Filmic HDR tone mapping

minetest · Feb 9, 2016 · eb3840a · eb3840a
1 parent 180893e
commit eb3840a
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Showing 6 changed files with 101 additions and 14 deletions.
diff --git a/builtin/settingtypes.txt b/builtin/settingtypes.txt
@@ -326,6 +326,11 @@ fsaa (FSAA) enum 0 0,1,2,4,8,16
 #    Thy only work with the OpenGL video backend.
 enable_shaders (Shaders) bool true
 
+[****Tone Mapping]
+
+#    Enables filmic tone mapping
+tone_mapping (Filmic tone mapping) bool false
+
 [****Bumpmapping]
 
 #    Enables bumpmapping for textures. Normalmaps need to be supplied by the texture pack

diff --git a/client/shaders/nodes_shader/opengl_fragment.glsl b/client/shaders/nodes_shader/opengl_fragment.glsl
@@ -20,6 +20,38 @@ bool normalTexturePresent = false;
 const float e = 2.718281828459;
 const float BS = 10.0;
 
+#ifdef ENABLE_TONE_MAPPING
+
+/* Hable's UC2 Tone mapping parameters
+	A = 0.22;
+	B = 0.30;
+	C = 0.10;
+	D = 0.20;
+	E = 0.01;
+	F = 0.30;
+	W = 11.2;
+	equation used:  ((x * (A * x + C * B) + D * E) / (x * (A * x + B) + D * F)) - E / F
+*/
+
+vec3 uncharted2Tonemap(vec3 x)
+{
+	return ((x * (0.22 * x + 0.03) + 0.002) / (x * (0.22 * x + 0.3) + 0.06)) - 0.03334;
+}
+
+vec4 applyToneMapping(vec4 color)
+{
+	color = vec4(pow(color.rgb, vec3(2.2)), color.a);
+	const float gamma = 1.6;
+	const float exposureBias = 5.5;
+	color.rgb = uncharted2Tonemap(exposureBias * color.rgb);
+	// Precalculated white_scale from 
+	//vec3 whiteScale = 1.0 / uncharted2Tonemap(vec3(W));
+	vec3 whiteScale = vec3(1.036015346);
+	color.rgb *= whiteScale;
+	return vec4(pow(color.rgb, vec3(1.0 / gamma)), color.a);
+}
+#endif
+
 void get_texture_flags()
 {
 	vec4 flags = texture2D(textureFlags, vec2(0.0, 0.0));
@@ -160,22 +192,26 @@ void main(void)
 	color = base.rgb;
 #endif
 
+	vec4 col = vec4(color.rgb * gl_Color.rgb, 1.0); 
+
 #if MATERIAL_TYPE == TILE_MATERIAL_LIQUID_TRANSPARENT || MATERIAL_TYPE == TILE_MATERIAL_LIQUID_OPAQUE
 	float alpha = gl_Color.a;
-	vec4 col = vec4(color.rgb, alpha);
-	col *= gl_Color;
 	if (fogDistance != 0.0) {
 		float d = max(0.0, min(vPosition.z / fogDistance * 1.5 - 0.6, 1.0));
 		alpha = mix(alpha, 0.0, d);
 	}
-	gl_FragColor = vec4(col.rgb, alpha);
+	col = vec4(col.rgb, alpha);
 #else
-	vec4 col = vec4(color.rgb, base.a);
-	col *= gl_Color;
 	if (fogDistance != 0.0) {
 		float d = max(0.0, min(vPosition.z / fogDistance * 1.5 - 0.6, 1.0));
 		col = mix(col, skyBgColor, d);
 	}
-	gl_FragColor = vec4(col.rgb, base.a);
+	col = vec4(col.rgb, base.a);
+#endif
+
+#ifdef ENABLE_TONE_MAPPING
+	gl_FragColor = applyToneMapping(col);
+#else
+	gl_FragColor = col;
 #endif
 }
diff --git a/client/shaders/water_surface_shader/opengl_fragment.glsl b/client/shaders/water_surface_shader/opengl_fragment.glsl
@@ -22,6 +22,38 @@ bool texSeamless = false;
 const float e = 2.718281828459;
 const float BS = 10.0;
 
