From 34a0388f4535c39b2acd685e275c2bcc7b6fae84 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tr=C3=A8sAbhi?= <43380238+tresabhi@users.noreply.github.com>
Date: Sat, 30 Mar 2024 11:28:34 -0500
Subject: [PATCH] fix: more accurate HE

---
 .../[id]/components/Characteristics/index.tsx |  5 ++
 .../shaders/fragment.glsl                     | 51 +++++++++++--------
 .../shaders/vertex.glsl                       |  2 +
 3 files changed, 36 insertions(+), 22 deletions(-)

diff --git a/src/app/tools/tankopedia/[id]/components/Characteristics/index.tsx b/src/app/tools/tankopedia/[id]/components/Characteristics/index.tsx
index f0f77649c..e9a3b0d40 100644
--- a/src/app/tools/tankopedia/[id]/components/Characteristics/index.tsx
+++ b/src/app/tools/tankopedia/[id]/components/Characteristics/index.tsx
@@ -419,6 +419,11 @@ export function Characteristics() {
         <InfoWithDelta name="Module damage" unit="hp" decimals={0}>
           {shell.damage.module * damageCoefficient}
         </InfoWithDelta>
+        {isExplosive(shell.type) && (
+          <InfoWithDelta name="Splash radius" unit="m" decimals={0}>
+            {shell.explosionRadius!}
+          </InfoWithDelta>
+        )}
         <InfoWithDelta name="Shell velocity" unit="m/s" decimals={0}>
           {shell.speed * shellVelocityCoefficient}
         </InfoWithDelta>
diff --git a/src/components/Armor/components/CoreArmorSceneComponent/shaders/fragment.glsl b/src/components/Armor/components/CoreArmorSceneComponent/shaders/fragment.glsl
index 195bbf966..283184728 100644
--- a/src/components/Armor/components/CoreArmorSceneComponent/shaders/fragment.glsl
+++ b/src/components/Armor/components/CoreArmorSceneComponent/shaders/fragment.glsl
@@ -1,5 +1,6 @@
 varying vec3 vNormal;
 varying vec3 vViewPosition;
+varying mat4 vProjectionMatrix;
 
 uniform float thickness;
 uniform float penetration;
@@ -20,7 +21,7 @@ uniform highp sampler2D spacedArmorDepth;
 
 float depthToDistance(float depth) {
   vec4 clipPosition = vec4(gl_FragCoord.xy / resolution * 2.0 - 1.0, depth * 2.0 - 1.0, 1.0);
-  vec4 eyePosition = viewMatrix * clipPosition;
+  vec4 eyePosition = inverse(vProjectionMatrix) * clipPosition;
   return length(eyePosition.xyz / eyePosition.w);
 }
 
@@ -41,36 +42,42 @@ void main() {
     bool twoCalibersRule = caliber > thickness * 2.0 && thickness > 0.0;
     float finalNormalization = twoCalibersRule ? ((1.4 * normalization * caliber) / (2.0 * thickness)) : normalization;
     float finalThickness = thickness / cos(max(0.0, angle - finalNormalization));
-    float remainingPenetration = penetration;
 
-    // world space is in meters
+    // world space in meters
     vec4 spacedArmorDepthFragment = texture2D(spacedArmorDepth, screenCoordinates);
     float spacedArmorDistance = depthToDistance(spacedArmorDepthFragment.r);
     float coreArmorDistance = depthToDistance(gl_FragCoord.z);
     float distanceFromSpacedArmor = coreArmorDistance - spacedArmorDistance;
 
-    if (useSpacedArmor && isUnderSpacedArmor) {
+    if (canSplash && useSpacedArmor && isUnderSpacedArmor) {
       float spacedArmorThickness = spacedArmorBufferFragment.r * penetration;
-      remainingPenetration -= spacedArmorThickness;
+      float finalDamage = 0.5 * damage * (1.0 - distanceFromSpacedArmor / explosionRadius) - 1.1 * (thickness + spacedArmorThickness);
 
-      if (isExplosive && remainingPenetration > 0.0) {
-        // there is a 50% penetration loss per meter for HEAT shells
-        remainingPenetration -= 0.5 * remainingPenetration * distanceFromSpacedArmor;
-      }
-    }
-
-    remainingPenetration = max(0.0, remainingPenetration);
-    float delta = finalThickness - remainingPenetration;
-    float randomization = remainingPenetration * 0.05;
-    penetrationChance = clamp(1.0 - (delta + randomization) / (2.0 * randomization), 0.0, 1.0);
-
-    if (canSplash) {
-      // only allow splashing if the damage equation deals more than 0 damage
-      float nominalArmorThickness = finalThickness - remainingPenetration;
-      float finalDamage = 0.5 * damage * (1.0 - distanceFromSpacedArmor / explosionRadius) - 1.1 * nominalArmorThickness;
-      splashChance = finalDamage > 0.0 ? 1.0 : 0.0; // TODO: add randomization here?
+      penetrationChance = 0.0;
+      splashChance = finalDamage > 0.0 ? 1.0 : 0.0;
     } else {
-      splashChance = 0.0;
+      float remainingPenetration = penetration;
+
+      if (useSpacedArmor && isUnderSpacedArmor) {
+        float spacedArmorThickness = spacedArmorBufferFragment.r * penetration;
+        remainingPenetration -= spacedArmorThickness;
+
+        if (isExplosive && remainingPenetration > 0.0) {
+          remainingPenetration -= 0.5 * remainingPenetration * distanceFromSpacedArmor;
+        }
+      }
+
+      remainingPenetration = max(0.0, remainingPenetration);
+      float delta = finalThickness - remainingPenetration;
+      float randomization = remainingPenetration * 0.05;
+      penetrationChance = clamp(1.0 - (delta + randomization) / (2.0 * randomization), 0.0, 1.0);
+
+      if (canSplash) {
+        float splashDamage = 0.5 * damage - 1.1 * finalThickness;
+        splashChance = splashDamage > 0.0 ? 1.0 : 0.0;
+      } else {
+        splashChance = 0.0;
+      }
     }
   }
 
diff --git a/src/components/Armor/components/CoreArmorSceneComponent/shaders/vertex.glsl b/src/components/Armor/components/CoreArmorSceneComponent/shaders/vertex.glsl
index 82f94e255..0e4d1407f 100644
--- a/src/components/Armor/components/CoreArmorSceneComponent/shaders/vertex.glsl
+++ b/src/components/Armor/components/CoreArmorSceneComponent/shaders/vertex.glsl
@@ -1,10 +1,12 @@
 varying vec3 vNormal;
 varying vec3 vViewPosition;
+varying mat4 vProjectionMatrix;
 
 void main() {
   vec4 vViewPosition4 = modelViewMatrix * vec4(position, 1.0);
 
   vViewPosition = vViewPosition4.xyz;
+  vProjectionMatrix = projectionMatrix;
   vNormal = normalMatrix * normal;
 
   gl_Position = projectionMatrix * vViewPosition4;