_a * (bv1 + sqrt(bv1*bv1 - a*(c*v1*v1-1.f)));
+    float x0 = inv_a * (bv0 - sqrt(max(bv0*bv0 - a*(c*v0*v0-1.f), 0.0f)));
+    float x1 = inv_a * (bv1 + sqrt(max(bv1*bv1 - a*(c*v1*v1-1.f), 0.0f)));
 
     return float2(x0, x1);