From f50063402dea5ab8a2e1badd2e7566d1ca100cbf Mon Sep 17 00:00:00 2001
From: AnyOldName3 <krizdjali+github@gmail.com>
Date: Thu, 21 Sep 2017 00:25:48 +0100
Subject: [PATCH] Adjust shaders to support shadows

---
 CI/before_script.msvc.sh            |  2 +-
 files/shaders/lighting.glsl         | 28 +++++++++++++++++++++-------
 files/shaders/objects_fragment.glsl | 13 ++++++++++---
 files/shaders/objects_vertex.glsl   |  6 ++++++
 files/shaders/terrain_fragment.glsl | 13 ++++++++++---
 files/shaders/terrain_vertex.glsl   |  6 ++++++
 6 files changed, 54 insertions(+), 14 deletions(-)

diff --git a/CI/before_script.msvc.sh b/CI/before_script.msvc.sh
index 14998a3c6..11317a33f 100644
--- a/CI/before_script.msvc.sh
+++ b/CI/before_script.msvc.sh
@@ -761,7 +761,7 @@ if [ -z $CI ]; then
 	echo "    settings-default.cfg"
 	cp settings-default.cfg $BUILD_CONFIG/settings-default.cfg
 	echo "    resources/"
-	cp -r resources $BUILD_CONFIG/resources
+	cp -r resources $BUILD_CONFIG
 	echo
 fi
 
diff --git a/files/shaders/lighting.glsl b/files/shaders/lighting.glsl
index 7b8486fbe..892ae485a 100644
--- a/files/shaders/lighting.glsl
+++ b/files/shaders/lighting.glsl
@@ -1,10 +1,23 @@
 #define MAX_LIGHTS 8
 
-vec4 doLighting(vec3 viewPos, vec3 viewNormal, vec4 vertexColor)
+vec3 perLight(int lightIndex, vec3 viewPos, vec3 viewNormal, vec4 diffuse, vec3 ambient)
 {
     vec3 lightDir;
     float d;
 
+	lightDir = gl_LightSource[lightIndex].position.xyz - (viewPos.xyz * gl_LightSource[lightIndex].position.w);
+    d = length(lightDir);
+    lightDir = normalize(lightDir);
+
+    return (ambient * gl_LightSource[lightIndex].ambient.xyz + diffuse.xyz * gl_LightSource[lightIndex].diffuse.xyz * max(dot(viewNormal.xyz, lightDir), 0.0)) * clamp(1.0 / (gl_LightSource[lightIndex].constantAttenuation + gl_LightSource[lightIndex].linearAttenuation * d + gl_LightSource[lightIndex].quadraticAttenuation * d * d), 0.0, 1.0);
+}
+
+#ifdef FRAGMENT
+vec4 doLighting(vec3 viewPos, vec3 viewNormal, vec4 vertexColor, float shadowing)
+#else
+vec4 doLighting(vec3 viewPos, vec3 viewNormal, vec4 vertexColor)
+#endif
+{
 #if @colorMode == 3
     vec4 diffuse = gl_FrontMaterial.diffuse;
     vec3 ambient = vertexColor.xyz;
@@ -17,13 +30,14 @@ vec4 doLighting(vec3 viewPos, vec3 viewNormal, vec4 vertexColor)
 #endif
     vec4 lightResult = vec4(0.0, 0.0, 0.0, diffuse.a);
 
-    for (int i=0; i<MAX_LIGHTS; ++i)
+#ifdef FRAGMENT
+	lightResult.xyz += perLight(0, viewPos, viewNormal, diffuse, ambient) * shadowing;
+#else
+	lightResult.xyz += perLight(0, viewPos, viewNormal, diffuse, ambient);
+#endif
+    for (int i=1; i<MAX_LIGHTS; ++i)
     {
-        lightDir = gl_LightSource[i].position.xyz - (viewPos.xyz * gl_LightSource[i].position.w);
-        d = length(lightDir);
-        lightDir = normalize(lightDir);
-
-        lightResult.xyz += (ambient * gl_LightSource[i].ambient.xyz + diffuse.xyz * gl_LightSource[i].diffuse.xyz * max(dot(viewNormal.xyz, lightDir), 0.0)) * clamp(1.0 / (gl_LightSource[i].constantAttenuation + gl_LightSource[i].linearAttenuation * d + gl_LightSource[i].quadraticAttenuation * d * d), 0.0, 1.0);
+        lightResult.xyz += perLight(i, viewPos, viewNormal, diffuse, ambient);
     }
 
     lightResult.xyz += gl_LightModel.ambient.xyz * ambient;
diff --git a/files/shaders/objects_fragment.glsl b/files/shaders/objects_fragment.glsl
index 5a72b44b3..d4823e9c1 100644
--- a/files/shaders/objects_fragment.glsl
+++ b/files/shaders/objects_fragment.glsl
@@ -1,5 +1,7 @@
 #version 120
 
+#define FRAGMENT
+
 #if @diffuseMap
 uniform sampler2D diffuseMap;
 varying vec2 diffuseMapUV;
@@ -54,6 +56,9 @@ varying vec4 passColor;
 varying vec3 passViewPos;
 varying vec3 passNormal;
 
+uniform sampler2DShadow shadowTexture;
+varying vec4 shadowSpaceCoords;
+
 #include "lighting.glsl"
 #include "parallax.glsl"
 
@@ -112,10 +117,12 @@ void main()
     gl_FragData[0].xyz = mix(gl_FragData[0].xyz, decalTex.xyz, decalTex.a);
 #endif
 
