Improve dithering quality

core/src/main/java/com/seibel/distanthorizons/core/render/renderer/DhTerrainShaderProgram.java

@@ -196,10 +196,8 @@ public class DhTerrainShaderProgram extends ShaderProgram implements IDhApiShade
 		
 		// Clip Uniform
 		float dhNearClipDistance = RenderUtil.getNearClipPlaneDistanceInBlocks(renderParameters.partialTicks);
-		// TODO a different multiplier might be necessary
-		//  this is to try and allow the fragment culling to go farther than the near clip plane.
-		//  Currently this only works for certain FOV/screen ratio combos.
-		dhNearClipDistance *= 2.0f;
+		// this added value prevents the near clip plane and discard circle from touching, which looks bad
+		dhNearClipDistance += 16f;
 		// if the player is very high up and the near clip plane has been modified, disable the distance clipping
 		// we're high enough that nothing will render on top of the player and this can cause issues otherwise
 		if (RenderUtil.getHeightBasedNearClipOverride() != -1)

core/src/main/java/com/seibel/distanthorizons/core/render/renderer/shaders/FadeShader.java

@@ -110,10 +110,15 @@ public class FadeShader extends AbstractShaderRenderer
 		if (this.inverseDhMvmProjMatrix != null) this.shader.setUniform(this.uDhInvMvmProj, this.inverseDhMvmProjMatrix);
 		
 		
-		int vanillaBlockRenderDistance = MC_RENDER.getRenderDistance() * LodUtil.CHUNK_WIDTH;
+		float dhNearClipDistance = RenderUtil.getNearClipPlaneDistanceInBlocks(partialTicks);
+		// this added value prevents the near clip plane and discard circle from touching, which looks bad
+		dhNearClipDistance += 16f;
+		
 		// measured in blocks
-		float fadeStartDistance = vanillaBlockRenderDistance * 0.5f;
-		float fadeEndDistance = vanillaBlockRenderDistance * 0.8f;
+		// these multipliers in James' tests should provide a fairly smooth transition
+		// without having underdraw issues
+		float fadeStartDistance = dhNearClipDistance * 1.5f;
+		float fadeEndDistance = dhNearClipDistance * 1.9f;
 		
 		if (this.uStartFadeBlockDistance != -1) this.shader.setUniform(this.uStartFadeBlockDistance, fadeStartDistance);
 		if (this.uEndFadeBlockDistance != -1) this.shader.setUniform(this.uEndFadeBlockDistance, fadeEndDistance);

core/src/main/java/com/seibel/distanthorizons/core/util/RenderUtil.java

@@ -114,7 +114,7 @@ public class RenderUtil
 		
 		// modify based on the player's FOV
 		double fov = MC_RENDER.getFov(partialTicks);
-		double aspectRatio = (double) MC_RENDER.getScreenWidth() / MC_RENDER.getScreenHeight();
+		double aspectRatio = (double) MC_RENDER.getTargetFrameBufferViewportWidth() / MC_RENDER.getTargetFrameBufferViewportHeight();
 		
 		// source: https://stackoverflow.com/questions/8101119/how-do-i-methodically-choose-the-near-clip-plane-distance-for-a-perspective-proj/8101234#8101234
 		return (float) (nearClipPlane

core/src/main/resources/shaders/flat_shaded.frag

@@ -61,9 +61,8 @@ void applyNoise(inout vec4 fragColor, const in float viewDist)
     fragColor.rgb = newCol;
 }
 
-float random(vec2 st) {
-    return fract(sin(dot(st.xy, vec2(12.9898, 78.233))) * 43758.5453);
-}
+float worldPosToNoise(vec2 st) { return fract(sin(dot(st.xy, vec2(12.9898, 78.233))) * 43758.5453); }
+
 
 
 void main()
@@ -74,18 +73,20 @@ void main()
     
     if (uDitherDhRendering)
     {
-        // only for opaque pass //
-        
         // Dither out the fragment based on distance and noise.
-        float noiseValue = random(vertexWorldPos.xy);
+        // Dithering is used since it works for both opaque and transparent rendering
+        
+        // noise increases as the distance increases
+        float worldNoise = worldPosToNoise(vertexWorldPos.xy);
         float fadeStep = smoothstep(uClipDistance, uClipDistance * 1.5, viewDist);
-        if (fadeStep < noiseValue)
+        if (fadeStep < worldNoise)
         {
-            discard; // Discard if the fadeStep is less than the noise.
+            discard;
         }
         
         
-        // only for transparent pass //
+        // this logic could be used for transparent rendering,
+        // however we don't currently have the logic needed to differentiate opaque/transparenet rendering
         //float fadeStep = smoothstep(uClipDistance, uClipDistance * 2, viewDist);
         //fragColor.a = min(fadeStep, fragColor.a);
     }