Correct line point pos

Author: MEEPofFaith

src/progressed/graphics/draw3d/Lines3D.java

@@ -79,7 +79,7 @@ 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, scale to viewport z.
-            float scl = vz / (z2 - z1);
+            float scl = (vz - z1) / (z2 - z1);
             x2 = x1 + (x2 - x1) * scl;
             y2 = y1 + (y2 - y1) * scl;
             z2 = vz;

src/progressed/graphics/draw3d/Perspective.java

@@ -12,15 +12,15 @@
 public class Perspective{
     private static final Vec2 offsetPos = new Vec2();
     /** Viewport offset from the camera height in world units. */
-    public static float viewportOffset = 8f;
+    public static float viewportOffset = 16f;
     /** Field of View in degrees */
     public static float fov = -1f;
     public static float fadeDst = 1024f;
     public static float maxScale = 8f;
 
     private static float lastScale;
     private static float cameraZ;
-    private static Vec2 viewportSize = new Vec2();
+    private static final Vec2 viewportSize = new Vec2();
 
     static{
         if(!headless){
@@ -38,7 +38,7 @@ public class Perspective{
 
     /** @return If the z coordinate is below the viewport height. */
     public static boolean canDraw(float z){
-        return z < cameraZ - viewportOffset;
+        return z < viewportZ();
     }
 
     /** @return Perspective projected coordinates to draw at. */
@@ -98,13 +98,16 @@ public static float alpha(float x, float y, float z){
 
         if(dst > fade){
             return 1f;
-        }else if(!canDraw(z)){ //Behind viewport, should be 0
+        }else if(z > vz){ //Behind viewport, should be 0
             return 0f;
         }else{
             return Mathf.clamp(dst / fade);
         }
     }
 
+    /**
+     * @return camera z coordinate
+     */
     public static float cameraZ(){
         return cameraZ;
     }

src/progressed/world/blocks/defence/turret/testing/SkyLaserTestTurret.java

@@ -1,6 +1,7 @@
 package progressed.world.blocks.defence.turret.testing;
 
 import progressed.entities.bullet.pseudo3d.*;
+import progressed.graphics.draw3d.*;
 
 import static mindustry.Vars.*;
 
@@ -26,7 +27,7 @@ public void draw(){
             super.draw();
 
             SkyBeamBulletType type = (SkyBeamBulletType)shootType;
-            //Draw3D.drawLineDebug(x, y, type.z, targetPos.x, targetPos.y, 0);
+            Draw3D.drawLineDebug(x, y, type.z, targetPos.x, targetPos.y, 0);
             //Draw3D.drawDiskDebug(targetPos.x, targetPos.y, x, y, type.z, type.radius);
         }
     }