2 files changed, 131 insertions, 70 deletions

diff --git a/client/shaders/nodes_shader/opengl_fragment.glsl b/client/shaders/nodes_shader/opengl_fragment.glsl
index 87ef9af7d..8110f6fd3 100644
--- a/client/shaders/nodes_shader/opengl_fragment.glsl
+++ b/client/shaders/nodes_shader/opengl_fragment.glsl
@@ -1,5 +1,6 @@
 uniform sampler2D baseTexture;
 
+uniform vec3 dayLight;
 uniform vec4 skyBgColor;
 uniform float fogDistance;
 uniform vec3 eyePosition;
@@ -15,10 +16,15 @@ uniform float animationTimer;
 	uniform float f_textureresolution;
 	uniform mat4 m_ShadowViewProj;
 	uniform float f_shadowfar;
-	varying float normalOffsetScale;
+	uniform float f_shadow_strength;
+	uniform vec4 CameraPos;
+	uniform float xyPerspectiveBias0;
+	uniform float xyPerspectiveBias1;
+	
 	varying float adj_shadow_strength;
 	varying float cosLight;
 	varying float f_normal_length;
+	varying vec3 shadow_position;
 #endif
 
 
@@ -42,23 +48,7 @@ varying float nightRatio;
 const float fogStart = FOG_START;
 const float fogShadingParameter = 1.0 / ( 1.0 - fogStart);
 
-
-
 #ifdef ENABLE_DYNAMIC_SHADOWS
-const float bias0 = 0.9;
-const float zPersFactor = 0.5;
-const float bias1 = 1.0 - bias0 + 1e-6;
-
-vec4 getPerspectiveFactor(in vec4 shadowPosition)
-{
-
-	float pDistance = length(shadowPosition.xy);
-	float pFactor = pDistance * bias0 + bias1;
-
-	shadowPosition.xyz *= vec3(vec2(1.0 / pFactor), zPersFactor);
-
-	return shadowPosition;
-}
 
 // assuming near is always 1.0
 float getLinearDepth()
@@ -68,16 +58,7 @@ float getLinearDepth()
 
 vec3 getLightSpacePosition()
 {
-	vec4 pLightSpace;
-	// some drawtypes have zero normals, so we need to handle it :(
-	#if DRAW_TYPE == NDT_PLANTLIKE
-	pLightSpace = m_ShadowViewProj * vec4(worldPosition, 1.0);
-	#else
-	float offsetScale = (0.0057 * getLinearDepth() + normalOffsetScale);
-	pLightSpace = m_ShadowViewProj * vec4(worldPosition + offsetScale * normalize(vNormal), 1.0);
-	#endif
-	pLightSpace = getPerspectiveFactor(pLightSpace);
-	return pLightSpace.xyz * 0.5 + 0.5;
+	return shadow_position * 0.5 + 0.5;
 }
 // custom smoothstep implementation because it's not defined in glsl1.2
 // https://docs.gl/sl4/smoothstep
@@ -170,13 +151,13 @@ float getHardShadowDepth(sampler2D shadowsampler, vec2 smTexCoord, float realDis
 
 float getBaseLength(vec2 smTexCoord)
 {
-	float l = length(2.0 * smTexCoord.xy - 1.0);     // length in texture coords
-	return bias1 / (1.0 / l - bias0); 				 // return to undistorted coords
+	float l = length(2.0 * smTexCoord.xy - 1.0 - CameraPos.xy);     // length in texture coords
+	return xyPerspectiveBias1 / (1.0 / l - xyPerspectiveBias0); 				 // return to undistorted coords
 }
 
 float getDeltaPerspectiveFactor(float l)
 {
-	return 0.1 / (bias0 * l + bias1);                      // original distortion factor, divided by 10
+	return 0.04 * pow(512.0 / f_textureresolution, 0.4) / (xyPerspectiveBias0 * l + xyPerspectiveBias1);                      // original distortion factor, divided by 10
 }
 
 float getPenumbraRadius(sampler2D shadowsampler, vec2 smTexCoord, float realDistance, float multiplier)
@@ -185,6 +166,9 @@ float getPenumbraRadius(sampler2D shadowsampler, vec2 smTexCoord, float realDist
 	float perspectiveFactor;
 
 	// Return fast if sharp shadows are requested
+	if (PCFBOUND == 0.0)
+		return 0.0;
+
 	if (SOFTSHADOWRADIUS <= 1.0) {
 		perspectiveFactor = getDeltaPerspectiveFactor(baseLength);
 		return max(2 * length(smTexCoord.xy) * 2048 / f_textureresolution / pow(perspectiveFactor, 3), SOFTSHADOWRADIUS);
@@ -479,36 +463,59 @@ void main(void)
 	vec4 col = vec4(color.rgb * varColor.rgb, 1.0);
 
