From 21f2d6768c242e3f41c0ac77805f05f14cff5eef Mon Sep 17 00:00:00 2001
From: MEEPofFaith <54301439+MEEPofFaith@users.noreply.github.com>
Date: Mon, 18 Nov 2024 20:40:39 -0800
Subject: [PATCH] Better scaling

---
 src/progressed/graphics/draw3d/Lines3D.java   |  4 +--
 .../graphics/draw3d/Perspective.java          | 25 +++++++++++--------
 2 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/progressed/graphics/draw3d/Lines3D.java b/src/progressed/graphics/draw3d/Lines3D.java
index ddcc0ab9..3bed6cc0 100644
--- a/src/progressed/graphics/draw3d/Lines3D.java
+++ b/src/progressed/graphics/draw3d/Lines3D.java
@@ -67,7 +67,7 @@ public static int linePointCount(float x1, float y1, float z1, float x2, float y
     }
 
     public static float[] linePoints(float x1, float y1, float z1, float x2, float y2, float z2, int pointCount){
-        if(z1 > z2){ //Always return from bottom to top
+        if(z1 > z2){ //Always order from bottom to top. Needed for viewport check.
             float tx = x1, ty = y1, tz = z1;
             x1 = x2;
             y1 = y2;
@@ -78,7 +78,7 @@ public static float[] linePoints(float x1, float y1, float z1, float x2, float y
         }
 
         float vz = Perspective.viewportZ();
-        if(z2 > vz){ //If line goes above viewport height, scale to viewport height.
+        if(z2 > vz){ //If line goes above viewport, scale to viewport z.
             float scl = vz / (z2 - z1);
             x2 = x1 + (x2 - x1) * scl;
             y2 = y1 + (y2 - y1) * scl;
diff --git a/src/progressed/graphics/draw3d/Perspective.java b/src/progressed/graphics/draw3d/Perspective.java
index bc523c92..c9ccedaf 100644
--- a/src/progressed/graphics/draw3d/Perspective.java
+++ b/src/progressed/graphics/draw3d/Perspective.java
@@ -12,6 +12,8 @@ public class Perspective{
     public static float viewportOffset = 8f;
     /** Field of View in degrees */
     public static float fov = settings.getInt("pm-fov", 60);
+    public static float fadeDst = 128f;
+    public static float maxScale = 8f;
 
     /** @return If the z coordinate is below the viewport height. */
     public static boolean canDraw(float z){
@@ -44,15 +46,18 @@ public static float scale(float x, float y, float z){
 
         x -= cx;
         y -= cy;
-        z = cz - z;
+        float zz = cz - z;
+
+        float px = x / zz * cz; //Position scaled to far plane.
+        float py = y / zz * cz;
 
-        float px = x / z * cz;
-        float py = y / z * cz;
+        float vx = x / zz * viewportOffset; //Position scaled to near plane.
+        float vy = y / zz * viewportOffset;
 
-        float c1 = Mathf.dst(x, y), c2 = Mathf.dst(px, py);
-        float d1 = Mathf.dst(z, c1), d2 = Mathf.dst(cz, c2);
+        float d1 = Math3D.dst(vx, vy, cz - viewportOffset, x, y, z);
+        float d2 = Math3D.dst(vx, vy, cz - viewportOffset, px, py, 0);
 
-        return d2 / d1;
+        return 1f + (1f - d1 / d2) * (maxScale - 1f);
     }
 
     /** Fade out based on distance to viewport. */
@@ -60,7 +65,7 @@ public static float alpha(float x, float y, float z){
         float cx = camera.position.x, cy = camera.position.y;
         float cz = cameraZ();
 
-        float d1 = Math3D.dst(x, y, z, cx, cy, cz); //Distance between camera point
+        float d1 = Math3D.dst(x, y, z, cx, cy, cz); //Distance between camera and far point
 
         x -= cx;
         y -= cy;
@@ -72,14 +77,14 @@ public static float alpha(float x, float y, float z){
         float d2 = Math3D.dst(vx, vy, z); //Distance between camera and viewport pos
 
         float dst = d1 - d2;
-        float fadeDst = (cz - viewportOffset) / 8f;
+        float fade = Math.min(fadeDst, cz - viewportOffset);
 
-        if(dst > fadeDst){
+        if(dst > fade){
             return 1f;
         }else if(!canDraw(z)){ //Behind viewport, should be 0
             return 0f;
         }else{
-            return Mathf.clamp(dst / fadeDst);
+            return Mathf.clamp(dst / fade);
         }
     }