2 files changed, 53 insertions, 19 deletions
diff --git a/client/shaders/shadow_shaders/pass1_trans_vertex.glsl b/client/shaders/shadow_shaders/pass1_trans_vertex.glsl
index 0a9efe450..244d2562a 100644
--- a/client/shaders/shadow_shaders/pass1_trans_vertex.glsl
+++ b/client/shaders/shadow_shaders/pass1_trans_vertex.glsl
@@ -1,28 +1,45 @@
 uniform mat4 LightMVP; // world matrix
+uniform vec4 CameraPos;
 varying vec4 tPos;
 #ifdef COLORED_SHADOWS
 varying vec3 varColor;
 #endif
 
-const float bias0 = 0.9;
-const float zPersFactor = 0.5;
-const float bias1 = 1.0 - bias0 + 1e-6;
+uniform float xyPerspectiveBias0;
+uniform float xyPerspectiveBias1;
+uniform float zPerspectiveBias;
 
-vec4 getPerspectiveFactor(in vec4 shadowPosition)
+vec4 getRelativePosition(in vec4 position)
 {
-	float pDistance = length(shadowPosition.xy);
-	float pFactor = pDistance * bias0 + bias1;
-	shadowPosition.xyz *= vec3(vec2(1.0 / pFactor), zPersFactor);
+	vec2 l = position.xy - CameraPos.xy;
+	vec2 s = l / abs(l);
+	s = (1.0 - s * CameraPos.xy);
+	l /= s;
+	return vec4(l, s);
+}
 
-	return shadowPosition;
+float getPerspectiveFactor(in vec4 relativePosition)
+{
+	float pDistance = length(relativePosition.xy);
+	float pFactor = pDistance * xyPerspectiveBias0 + xyPerspectiveBias1;
+	return pFactor;
 }
 
+vec4 applyPerspectiveDistortion(in vec4 position)
+{
+	vec4 l = getRelativePosition(position);
+	float pFactor = getPerspectiveFactor(l);
+	l.xy /= pFactor;
+	position.xy = l.xy * l.zw + CameraPos.xy;
+	position.z *= zPerspectiveBias;
+	return position;
+}
 
 void main()
 {
 	vec4 pos = LightMVP * gl_Vertex;
 
-	tPos = getPerspectiveFactor(LightMVP * gl_Vertex);
+	tPos = applyPerspectiveDistortion(LightMVP * gl_Vertex);
 
 	gl_Position = vec4(tPos.xyz, 1.0);
 	gl_TexCoord[0].st = gl_MultiTexCoord0.st;
diff --git a/client/shaders/shadow_shaders/pass1_vertex.glsl b/client/shaders/shadow_shaders/pass1_vertex.glsl
index a6d8b3db8..1dceb93c6 100644
--- a/client/shaders/shadow_shaders/pass1_vertex.glsl
+++ b/client/shaders/shadow_shaders/pass1_vertex.glsl
@@ -1,26 +1,43 @@
 uniform mat4 LightMVP; // world matrix
+uniform vec4 CameraPos; // camera position
 varying vec4 tPos;
 
-const float bias0 = 0.9;
-const float zPersFactor = 0.5;
-const float bias1 = 1.0 - bias0 + 1e-6;
+uniform float xyPerspectiveBias0;
+uniform float xyPerspectiveBias1;
+uniform float zPerspectiveBias;
 
-vec4 getPerspectiveFactor(in vec4 shadowPosition)
+vec4 getRelativePosition(in vec4 position)
 {
-	float pDistance = length(shadowPosition.xy);
-	float pFactor = pDistance * bias0 + bias1;
-	shadowPosition.xyz *= vec3(vec2(1.0 / pFactor), zPersFactor);
+	vec2 l = position.xy - CameraPos.xy;
+	vec2 s = l / abs(l);
+	s = (1.0 - s * CameraPos.xy);
+	l /= s;
+	return vec4(l, s);
+}
 
-	return shadowPosition;
+float getPerspectiveFactor(in vec4 relativePosition)
+{
+	float pDistance = length(relativePosition.xy);
+	float pFactor = pDistance * xyPerspectiveBias0 + xyPerspectiveBias1;
+	return pFactor;
 }
 
+vec4 applyPerspectiveDistortion(in vec4 position)
+{
+	vec4 l = getRelativePosition(position);
+	float pFactor = getPerspectiveFactor(l);
+	l.xy /= pFactor;
+	position.xy = l.xy * l.zw + CameraPos.xy;
+	position.z *= zPerspectiveBias;
+	return position;
+}
 
 void main()
 {
 	vec4 pos = LightMVP * gl_Vertex;
 
-	tPos = getPerspectiveFactor(pos);
+	tPos = applyPerspectiveDistortion(pos);
 
 	gl_Position = vec4(tPos.xyz, 1.0);
-	gl_TexCoord[0].st = gl_MultiTexCoord0.st;
+	gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0;
 }