From 3c3d925e5a7bdf426429123e17d2345f282fa271 Mon Sep 17 00:00:00 2001
From: Recrown <yunyangdeng@gmail.com>
Date: Mon, 3 Sep 2018 22:52:17 -0500
Subject: [PATCH] combination fragment shader now uses exposure

---
 android/assets/shaders/combine.fsh            | 17 ++++++++-------
 android/assets/shaders/gaussian_blur.fsh      |  4 +---
 .../graphics/shaders/BloomShader.java         | 21 +------------------
 3 files changed, 12 insertions(+), 30 deletions(-)

diff --git a/android/assets/shaders/combine.fsh b/android/assets/shaders/combine.fsh
index ef8d7f3..6dbd790 100755
--- a/android/assets/shaders/combine.fsh
+++ b/android/assets/shaders/combine.fsh
@@ -11,15 +11,18 @@ varying vec2 vTexCoord;
 
 uniform sampler2D u_texture;
 uniform sampler2D u_texture1;
+uniform float exposure;
 
 void main() {
-	vec4 origColor = texture2D(u_texture, vTexCoord);
-	vec4 blurredColor = texture2D(u_texture1, vTexCoord);
+	vec3 origColor = texture2D(u_texture, vTexCoord).rgb;
+	vec3 blurredColor = texture2D(u_texture1, vTexCoord).rgb;
 	
-	vec4 result;
-	result = origColor + blurredColor;
-	result.a = vColor.a;
-	result.rgb *= vColor.rgb;
-	gl_FragColor = result;
+    const float gamma = 2.2;
+    origColor += blurredColor; // additive blending
+    // tone mapping
+    vec3 result = vec3(1.0) - exp(-origColor * exposure);
+    // also gamma correct while we're at it       
+    result = pow(result, vec3(1.0 / gamma));
+    gl_FragColor = vec4(result, 1.0);
 
 }
diff --git a/android/assets/shaders/gaussian_blur.fsh b/android/assets/shaders/gaussian_blur.fsh
index 98ace20..6984e1d 100755
--- a/android/assets/shaders/gaussian_blur.fsh
+++ b/android/assets/shaders/gaussian_blur.fsh
@@ -34,9 +34,7 @@ void main() {
 	sum += texture2D(u_texture, vec2(tc.x - 3.0*blur*hstep, tc.y - 3.0*blur*vstep)) * 0.072994;
 	sum += texture2D(u_texture, vec2(tc.x - 2.0*blur*hstep, tc.y - 2.0*blur*vstep)) * 0.121281;
 	sum += texture2D(u_texture, vec2(tc.x - 1.0*blur*hstep, tc.y - 1.0*blur*vstep)) * 0.164472;
-	
-	sum += texture2D(u_texture, vec2(tc.x, tc.y)) * 0.182049;
-	
+		
 	sum += texture2D(u_texture, vec2(tc.x + 1.0*blur*hstep, tc.y + 1.0*blur*vstep)) * 0.164472;
 	sum += texture2D(u_texture, vec2(tc.x + 2.0*blur*hstep, tc.y + 2.0*blur*vstep)) * 0.121281;
 	sum += texture2D(u_texture, vec2(tc.x + 3.0*blur*hstep, tc.y + 3.0*blur*vstep)) * 0.072994;
diff --git a/core/src/zero1hd/rhythmbullet/graphics/shaders/BloomShader.java b/core/src/zero1hd/rhythmbullet/graphics/shaders/BloomShader.java
index d0d01c9..261c798 100755
--- a/core/src/zero1hd/rhythmbullet/graphics/shaders/BloomShader.java
+++ b/core/src/zero1hd/rhythmbullet/graphics/shaders/BloomShader.java
@@ -69,6 +69,7 @@ public class BloomShader implements Disposable {
 
 		combineShader.begin();
 		combineShader.setUniformi("u_texture1", 1);
+		combineShader.setUniformf("exposure", 0.5f);
 		combineShader.end();
 		
 		gaussianBlurShader.begin();
@@ -124,26 +125,6 @@ public class BloomShader implements Disposable {
 		screenBatch.flush();
 		vBlur.end();
 		
-		if (bloomLevel > 2) {
-//			Horizontal gaussian blur
-			fboRegion.setTexture(vBlur.getColorBufferTexture());
-			hBlur.begin();
-			gaussianBlurShader.setUniformf("radius", 1.1f);
-			gaussianBlurShader.setUniformi("pass", 0);
-			screenBatch.draw(fboRegion, 0f, 0f, width, height);
-			screenBatch.flush();
-			hBlur.end();
-			
-			
-//			//Vertical gaussian blur
-			fboRegion.setTexture(hBlur.getColorBufferTexture());
-			vBlur.begin();
-			gaussianBlurShader.setUniformi("pass", 1);
-			screenBatch.draw(fboRegion, 0f, 0f, width, height);
-			screenBatch.flush();
-			vBlur.end();
-		}
-
 		Gdx.gl.glClearColor(0f, 0f, 0f, 1f);
 		Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
 		screenBatch.setShader(combineShader);