add fog

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

@@ -29,6 +29,7 @@ import com.seibel.distanthorizons.core.logging.DhLoggerBuilder;
 import com.seibel.distanthorizons.core.render.DhApiRenderProxy;
 import com.seibel.distanthorizons.core.render.RenderBufferHandler;
 import com.seibel.distanthorizons.core.render.renderer.generic.GenericObjectRenderer;
+import com.seibel.distanthorizons.core.util.math.Mat4f;
 import com.seibel.distanthorizons.core.util.math.Vec3d;
 import com.seibel.distanthorizons.core.util.objects.SortedArraySet;
 import com.seibel.distanthorizons.core.wrapperInterfaces.minecraft.IMinecraftClientWrapper;
@@ -148,6 +149,7 @@ public class McLodRenderer
 		
 		IMcLodRenderer lodRenderer = SingletonInjector.INSTANCE.get(IMcLodRenderer.class);
 		IMcSsaoRenderer ssaoRenderer = SingletonInjector.INSTANCE.get(IMcSsaoRenderer.class);
+		IMcFogRenderer fogRenderer = SingletonInjector.INSTANCE.get(IMcFogRenderer.class);
 		
 		
 		
@@ -214,12 +216,12 @@ public class McLodRenderer
 				// this is done to fix issues with: underwater fog, blindness effect, etc.
 				|| renderParams.vanillaFogEnabled)
 			{
-				//profiler.popPush("LOD Fog");
-				//
-				//Mat4f combinedMatrix = new Mat4f(renderParams.dhProjectionMatrix);
-				//combinedMatrix.multiply(renderParams.dhModelViewMatrix);
-				//
-				//FogRenderer.INSTANCE.render(combinedMatrix, renderParams.partialTicks);
+				profiler.popPush("LOD Fog");
+
+				Mat4f combinedMatrix = new Mat4f(renderParams.dhProjectionMatrix);
+				combinedMatrix.multiply(renderParams.dhModelViewMatrix);
+				
+				fogRenderer.render(combinedMatrix, renderParams.partialTicks);
 			}
 			
 			

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

@@ -243,9 +243,9 @@ public class FogShader extends AbstractShaderRenderer
 		return fogColor;
 	}
 	
-	public void setProjectionMatrix(Mat4f projectionMatrix)
+	public void setProjectionMatrix(Mat4f modelViewProjectionMatrix)
 	{
-		this.inverseMvmProjMatrix = new Mat4f(projectionMatrix);
+		this.inverseMvmProjMatrix = new Mat4f(modelViewProjectionMatrix);
 		this.inverseMvmProjMatrix.invert();
 	}
 	

core/src/main/java/com/seibel/distanthorizons/core/wrapperInterfaces/render/IMcFogRenderer.java

@@ -0,0 +1,30 @@
+/*
+ *    This file is part of the Distant Horizons mod
+ *    licensed under the GNU LGPL v3 License.
+ *
+ *    Copyright (C) 2020 James Seibel
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU Lesser General Public License as published by
+ *    the Free Software Foundation, version 3.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Lesser General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Lesser General Public License
+ *    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.seibel.distanthorizons.core.wrapperInterfaces.render;
+
+import com.seibel.distanthorizons.api.objects.math.DhApiMat4f;
+import com.seibel.distanthorizons.coreapi.interfaces.dependencyInjection.IBindable;
+
+public interface IMcFogRenderer extends IBindable
+{
+	
+	void render(DhApiMat4f modelViewProjectionMatrix, float partialTicks);
+	
+}

core/src/main/resources/assets/distanthorizons/shaders/fog/apply.fsh

@@ -0,0 +1,27 @@
+#version 150 core
+
+in vec2 TexCoord;
+
+out vec4 fragColor;
+
+uniform sampler2D uColorTexture;
+uniform sampler2D uDhDepthTexture;
+
+
+/** 
+ * Fog application shader
+ *
+ * This merges the rendered fog onto DH's rendered LODs
+ */
+void main()
+{
+    fragColor = vec4(0.0);
+
+    // a fragment depth of "1" means the fragment wasn't drawn to,
+    // only update fragments that were drawn to
+    float fragmentDepth = textureLod(uDhDepthTexture, TexCoord, 0).r;
+    if (fragmentDepth != 1)
+    {
+        fragColor = texture(uColorTexture, TexCoord);
+    }
+}

