From df900a2e463cdc979bc0d00436d7913eaff764d6 Mon Sep 17 00:00:00 2001
From: fly <merspieler@airmail.cc>
Date: Thu, 12 Nov 2020 04:16:58 +1100
Subject: [PATCH] High fov Distortion correction

Signed-off-by: fly <merspieler@airmail.cc>
---
 Compositor/Effects/projection-2d.eff      |  44 +++++++
 Compositor/Shaders/ALS/projection-2d.frag |  29 +++++
 Compositor/als-projection-2d.xml          | 142 ++++++++++++++++++++++
 3 files changed, 215 insertions(+)
 create mode 100644 Compositor/Effects/projection-2d.eff
 create mode 100644 Compositor/Shaders/ALS/projection-2d.frag
 create mode 100644 Compositor/als-projection-2d.xml

diff --git a/Compositor/Effects/projection-2d.eff b/Compositor/Effects/projection-2d.eff
new file mode 100644
index 000000000..c65a85874
--- /dev/null
+++ b/Compositor/Effects/projection-2d.eff
@@ -0,0 +1,44 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<PropertyList>
+	<name>Effects/Compositor/projection-2d</name>
+	<parameters>
+		<hfov><use>/sim/current-view/field-of-view</use></hfov>
+		<display_xsize>
+			<use>/sim/startup/xsize</use>
+		</display_xsize>
+		<display_ysize>
+			<use>/sim/startup/ysize</use>
+		</display_ysize>
+	</parameters>
+	<technique n="1">
+		<pass>
+			<program>
+				<fragment-shader>Compositor/Shaders/ALS/projection-2d.frag</fragment-shader>
+			</program>
+			<texture-unit>
+				<unit>2</unit>
+				<type>2d</type>
+			</texture-unit>
+			<uniform>
+				<name>display_x</name>
+				<type>int</type>
+				<value><use>display_xsize</use></value>
+			</uniform>
+			<uniform>
+				<name>display_y</name>
+				<type>int</type>
+				<value><use>display_ysize</use></value>
+			</uniform>
+			<uniform>
+				<name>hfov</name>
+				<type>float</type>
+				<value><use>hfov</use></value>
+			</uniform>
+			<uniform>
+				<name>iChannel0</name>
+				<type>sampler-2d</type>
+				<value>2</value>
+			</uniform>
+		</pass>
+	</technique>
+</PropertyList>
diff --git a/Compositor/Shaders/ALS/projection-2d.frag b/Compositor/Shaders/ALS/projection-2d.frag
new file mode 100644
index 000000000..e86cf72b1
--- /dev/null
+++ b/Compositor/Shaders/ALS/projection-2d.frag
@@ -0,0 +1,29 @@
+// uniforms
+uniform float hfov;
+uniform vec2 fg_ViewportSize;
+uniform sampler2D iChannel0;
+uniform int display_x;
+uniform int display_y;
+
+void main(void)
+{
+	// Defines
+	float pi = 3.1415926535897932384626433832795;
+	// Guess vfov based on screen dimensions
+	float vfov = hfov * (fg_ViewportSize.y / fg_ViewportSize.x);
+
+	// Normalize	
+	vec2 uv = gl_FragCoord.xy / fg_ViewportSize.xy;
+	// Indicates the position we want on the input
+	vec2 ray = vec2(0.0, 0.0);
+
+	// Correction for the distortion in the original image
+	//ray.y = 0.5 * tan((vfov/180.0) * (uv.y - 0.5) * pi) / tan(0.5 * (vfov/180.0) * pi) + 0.5;
+	ray.y = uv.y;
+	ray.x = 0.5 * tan((hfov/180.0) * (uv.x - 0.5) * pi) / tan(0.5 * (hfov/180.0) * pi) + 0.5;
+
+	// Lookup on the input texture
+	vec4 ret = texture2D( iChannel0, ray.xy );
+	ret.a = 1.0;
+	gl_FragColor = ret;
+}
diff --git a/Compositor/als-projection-2d.xml b/Compositor/als-projection-2d.xml
new file mode 100644
index 000000000..8dda3e5ed
--- /dev/null
+++ b/Compositor/als-projection-2d.xml
@@ -0,0 +1,142 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<PropertyList>
+  <name>ALS</name>
+
+  <buffer>
+    <name>color</name>
+    <type>2d</type>
+    <width>screen</width>