 #ifdef ENABLE_DYNAMIC_SHADOWS
-	float shadow_int = 0.0;
-	vec3 shadow_color = vec3(0.0, 0.0, 0.0);
-	vec3 posLightSpace = getLightSpacePosition();
+	if (f_shadow_strength > 0.0) {
+		float shadow_int = 0.0;
+		vec3 shadow_color = vec3(0.0, 0.0, 0.0);
+		vec3 posLightSpace = getLightSpacePosition();
 
-	float distance_rate = (1 - pow(clamp(2.0 * length(posLightSpace.xy - 0.5),0.0,1.0), 20.0));
-	float f_adj_shadow_strength = max(adj_shadow_strength-mtsmoothstep(0.9,1.1,  posLightSpace.z  ),0.0);
+		float distance_rate = (1.0 - pow(clamp(2.0 * length(posLightSpace.xy - 0.5),0.0,1.0), 10.0));
+		if (max(abs(posLightSpace.x - 0.5), abs(posLightSpace.y - 0.5)) > 0.5)
+			distance_rate = 0.0;
+		float f_adj_shadow_strength = max(adj_shadow_strength-mtsmoothstep(0.9,1.1,  posLightSpace.z),0.0);
+
+		if (distance_rate > 1e-7) {
 
-	if (distance_rate > 1e-7) {
-	
 #ifdef COLORED_SHADOWS
-		vec4 visibility = getShadowColor(ShadowMapSampler, posLightSpace.xy, posLightSpace.z);
-		shadow_int = visibility.r;
-		shadow_color = visibility.gba;
+			vec4 visibility;
+			if (cosLight > 0.0 || f_normal_length < 1e-3)
+				visibility = getShadowColor(ShadowMapSampler, posLightSpace.xy, posLightSpace.z);
+			else
+				visibility = vec4(1.0, 0.0, 0.0, 0.0);
+			shadow_int = visibility.r;
+			shadow_color = visibility.gba;
 #else
-		shadow_int = getShadow(ShadowMapSampler, posLightSpace.xy, posLightSpace.z);
+			if (cosLight > 0.0 || f_normal_length < 1e-3)
+				shadow_int = getShadow(ShadowMapSampler, posLightSpace.xy, posLightSpace.z);
+			else
+				shadow_int = 1.0;
 #endif
-		shadow_int *= distance_rate;
-		shadow_int *= 1.0 - nightRatio;
+			shadow_int *= distance_rate;
+			shadow_int = clamp(shadow_int, 0.0, 1.0);
 
+		}
 
-	}
+		// turns out that nightRatio falls off much faster than
+		// actual brightness of artificial light in relation to natual light.
+		// Power ratio was measured on torches in MTG (brightness = 14).
+		float adjusted_night_ratio = pow(max(0.0, nightRatio), 0.6);
+
+		// Apply self-shadowing when light falls at a narrow angle to the surface
+		// Cosine of the cut-off angle.
+		const float self_shadow_cutoff_cosine = 0.035;
+		if (f_normal_length != 0 && cosLight < self_shadow_cutoff_cosine) {
+			shadow_int = max(shadow_int, 1 - clamp(cosLight, 0.0, self_shadow_cutoff_cosine)/self_shadow_cutoff_cosine);
+			shadow_color = mix(vec3(0.0), shadow_color, min(cosLight, self_shadow_cutoff_cosine)/self_shadow_cutoff_cosine);
+		}
 
-	if (f_normal_length != 0 && cosLight < 0.035) {
-		shadow_int = max(shadow_int, min(clamp(1.0-nightRatio, 0.0, 1.0), 1 - clamp(cosLight, 0.0, 0.035)/0.035));
-	}
+		shadow_int *= f_adj_shadow_strength;
 
-	shadow_int = 1.0 - (shadow_int * f_adj_shadow_strength);
-	
-	col.rgb = mix(shadow_color,col.rgb,shadow_int)*shadow_int;
-	// col.r = 0.5 * clamp(getPenumbraRadius(ShadowMapSampler, posLightSpace.xy, posLightSpace.z, 1.0) / SOFTSHADOWRADIUS, 0.0, 1.0) + 0.5 * col.r;
+		// calculate fragment color from components:
+		col.rgb =
+				adjusted_night_ratio * col.rgb + // artificial light
+				(1.0 - adjusted_night_ratio) * ( // natural light
+						col.rgb * (1.0 - shadow_int * (1.0 - shadow_color)) +  // filtered texture color
+						dayLight * shadow_color * shadow_int);                 // reflected filtered sunlight/moonlight
+	}
 #endif
 
 #if ENABLE_TONE_MAPPING
@@ -528,6 +535,6 @@ void main(void)
 		- fogShadingParameter * length(eyeVec) / fogDistance, 0.0, 1.0);
 	col = mix(skyBgColor, col, clarity);
 	col = vec4(col.rgb, base.a);
-	
+
 	gl_FragColor = col;
 }
diff --git a/client/shaders/nodes_shader/opengl_vertex.glsl b/client/shaders/nodes_shader/opengl_vertex.glsl
index d316930b2..3ea0faa36 100644
--- a/client/shaders/nodes_shader/opengl_vertex.glsl
+++ b/client/shaders/nodes_shader/opengl_vertex.glsl
@@ -32,10 +32,13 @@ centroid varying vec2 varTexCoord;
 	uniform float f_shadowfar;
 	uniform float f_shadow_strength;
 	uniform float f_timeofday;
+	uniform vec4 CameraPos;
+
 	varying float cosLight;
 	varying float normalOffsetScale;
 	varying float adj_shadow_strength;
 	varying float f_normal_length;
+	varying vec3 shadow_position;
 #endif
 