core/src/main/resources/assets/distanthorizons/shaders/fog/fog.fsh

@@ -0,0 +1,299 @@
+#version 150 core
+
+in vec2 TexCoord;
+
+out vec4 fragColor;
+
+layout (std140) uniform fragUniformBlock
+{
+    // fog uniforms
+    vec4 uFogColor;
+    float uFogScale;
+    float uFogVerticalScale;
+    int uFogDebugMode;
+    int uFogFalloffType;
+    
+    // fog config
+    float uFarFogStart;
+    float uFarFogLength;
+    float uFarFogMin;
+    float uFarFogRange;
+    float uFarFogDensity;
+    
+    // height fog config
+    float uHeightFogStart;
+    float uHeightFogLength;
+    float uHeightFogMin;
+    float uHeightFogRange;
+    float uHeightFogDensity;
+    
+    // ???
+    bool uHeightFogEnabled;
+    int uHeightFogFalloffType;
+    bool uHeightBasedOnCamera;
+    float uHeightFogBaseHeight;
+    bool uHeightFogAppliesUp;
+    bool uHeightFogAppliesDown;
+    bool uUseSphericalFog;
+    int uHeightFogMixingMode;
+    float uCameraBlockYPos;
+    
+    // inverted model view matrix and projection matrix
+    mat4 uInvMvmProj;
+};
+
+uniform sampler2D uDhDepthTexture;
+
+
+
+//====================//
+// method definitions //
+//====================//
+
+vec3 calcViewPosition(float fragmentDepth);
+
+float getFarFogThickness(float dist);
+float getHeightFogThickness(float dist);
+float calculateHeightFogDepth(float worldYPos);
+float mixFogThickness(float far, float height);
+
+float linearFog(float worldDist, float fogStart, float fogLength, float fogMin, float fogRange);
+float exponentialFog(float x, float fogStart, float fogLength, float fogMin, float fogRange, float fogDensity);
+float exponentialSquaredFog(float x, float fogStart, float fogLength, float fogMin, float fogRange, float fogDensity);
+
+
+
+//======//
+// main //
+//======//
+
+/**
+ * Fragment shader for fog.
+ * This should be run last so it applies above other affects like Ambient Occlusioning
+ */
+void main()
+{
+    float fragmentDepth = texture(uDhDepthTexture, TexCoord).r;
+    fragColor = vec4(uFogColor.rgb, 0.0);
+
+    // a fragment depth of "1" means the fragment wasn't drawn to,
+    // we only want to apply Fog to LODs, not to the sky outside the LODs
+    if (fragmentDepth < 1.0)
+    {
+        int fogDebugMode = uFogDebugMode;
+        if (fogDebugMode == 0)
+        {
+            // render fog based on distance from the camera
+            vec3 vertexWorldPos = calcViewPosition(fragmentDepth);
+
+            float horizontalWorldDistance = length(vertexWorldPos.xz) * uFogScale;
+            float worldDistance = length(vertexWorldPos.xyz) * uFogScale;
+            float activeDistance = uUseSphericalFog ? worldDistance : horizontalWorldDistance;
+
+
+            // far fog
+            float farFogThickness = getFarFogThickness(activeDistance);
+
+            // height fog
+            float heightFogDepth = calculateHeightFogDepth(vertexWorldPos.y);
+            float heightFogThickness = getHeightFogThickness(heightFogDepth);
+
+            // combined fog
+            float mixedFogThickness = mixFogThickness(farFogThickness, heightFogThickness);
+            fragColor.a = clamp(mixedFogThickness, 0.0, 1.0);
+        }
+        else if (fogDebugMode == 1)
+        {
+            // test code
+            
+            // render everything with the fog color
+            fragColor.a = 1.0;
+        }
+        else
+        {
+            // test code.
+
+            // this can be fired by manually changing the fullFogMode to a (normally)
+            // invalid value (like 7). 
+            // By having a separate if statement defined by
+            // a uniform we don't have to worry about GLSL optimizing away different
+            // options when testing, causing a bunch of headaches if we just want to render the screen red.
+
+            float depthValue = textureLod(uDhDepthTexture, TexCoord, 0).r;
+            fragColor.rgb = vec3(depthValue); // Convert depth value to grayscale color
+            fragColor.a = 1.0;
+        }
+    }
+}
+
+
+
+//================//
+// helper methods //
+//================//
+
+vec3 calcViewPosition(float fragmentDepth)
+{
+    vec4 ndc = vec4(TexCoord.xy, fragmentDepth, 1.0);
+    ndc.xyz = ndc.xyz * 2.0 - 1.0;
+
+    vec4 eyeCoord = uInvMvmProj * ndc;
+    return eyeCoord.xyz / eyeCoord.w;
+}
+
+
+
+//=========//
+// far fog //
+//=========//