+	float shadowing = shadow2DProj(shadowTexture, shadowSpaceCoords).r;
+
 #if !PER_PIXEL_LIGHTING
-    gl_FragData[0] *= lighting;
+    gl_FragData[0] *= lighting * shadowing;
 #else
-    gl_FragData[0] *= doLighting(passViewPos, normalize(viewNormal), passColor);
+    gl_FragData[0] *= doLighting(passViewPos, normalize(viewNormal), passColor, shadowing);
 #endif
 
 #if @emissiveMap
@@ -147,7 +154,7 @@ void main()
     vec3 matSpec = gl_FrontMaterial.specular.xyz;
 #endif
 
-    gl_FragData[0].xyz += getSpecular(normalize(viewNormal), normalize(passViewPos.xyz), shininess, matSpec);
+    gl_FragData[0].xyz += getSpecular(normalize(viewNormal), normalize(passViewPos.xyz), shininess, matSpec) * shadowing;
 
     float fogValue = clamp((depth - gl_Fog.start) * gl_Fog.scale, 0.0, 1.0);
     gl_FragData[0].xyz = mix(gl_FragData[0].xyz, gl_Fog.color.xyz, fogValue);
diff --git a/files/shaders/objects_vertex.glsl b/files/shaders/objects_vertex.glsl
index e140cd6ad..398156b98 100644
--- a/files/shaders/objects_vertex.glsl
+++ b/files/shaders/objects_vertex.glsl
@@ -45,6 +45,8 @@ varying vec4 passColor;
 varying vec3 passViewPos;
 varying vec3 passNormal;
 
+varying vec4 shadowSpaceCoords;
+
 #include "lighting.glsl"
 
 void main(void)
@@ -99,4 +101,8 @@ void main(void)
 #endif
     passViewPos = viewPos.xyz;
     passNormal = gl_Normal.xyz;
+
+	// This matrix has the opposite handedness to the others used here, so multiplication must have the vector to the left. Alternatively it could be transposed after construction, but that's extra work for the GPU just to make the code look a tiny bit cleaner.
+	mat4 eyePlaneMat = mat4(gl_EyePlaneS[1], gl_EyePlaneT[1], gl_EyePlaneR[1], gl_EyePlaneQ[1]);
+	shadowSpaceCoords = viewPos * eyePlaneMat;
 }
diff --git a/files/shaders/terrain_fragment.glsl b/files/shaders/terrain_fragment.glsl
index 134e838c0..cca9a57dd 100644
--- a/files/shaders/terrain_fragment.glsl
+++ b/files/shaders/terrain_fragment.glsl
@@ -1,5 +1,7 @@
 #version 120
 
+#define FRAGMENT
+
 varying vec2 uv;
 
 uniform sampler2D diffuseMap;
@@ -24,6 +26,9 @@ varying vec4 passColor;
 varying vec3 passViewPos;
 varying vec3 passNormal;
 
+uniform sampler2DShadow shadowTexture;
+varying vec4 shadowSpaceCoords;
+
 #include "lighting.glsl"
 #include "parallax.glsl"
 
@@ -64,10 +69,12 @@ void main()
     gl_FragData[0].a *= texture2D(blendMap, blendMapUV).a;
 #endif
 
+	float shadowing = shadow2DProj(shadowTexture, shadowSpaceCoords).r;
+
 #if !PER_PIXEL_LIGHTING
-    gl_FragData[0] *= lighting;
+    gl_FragData[0] *= lighting * shadowing;
 #else
-    gl_FragData[0] *= doLighting(passViewPos, normalize(viewNormal), passColor);
+    gl_FragData[0] *= doLighting(passViewPos, normalize(viewNormal), passColor, shadowing);
 #endif
 
 #if @specularMap
@@ -78,7 +85,7 @@ void main()
     vec3 matSpec = gl_FrontMaterial.specular.xyz;
 #endif
 
-    gl_FragData[0].xyz += getSpecular(normalize(viewNormal), normalize(passViewPos), shininess, matSpec);
+    gl_FragData[0].xyz += getSpecular(normalize(viewNormal), normalize(passViewPos), shininess, matSpec) * shadowing;
 
     float fogValue = clamp((depth - gl_Fog.start) * gl_Fog.scale, 0.0, 1.0);
     gl_FragData[0].xyz = mix(gl_FragData[0].xyz, gl_Fog.color.xyz, fogValue);
diff --git a/files/shaders/terrain_vertex.glsl b/files/shaders/terrain_vertex.glsl
index e2a180153..1bc2337f8 100644
--- a/files/shaders/terrain_vertex.glsl
+++ b/files/shaders/terrain_vertex.glsl
@@ -13,6 +13,8 @@ varying vec4 passColor;
 varying vec3 passViewPos;
 varying vec3 passNormal;
 
+varying vec4 shadowSpaceCoords;
+
 #include "lighting.glsl"
 
 void main(void)
@@ -33,4 +35,8 @@ void main(void)
     passViewPos = viewPos.xyz;
 
     uv = gl_MultiTexCoord0.xy;
+
+	// This matrix has the opposite handedness to the others used here, so multiplication must have the vector to the left. Alternatively it could be transposed after construction, but that's extra work for the GPU just to make the code look a tiny bit cleaner.
+	mat4 eyePlaneMat = mat4(gl_EyePlaneS[1], gl_EyePlaneT[1], gl_EyePlaneR[1], gl_EyePlaneQ[1]);
+	shadowSpaceCoords = viewPos * eyePlaneMat;
 }