From 11aed7474eba3aeca00cebf77ccece3c126cfa74 Mon Sep 17 00:00:00 2001
From: scrawl <scrawl@baseoftrash.de>
Date: Wed, 20 Mar 2013 18:34:54 +0100
Subject: [PATCH] Shadow cast on water

---
 files/materials/water.mat    | 19 +++++++++
 files/materials/water.shader | 76 +++++++++++++++++++++++++++++++++++-
 2 files changed, 93 insertions(+), 2 deletions(-)

diff --git a/files/materials/water.mat b/files/materials/water.mat
index 0ec71d2df..1e5f8c8e0 100644
--- a/files/materials/water.mat
+++ b/files/materials/water.mat
@@ -54,5 +54,24 @@ material Water
             scale 0.1 0.1
             alpha_op_ex source1 src_manual src_current 0.7
         }
+
+        texture_unit shadowMap0
+        {
+            content_type shadow
+            tex_address_mode clamp
+            filtering none
+        }
+        texture_unit shadowMap1
+        {
+            content_type shadow
+            tex_address_mode clamp
+            filtering none
+        }
+        texture_unit shadowMap2
+        {
+            content_type shadow
+            tex_address_mode clamp
+            filtering none
+        }
     }
 }
diff --git a/files/materials/water.shader b/files/materials/water.shader
index 793cdc95e..a6d0a47e6 100644
--- a/files/materials/water.shader
+++ b/files/materials/water.shader
@@ -50,6 +50,13 @@
 
 // Inspired by Blender GLSL Water by martinsh ( http://devlog-martinsh.blogspot.de/2012/07/waterundewater-shader-wip.html )
 
+#define SHADOWS_PSSM @shGlobalSettingBool(shadows_pssm)
+#define SHADOWS @shGlobalSettingBool(shadows)
+
+#if SHADOWS || SHADOWS_PSSM
+    #include "shadows.h"
+#endif
+
 #define RIPPLES 1
 #define REFRACTION @shGlobalSettingBool(refraction)
 
@@ -64,6 +71,23 @@
         shOutput(float4, position)
         shOutput(float, depthPassthrough)
 
+
+#if SHADOWS
+        shOutput(float4, lightSpacePos0)
+        shUniform(float4x4, texViewProjMatrix0) @shAutoConstant(texViewProjMatrix0, texture_viewproj_matrix)
+#endif
+
+#if SHADOWS_PSSM
+    @shForeach(3)
+        shOutput(float4, lightSpacePos@shIterator)
+        shUniform(float4x4, texViewProjMatrix@shIterator) @shAutoConstant(texViewProjMatrix@shIterator, texture_viewproj_matrix, @shIterator)
+    @shEndForeach
+#endif
+
+#if SHADOWS || SHADOWS_PSSM
+    shUniform(float4x4, worldMatrix) @shAutoConstant(worldMatrix, world_matrix)
+#endif
+
     SH_START_PROGRAM
     {
 	    shOutputPosition = shMatrixMult(wvp, shInputPosition);
@@ -88,6 +112,17 @@
         position = shInputPosition;
         
         depthPassthrough = shOutputPosition.z;
+
+
+#if SHADOWS
+        lightSpacePos0 = shMatrixMult(texViewProjMatrix0, shMatrixMult(worldMatrix, shInputPosition));
+#endif
+#if SHADOWS_PSSM
+        float4 wPos = shMatrixMult(worldMatrix, shInputPosition);
+    @shForeach(3)
+        lightSpacePos@shIterator = shMatrixMult(texViewProjMatrix@shIterator, wPos);
+    @shEndForeach
+#endif
     }
 
 #else
@@ -186,10 +221,47 @@
         shUniform(float4, fogParams) @shAutoConstant(fogParams, fog_params)
         
         shUniform(float4, cameraPos) @shAutoConstant(cameraPos, camera_position_object_space)
+
+
+#if SHADOWS
+        shInput(float4, lightSpacePos0)
+        shSampler2D(shadowMap0)
+        shUniform(float2, invShadowmapSize0)   @shAutoConstant(invShadowmapSize0, inverse_texture_size, 1)
+#endif
+#if SHADOWS_PSSM
+    @shForeach(3)
+        shInput(float4, lightSpacePos@shIterator)
+        shSampler2D(shadowMap@shIterator)
+        shUniform(float2, invShadowmapSize@shIterator)  @shAutoConstant(invShadowmapSize@shIterator, inverse_texture_size, @shIterator(1))
+    @shEndForeach
+    shUniform(float3, pssmSplitPoints)  @shSharedParameter(pssmSplitPoints)
+#endif
+
+#if SHADOWS || SHADOWS_PSSM
+        shUniform(float4, shadowFar_fadeStart) @shSharedParameter(shadowFar_fadeStart)
+#endif
 		
 
     SH_START_PROGRAM
     {
+#if SHADOWS
+            float shadow = depthShadowPCF (shadowMap0, lightSpacePos0, invShadowmapSize0);
+#endif
+#if SHADOWS_PSSM
+            float shadow = pssmDepthShadow (lightSpacePos0, invShadowmapSize0, shadowMap0, lightSpacePos1, invShadowmapSize1, shadowMap1, lightSpacePos2, invShadowmapSize2, shadowMap2, depthPassthrough, pssmSplitPoints);
+#endif
+
+#if SHADOWS || SHADOWS_PSSM
+            float fadeRange = shadowFar_fadeStart.x - shadowFar_fadeStart.y;
+            float fade = 1-((depthPassthrough - shadowFar_fadeStart.y) / fadeRange);
+            shadow = (depthPassthrough > shadowFar_fadeStart.x) ? 1.0 : ((depthPassthrough > shadowFar_fadeStart.y) ? 1.0-((1.0-shadow)*fade) : shadow);
+#endif
+
+#if !SHADOWS && !SHADOWS_PSSM
+            float shadow = 1.0;
+#endif
+
+
         float2 screenCoords = screenCoordsPassthrough.xy / screenCoordsPassthrough.z;
         screenCoords.y = (1-shSaturate(renderTargetFlipping))+renderTargetFlipping*screenCoords.y;
 
@@ -244,7 +316,7 @@
         float3 llR = reflect(lVec, pNormal);
         
         float s = shSaturate(dot(lR, vVec)*2.0-1.2);
-        float lightScatter = shSaturate(dot(-lVec,lNormal)*0.7+0.3) * s * SCATTER_AMOUNT * waterSunFade_sunHeight.x * shSaturate(1.0-exp(-waterSunFade_sunHeight.y));
+        float lightScatter = shadow * shSaturate(dot(-lVec,lNormal)*0.7+0.3) * s * SCATTER_AMOUNT * waterSunFade_sunHeight.x * shSaturate(1.0-exp(-waterSunFade_sunHeight.y));
         float3 scatterColour = shLerp(float3(SCATTER_COLOUR)*float3(1.0,0.4,0.0), SCATTER_COLOUR, shSaturate(1.0-exp(-waterSunFade_sunHeight.y*SUN_EXT)));
 
         // fresnel
@@ -267,7 +339,7 @@
 #endif
 
 		// specular
-        float specular = pow(max(dot(R, lVec), 0.0),SPEC_HARDNESS);
+        float specular = pow(max(dot(R, lVec), 0.0),SPEC_HARDNESS) * shadow;
 
 #if REFRACTION
         shOutputColour(0).xyz = shLerp(  shLerp(refraction, scatterColour, lightScatter), reflection, fresnel) + specular * sunSpecular.xyz;