 
@@ -45,8 +48,38 @@ varying float nightRatio;
 const vec3 artificialLight = vec3(1.04, 1.04, 1.04);
 const float e = 2.718281828459;
 const float BS = 10.0;
+uniform float xyPerspectiveBias0;
+uniform float xyPerspectiveBias1;
+uniform float zPerspectiveBias;
 
 #ifdef ENABLE_DYNAMIC_SHADOWS
+
+vec4 getRelativePosition(in vec4 position)
+{
+	vec2 l = position.xy - CameraPos.xy;
+	vec2 s = l / abs(l);
+	s = (1.0 - s * CameraPos.xy);
+	l /= s;
+	return vec4(l, s);
+}
+
+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;
+}
+
 // custom smoothstep implementation because it's not defined in glsl1.2
 // https://docs.gl/sl4/smoothstep
 float mtsmoothstep(in float edge0, in float edge1, in float x)
@@ -193,24 +226,45 @@ void main(void)
 	varColor = clamp(color, 0.0, 1.0);
 
 #ifdef ENABLE_DYNAMIC_SHADOWS
-	vec3 nNormal = normalize(vNormal);
-	cosLight = dot(nNormal, -v_LightDirection);
-	float texelSize = 767.0 / f_textureresolution;
-	float slopeScale = clamp(1.0 - abs(cosLight), 0.0, 1.0);
-	normalOffsetScale = texelSize * slopeScale;
-	
-	if (f_timeofday < 0.2) {
-		adj_shadow_strength = f_shadow_strength * 0.5 *
-			(1.0 - mtsmoothstep(0.18, 0.2, f_timeofday));
-	} else if (f_timeofday >= 0.8) {
-		adj_shadow_strength = f_shadow_strength * 0.5 *
-			mtsmoothstep(0.8, 0.83, f_timeofday);
-	} else {
-		adj_shadow_strength = f_shadow_strength *
-			mtsmoothstep(0.20, 0.25, f_timeofday) *
-			(1.0 - mtsmoothstep(0.7, 0.8, f_timeofday));
+	if (f_shadow_strength > 0.0) {
+		vec3 nNormal;
+		f_normal_length = length(vNormal);
+
+		/* normalOffsetScale is in world coordinates (1/10th of a meter)
+		   z_bias is in light space coordinates */
+		float normalOffsetScale, z_bias;
+		float pFactor = getPerspectiveFactor(getRelativePosition(m_ShadowViewProj * mWorld * inVertexPosition));
+		if (f_normal_length > 0.0) {
+			nNormal = normalize(vNormal);
+			cosLight = dot(nNormal, -v_LightDirection);
+			float sinLight = pow(1 - pow(cosLight, 2.0), 0.5);
+			normalOffsetScale = 2.0 * pFactor * pFactor * sinLight * min(f_shadowfar, 500.0) / 
+					xyPerspectiveBias1 / f_textureresolution;
+			z_bias = 1.0 * sinLight / cosLight;
+		}
+		else {
+			nNormal = vec3(0.0);
+			cosLight = clamp(dot(v_LightDirection, normalize(vec3(v_LightDirection.x, 0.0, v_LightDirection.z))), 1e-2, 1.0);
+			float sinLight = pow(1 - pow(cosLight, 2.0), 0.5);
+			normalOffsetScale = 0.0;
+			z_bias = 3.6e3 * sinLight / cosLight;
+		}
+		z_bias *= pFactor * pFactor / f_textureresolution / f_shadowfar;
+
+		shadow_position = applyPerspectiveDistortion(m_ShadowViewProj * mWorld * (inVertexPosition + vec4(normalOffsetScale * nNormal, 0.0))).xyz;
+		shadow_position.z -= z_bias;
+
+		if (f_timeofday < 0.2) {
+			adj_shadow_strength = f_shadow_strength * 0.5 *
+				(1.0 - mtsmoothstep(0.18, 0.2, f_timeofday));
+		} else if (f_timeofday >= 0.8) {
+			adj_shadow_strength = f_shadow_strength * 0.5 *
+				mtsmoothstep(0.8, 0.83, f_timeofday);
+		} else {
+			adj_shadow_strength = f_shadow_strength *
+				mtsmoothstep(0.20, 0.25, f_timeofday) *
+				(1.0 - mtsmoothstep(0.7, 0.8, f_timeofday));
+		}
 	}
-	f_normal_length = length(vNormal);
 #endif
-
 }