Bloom (#12791)

Adds configurable light exposure control and bloom effect (light bleeding) with client-side settings.

7 files changed, 166 insertions, 7 deletions

diff --git a/client/shaders/blur_h/opengl_fragment.glsl b/client/shaders/blur_h/opengl_fragment.glsl
new file mode 100644
index 000000000..c5818f9d8
--- /dev/null
+++ b/client/shaders/blur_h/opengl_fragment.glsl
@@ -0,0 +1,29 @@
+#define rendered texture0
+
+uniform sampler2D rendered;
+uniform vec2 texelSize0;
+uniform mediump float bloomRadius = 3.0;
+
+#ifdef GL_ES
+varying mediump vec2 varTexCoord;
+#else
+centroid varying vec2 varTexCoord;
+#endif
+
+void main(void)
+{
+	// kernel distance and linear size
+	mediump float n = 2. * bloomRadius + 1.;
+
+	vec2 uv = varTexCoord.st - vec2(bloomRadius * texelSize0.x, 0.);
+	vec4 color = vec4(0.);
+	mediump float sum = 0.;
+	for (mediump float i = 0.; i < n; i++) {
+		mediump float weight = pow(1. - (abs(i / bloomRadius - 1.)), 1.3);
+		color += texture2D(rendered, uv).rgba * weight;
+		sum += weight;
+		uv += vec2(texelSize0.x, 0.);
+	}
+	color /= sum;
+	gl_FragColor = vec4(color.rgb, 1.0); // force full alpha to avoid holes in the image.
+}
diff --git a/client/shaders/blur_h/opengl_vertex.glsl b/client/shaders/blur_h/opengl_vertex.glsl
new file mode 100644
index 000000000..12692c296
--- /dev/null
+++ b/client/shaders/blur_h/opengl_vertex.glsl
@@ -0,0 +1,11 @@
+#ifdef GL_ES
+varying mediump vec2 varTexCoord;
+#else
+centroid varying vec2 varTexCoord;
+#endif
+
+void main(void)
+{
+	varTexCoord.st = inTexCoord0.st;
+	gl_Position = inVertexPosition;
+}
diff --git a/client/shaders/blur_v/opengl_fragment.glsl b/client/shaders/blur_v/opengl_fragment.glsl
new file mode 100644
index 000000000..6820ca10d
--- /dev/null
+++ b/client/shaders/blur_v/opengl_fragment.glsl
@@ -0,0 +1,29 @@
+#define rendered texture0
+
+uniform sampler2D rendered;
+uniform vec2 texelSize0;
+uniform mediump float bloomRadius = 3.0;
+
+#ifdef GL_ES
+varying mediump vec2 varTexCoord;
+#else
+centroid varying vec2 varTexCoord;
+#endif
+
+void main(void)
+{
+	// kernel distance and linear size
+	mediump float n = 2. * bloomRadius + 1.;
+
+	vec2 uv = varTexCoord.st - vec2(0., bloomRadius * texelSize0.y);
+	vec4 color = vec4(0.);
+	mediump float sum = 0.;
+	for (mediump float i = 0.; i < n; i++) {
+		mediump float weight = pow(1. - (abs(i / bloomRadius - 1.)), 1.3);
+		color += texture2D(rendered, uv).rgba * weight;
+		sum += weight;
+		uv += vec2(0., texelSize0.y);
+	}
+	color /= sum;
+	gl_FragColor = vec4(color.rgb, 1.0); // force full alpha to avoid holes in the image.
+}
diff --git a/client/shaders/blur_v/opengl_vertex.glsl b/client/shaders/blur_v/opengl_vertex.glsl
new file mode 100644
index 000000000..12692c296
--- /dev/null
+++ b/client/shaders/blur_v/opengl_vertex.glsl
@@ -0,0 +1,11 @@
+#ifdef GL_ES
+varying mediump vec2 varTexCoord;
+#else
+centroid varying vec2 varTexCoord;
+#endif
+
+void main(void)
+{
+	varTexCoord.st = inTexCoord0.st;
+	gl_Position = inVertexPosition;
+}
diff --git a/client/shaders/extract_bloom/opengl_fragment.glsl b/client/shaders/extract_bloom/opengl_fragment.glsl
new file mode 100644
index 000000000..8c25328ac
--- /dev/null
+++ b/client/shaders/extract_bloom/opengl_fragment.glsl
@@ -0,0 +1,21 @@
+#define rendered texture0
+
+uniform sampler2D rendered;
+uniform mediump float exposureFactor = 2.5;
+uniform float bloomLuminanceThreshold = 1.0;
+
+#ifdef GL_ES
+varying mediump vec2 varTexCoord;
+#else
+centroid varying vec2 varTexCoord;
+#endif
+
+
+void main(void)
+{
+	vec2 uv = varTexCoord.st;
+	vec4 color = texture2D(rendered, uv).rgba;
+	// translate to linear colorspace (approximate)
+	color.rgb = pow(color.rgb, vec3(2.2)) * exposureFactor;
+	gl_FragColor = vec4(color.rgb, 1.0); // force full alpha to avoid holes in the image.
+}
diff --git a/client/shaders/extract_bloom/opengl_vertex.glsl b/client/shaders/extract_bloom/opengl_vertex.glsl
new file mode 100644
index 000000000..12692c296
--- /dev/null
+++ b/client/shaders/extract_bloom/opengl_vertex.glsl
@@ -0,0 +1,11 @@
+#ifdef GL_ES
+varying mediump vec2 varTexCoord;
+#else
+centroid varying vec2 varTexCoord;
+#endif
+
+void main(void)
+{
+	varTexCoord.st = inTexCoord0.st;
+	gl_Position = inVertexPosition;
+}
diff --git a/client/shaders/second_stage/opengl_fragment.glsl b/client/shaders/second_stage/opengl_fragment.glsl
index 965450fcb..b929b33b4 100644
--- a/client/shaders/second_stage/opengl_fragment.glsl
+++ b/client/shaders/second_stage/opengl_fragment.glsl
@@ -1,6 +1,10 @@
-uniform sampler2D baseTexture;
+#define rendered texture0
+#define bloom texture1
 