+    <height>screen</height>
+    <format>rgba8</format>
+  </buffer>
+  <buffer>
+    <name>depth</name>
+    <type>2d</type>
+    <width>screen</width>
+    <height>screen</height>
+    <format>depth32f</format>
+  </buffer>
+  <!--buffer>
+    <name>color</name>
+    <type>cubemap</type>
+    <width>2048</width>
+    <height>2048</height>
+    <format>rgba8</format>
+  </buffer>
+  <buffer>
+    <name>depth</name>
+    <type>cubemap</type>
+    <width>2048</width>
+    <height>2048</height>
+    <format>depth32f</format>
+  </buffer-->
+  <buffer>
+    <name>sun-shadowmap-atlas</name>
+    <type>2d</type>
+    <width><property>/sim/rendering/als/shadows/sun-atlas-size</property></width>
+    <height><property>/sim/rendering/als/shadows/sun-atlas-size</property></height>
+    <format>depth32f</format>
+    <wrap-s>clamp-to-border</wrap-s>
+    <wrap-t>clamp-to-border</wrap-t>
+    <wrap-r>clamp-to-border</wrap-r>
+    <min-filter>linear</min-filter>
+    <mag-filter>linear</mag-filter>
+    <border-color type="vec4d">1.0 1.0 1.0 1.0</border-color>
+    <shadow-comparison>true</shadow-comparison>
+  </buffer>
+
+
+  <!-- Shadow mapping pre-passes -->
+  <pass include="ALS/csm.xml">
+    <name>csm0</name>
+    <near-m>0.1</near-m>
+    <far-m>3.0</far-m>
+    <viewport>
+      <x>0.0</x>
+      <y>0.0</y>
+      <width>0.5</width>
+      <height>0.5</height>
+    </viewport>
+  </pass>
+  <pass include="ALS/csm.xml">
+    <name>csm1</name>
+    <near-m>3.0</near-m>
+    <far-m>50.0</far-m>
+    <viewport>
+      <x>0.5</x>
+      <y>0.0</y>
+      <width>0.5</width>
+      <height>0.5</height>
+    </viewport>
+  </pass>
+  <pass include="ALS/csm.xml">
+    <name>csm2</name>
+    <near-m>50.0</near-m>
+    <far-m>150.0</far-m>
+    <viewport>
+      <x>0.0</x>
+      <y>0.5</y>
+      <width>0.5</width>
+      <height>0.5</height>
+    </viewport>
+  </pass>
+  <pass include="ALS/csm.xml">
+    <name>csm3</name>
+    <near-m>150.0</near-m>
+    <far-m>1500.0</far-m>
+    <viewport>
+      <x>0.5</x>
+      <y>0.5</y>
+      <width>0.5</width>
+      <height>0.5</height>
+    </viewport>
+  </pass>
+
+  <pass>
+    <name>forward</name>
+    <type>scene</type>
+    <effect-scheme>als-lighting</effect-scheme>
+
+    <clustered-shading>
+      <tile-size>128</tile-size>
+      <num-threads>1</num-threads>
+      <depth-slices>1</depth-slices>
+    </clustered-shading>
+
+    <use-shadow-pass>csm0</use-shadow-pass>
+    <use-shadow-pass>csm1</use-shadow-pass>
+    <use-shadow-pass>csm2</use-shadow-pass>
+    <use-shadow-pass>csm3</use-shadow-pass>
+
+	 <!--cubemap-face>5</cubemap-face-->
+
+    <binding>
+      <buffer>sun-shadowmap-atlas</buffer>
+      <unit>10</unit>
+    </binding>
+
+    <attachment>
+      <buffer>color</buffer>
+      <component>color0</component>
+      <multisample-samples>4</multisample-samples>
+      <multisample-color-samples>4</multisample-color-samples>
+    </attachment>
+	<attachment>
+      <buffer>depth</buffer>
+      <component>depth</component>
+      <multisample-samples>4</multisample-samples>
+      <multisample-color-samples>4</multisample-color-samples>
+    </attachment>
+  </pass>
+
+  <pass>
+    <name>display</name>
+    <type>quad</type>
+    <binding>
+      <buffer>color</buffer>
+      <unit>2</unit>
+    </binding>
+    <effect>Compositor/Effects/projection-2d</effect>
+  </pass>
+</PropertyList>