From 3b12a88a76039e9761add05af2805931f4468ba6 Mon Sep 17 00:00:00 2001
From: Valerie <sleeplessval@gmail.com>
Date: Sun, 14 Apr 2024 13:28:52 -0400
Subject: [PATCH] initial implementation of DoF

---
 shaders/composite.fsh      | 10 +++++++---
 shaders/lang/en_US.lang    |  2 ++
 shaders/module/dof.frag    | 19 +++++++++++++++++++
 shaders/shaders.properties |  2 +-
 4 files changed, 29 insertions(+), 4 deletions(-)
 create mode 100644 shaders/module/dof.frag

diff --git a/shaders/composite.fsh b/shaders/composite.fsh
index 345991b..8173208 100644
--- a/shaders/composite.fsh
+++ b/shaders/composite.fsh
@@ -1,5 +1,7 @@
 #version 120
 
+#define pixelSize 2 // the size of pixels [1 2 4 8 16]
+
 #define dithering // whether or not to apply dithering
 #define colorMode 0 // hsv/rgb [0 1]
 
@@ -9,14 +11,14 @@
 
 #define rgbSteps 4 // the number of rgb values to use [2 4 8 16 32 64]
 
-#define pixelSize 2 // the size of pixels [1 2 4 8 16]
-
 uniform sampler2D gcolor;
 uniform sampler2D colortex1;
 uniform float viewWidth, viewHeight;
 
 varying vec2 texcoord;
 
+#include "/module/dof.frag"
+
 // All components are in the range [0…1], including hue.
 vec3 rgb2hsv(vec3 c)
 {
@@ -116,7 +118,9 @@ float dither(float color, float dithersteps) {
 void main() {
     // adjust texture coordinate based on pixel size if needed
 	vec2 newcoord = texcoord;
-	#if pixelSize > 1
+    #ifdef dof
+        newcoord = depthOfField();
+    #elif pixelSize > 1
 		vec2 view = vec2(viewWidth, viewHeight) / float(pixelSize);
 		float offset = (ceil(pixelSize * 0.5) - 0.5) / float(pixelSize);
 		newcoord = (floor(newcoord * view) + offset) / view;
diff --git a/shaders/lang/en_US.lang b/shaders/lang/en_US.lang
index f06b118..b4ab046 100644
--- a/shaders/lang/en_US.lang
+++ b/shaders/lang/en_US.lang
@@ -36,6 +36,8 @@ option.tWarp=Texture Warping
 option.tWarp.comment=Emulates affine texture mapping responsible for warping textures on the PSX
 
 screen.FX=FX
+option.dof=Depth of Field
+option.dof.comment=Downscale out-of-focus objects
 option.worldCurvature=World Curvature
 value.worldCurvature.0=Off
 value.worldCurvature.1=Chunk
diff --git a/shaders/module/dof.frag b/shaders/module/dof.frag
new file mode 100644
index 0000000..18e830f
--- /dev/null
+++ b/shaders/module/dof.frag
@@ -0,0 +1,19 @@
+
+//#define dof
+
+uniform float centerDepthSmooth;
+uniform sampler2D depthtex1;
+
+const float centerDepthSmoothHalfLife = 16f;
+
+vec2 depthOfField() {
+	float depth = texture2D(depthtex1, texcoord).x;
+	float distance = depth - centerDepthSmooth;
+	int stops = min(int(distance * 96), 5);
+
+	float virtualSize = pow(float(pixelSize), 1 + stops);//1 + stops);
+	vec2 view = vec2(viewWidth, viewHeight) / virtualSize;
+	float offset = (ceil(virtualSize * 0.5) - 0.5) / virtualSize;
+	return (floor(texcoord * view) + offset) / view;
+}
+
diff --git a/shaders/shaders.properties b/shaders/shaders.properties
index 8ac1888..5aea619 100644
--- a/shaders/shaders.properties
+++ b/shaders/shaders.properties
@@ -19,7 +19,7 @@ screen.COLOR=colorMode dithering <empty> rgbSteps <empty> <empty> hueSteps satSt
 screen.PSX=vWarp tWarp
 
 #	fx
-screen.FX=worldCurvature
+screen.FX=dof worldCurvature
 
 #	-- CONDITIONALS --
 gbuffers_hand.enabled=tWarp