+#ifdef ENABLE_TONE_MAPPING
+
+/* Hable's UC2 Tone mapping parameters
+	A = 0.22;
+	B = 0.30;
+	C = 0.10;
+	D = 0.20;
+	E = 0.01;
+	F = 0.30;
+	W = 11.2;
+	equation used:  ((x * (A * x + C * B) + D * E) / (x * (A * x + B) + D * F)) - E / F
+*/
+
+vec3 uncharted2Tonemap(vec3 x)
+{
+	return ((x * (0.22 * x + 0.03) + 0.002) / (x * (0.22 * x + 0.3) + 0.06)) - 0.03334;
+}
+
+vec4 applyToneMapping(vec4 color)
+{
+	color = vec4(pow(color.rgb, vec3(2.2)), color.a);
+	const float gamma = 1.6;
+	const float exposureBias = 5.5;
+	color.rgb = uncharted2Tonemap(exposureBias * color.rgb);
+	// Precalculated white_scale from 
+	//vec3 whiteScale = 1.0 / uncharted2Tonemap(vec3(W));
+	vec3 whiteScale = vec3(1.036015346);
+	color.rgb *= whiteScale;
+	return vec4(pow(color.rgb, vec3(1.0 / gamma)), color.a);
+}
+#endif
+
 void get_texture_flags()
 {
 	vec4 flags = texture2D(textureFlags, vec2(0.0, 0.0));
@@ -116,22 +148,26 @@ vec4 base = texture2D(baseTexture, uv).rgba;
 	color = base.rgb;
 #endif
 
+	vec4 col = vec4(color.rgb * gl_Color.rgb, 1.0); 
+
 #if MATERIAL_TYPE == TILE_MATERIAL_LIQUID_TRANSPARENT || MATERIAL_TYPE == TILE_MATERIAL_LIQUID_OPAQUE
 	float alpha = gl_Color.a;
-	vec4 col = vec4(color.rgb, alpha);
-	col *= gl_Color;
-	if(fogDistance != 0.0){
+	if (fogDistance != 0.0) {
 		float d = max(0.0, min(vPosition.z / fogDistance * 1.5 - 0.6, 1.0));
 		alpha = mix(alpha, 0.0, d);
 	}
-	gl_FragColor = vec4(col.rgb, alpha);
+	col = vec4(col.rgb, alpha);
 #else
-	vec4 col = vec4(color.rgb, base.a);
-	col *= gl_Color;
-	if(fogDistance != 0.0){
+	if (fogDistance != 0.0) {
 		float d = max(0.0, min(vPosition.z / fogDistance * 1.5 - 0.6, 1.0));
 		col = mix(col, skyBgColor, d);
 	}
-	gl_FragColor = vec4(col.rgb, base.a);
+	col = vec4(col.rgb, base.a);
+#endif
+
+#ifdef ENABLE_TONE_MAPPING
+	gl_FragColor = applyToneMapping(col);
+#else
+	gl_FragColor = col;
 #endif
 }
diff --git a/minetest.conf.example b/minetest.conf.example
@@ -353,6 +353,12 @@
 #    type: bool
 # enable_shaders = true
 
+##### Tone mapping
+#    Enables filmic tone mapping.
+#    Requires shaders to be enabled.
+#    type: bool
+# tone_mapping = false
+
 ##### Bumpmapping
 
 #    Enables bumpmapping for textures. Normalmaps need to be supplied by the texture pack

diff --git a/src/defaultsettings.cpp b/src/defaultsettings.cpp
@@ -160,6 +160,7 @@ void set_default_settings(Settings *settings)
 	settings->setDefault("texture_clean_transparent", "false");
 	settings->setDefault("texture_min_size", "64");
 	settings->setDefault("preload_item_visuals", "false");
+	settings->setDefault("tone_mapping", "false");
 	settings->setDefault("enable_bumpmapping", "false");
 	settings->setDefault("enable_parallax_occlusion", "false");
 	settings->setDefault("generate_normalmaps", "false");

diff --git a/src/shader.cpp b/src/shader.cpp
@@ -764,6 +764,9 @@ ShaderInfo generate_shader(std::string name, u8 material_type, u8 drawtype,
 	else
 		shaders_header += "0\n";
 
+	if (g_settings->getBool("tone_mapping"))
+		shaders_header += "#define ENABLE_TONE_MAPPING\n";
+
 	if(pixel_program != "")
 		pixel_program = shaders_header + pixel_program;
 	if(vertex_program != "")