+
+float getFarFogThickness(float dist)
+{
+    if (uFogFalloffType == 0) // LINEAR
+    {
+        return linearFog(dist, uFarFogStart, uFarFogLength, uFarFogMin, uFarFogRange);
+    }
+    else if (uFogFalloffType == 1) // EXPONENTIAL
+    {
+        return exponentialFog(dist, uFarFogStart, uFarFogLength, uFarFogMin, uFarFogRange, uFarFogDensity);
+    }
+    else // EXPONENTIAL_SQUARED
+    {
+        return exponentialSquaredFog(dist, uFarFogStart, uFarFogLength, uFarFogMin, uFarFogRange, uFarFogDensity);
+    }
+}
+
+float getHeightFogThickness(float dist)
+{
+    if (!uHeightFogEnabled)
+    {
+        return 0.0;
+    }
+
+    if (uHeightFogFalloffType == 0) // LINEAR
+    {
+        return linearFog(dist, uHeightFogStart, uHeightFogLength, uHeightFogMin, uHeightFogRange);
+    }
+    else if (uHeightFogFalloffType == 1) // EXPONENTIAL
+    {
+        return exponentialFog(dist, uHeightFogStart, uHeightFogLength, uHeightFogMin, uHeightFogRange, uHeightFogDensity);
+    }
+    else // EXPONENTIAL_SQUARED
+    {
+        return exponentialSquaredFog(dist, uHeightFogStart, uHeightFogLength, uHeightFogMin, uHeightFogRange, uHeightFogDensity);
+    }
+}
+
+float linearFog(float worldDist, float fogStart, float fogLength, float fogMin, float fogRange)
+{
+    worldDist = (worldDist - fogStart) / fogLength;
+    worldDist = clamp(worldDist, 0.0, 1.0);
+    return fogMin + fogRange * worldDist;
+}
+
+float exponentialFog(
+    float x, float fogStart, float fogLength,
+    float fogMin, float fogRange, float fogDensity)
+{
+    x = max((x-fogStart)/fogLength, 0.0) * fogDensity;
+    return fogMin + fogRange - fogRange/exp(x);
+}
+
+float exponentialSquaredFog(
+    float x, float fogStart, float fogLength,
+    float fogMin, float fogRange, float fogDensity)
+{
+    x = max((x-fogStart)/fogLength, 0.0) * fogDensity;
+    return fogMin + fogRange - fogRange/exp(x*x);
+}
+
+
+
+//============//
+// height fog //
+//============//
+
+/** 1 = full fog, 0 = no fog */
+float calculateHeightFogDepth(float worldYPos)
+{
+    // worldYPos -65 - 384
+
+
+    //worldYPos = worldYPos * -1; // negative, fog below height; positive, fog above height
+    //return worldYPos * uFogVerticalScale; // "* uFogVerticalScale" is done to convert world position to a percent of the world height;
+
+    if (!uHeightFogEnabled)
+    {
+        // ignore the height
+        return 0.0;
+    }
+
+
+    if (!uHeightBasedOnCamera)
+    {
+        worldYPos -= (uHeightFogBaseHeight - uCameraBlockYPos);
+    }
+
+
+    if (uHeightFogAppliesDown && uHeightFogAppliesUp)
+    {
+        return abs(worldYPos) * uFogVerticalScale;
+    }
+    else if (uHeightFogAppliesDown)
+    {
+        // apploy fog below given height
+        return -worldYPos * uFogVerticalScale;
+    }
+    else if (uHeightFogAppliesUp)
+    {
+        // apply fog above given height
+        return worldYPos * uFogVerticalScale;
+    }
+    else
+    {
+        // shouldn't happen,
+        return 0.0;
+    }
+
+}
+
+float mixFogThickness(float far, float height)
+{
+    switch (uHeightFogMixingMode)
+    {
+        case 0: // BASIC
+        case 1: // IGNORE_HEIGHT 
+        return far;
+
+        case 2: // MAX
+        return max(far, height);
+
+        case 3: // ADDITION
+        return (far + height);
+
+        case 4: // MULTIPLY
+        return far * height;
+
+        case 5: // INVERSE_MULTIPLY
+        return (1.0 - (1.0-far)*(1.0-height));
+
+        case 6: // LIMITED_ADDITION
+        return (far + max(far, height));
+
+        case 7: // MULTIPLY_ADDITION
+        return (far + far*height);
+
+        case 8: // INVERSE_MULTIPLY_ADDITION
+        return (far + 1.0 - (1.0-far)*(1.0-height));
+
+        case 9: // AVERAGE
+        return (far*0.5 + height*0.5);
+    }
+
+    // shouldn't happen, but default to BASIC / IGNORE_HEIGHT
+    // if an invalid option is selected
+    return far;
+}
+
+
+

core/src/main/resources/assets/distanthorizons/shaders/fog/quad_apply.vsh

@@ -0,0 +1,15 @@
+#version 150 core
+
+in vec2 vPosition;
+
+out vec2 TexCoord;
+
+/** 
+ * This is specifically used by application shaders.
+ * IE post process or pixel transfer shaders, anything that is rendered using a single rectangle.
+ */
+void main()
+{
+    gl_Position = vec4(vPosition, 1.0, 1.0);
+    TexCoord = vPosition.xy * 0.5 + 0.5;
+}