-#define rendered baseTexture
+uniform sampler2D rendered;
+uniform sampler2D bloom;
+uniform mediump float exposureFactor = 2.5;
+uniform lowp float bloomIntensity = 1.0;
 
 #ifdef GL_ES
 varying mediump vec2 varTexCoord;
@@ -8,6 +12,24 @@ varying mediump vec2 varTexCoord;
 centroid varying vec2 varTexCoord;
 #endif
 
+#if ENABLE_BLOOM
+
+vec4 applyBloom(vec4 color, vec2 uv)
+{
+	float bias = bloomIntensity;
+	vec4 bloom = texture2D(bloom, uv);
+#if ENABLE_BLOOM_DEBUG
+	if (uv.x > 0.5 && uv.y < 0.5)
+		return vec4(bloom.rgb, color.a);
+	if (uv.x < 0.5)
+		return color;
+#endif
+	color.rgb = mix(color.rgb, bloom.rgb, bias);
+	return color;
+}
+
+#endif
+
 #if ENABLE_TONE_MAPPING
 
 /* Hable's UC2 Tone mapping parameters
@@ -28,15 +50,13 @@ vec3 uncharted2Tonemap(vec3 x)
 
 vec4 applyToneMapping(vec4 color)
 {
-	color = vec4(pow(color.rgb, vec3(2.2)), color.a);
-	const float gamma = 1.6;
-	const float exposureBias = 5.5;
+	const float exposureBias = 2.0;
 	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);
+	return color;
 }
 #endif
 
@@ -45,9 +65,36 @@ void main(void)
 	vec2 uv = varTexCoord.st;
 	vec4 color = texture2D(rendered, uv).rgba;
 
+	// translate to linear colorspace (approximate)
+	color.rgb = pow(color.rgb, vec3(2.2));
+
+#if ENABLE_BLOOM_DEBUG
+	if (uv.x > 0.5 || uv.y > 0.5)
+#endif
+	{
+		color.rgb *= exposureFactor;
+	}
+
+
+#if ENABLE_BLOOM
+	color = applyBloom(color, uv);
+#endif
+
+#if ENABLE_BLOOM_DEBUG
+	if (uv.x > 0.5 || uv.y > 0.5)
+#endif
+	{
 #if ENABLE_TONE_MAPPING
-	color = applyToneMapping(color);
+		color = applyToneMapping(color);
+#else
+		color.rgb /= 2.5; // default exposure factor, see also RenderingEngine::DEFAULT_EXPOSURE_FACTOR;
 #endif
+	}
+
+	color.rgb = clamp(color.rgb, vec3(0.), vec3(1.));
+
+	// return to sRGB colorspace (approximate)
+	color.rgb = pow(color.rgb, vec3(1.0 / 2.2));
 
 	gl_FragColor = vec4(color.rgb, 1.0); // force full alpha to avoid holes in the image.
 }