Don't use BufferedImage (#800)

Author: gamma-delta

Common/src/main/java/at/petrak/hexcasting/client/render/PatternTextureManager.java

@@ -4,11 +4,12 @@
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.texture.DynamicTexture;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.util.FastColor;
+import net.minecraft.util.Mth;
 import net.minecraft.util.Tuple;
 import net.minecraft.world.phys.Vec2;
 
-import java.awt.*;
-import java.awt.image.BufferedImage;
+import java.awt.geom.Line2D;
 import java.util.List;
 import java.util.*;
 import java.util.concurrent.*;
@@ -86,46 +87,38 @@ private static Map<String, ResourceLocation> registerTextures(String patTextureK
     }
 
     private static NativeImage drawLines(List<Vec2> points, HexPatternPoints staticPoints, float unscaledLineWidth, int resPerUnit) {
-        BufferedImage img = new BufferedImage((int)(staticPoints.fullWidth*resPerUnit), (int)(staticPoints.fullHeight*resPerUnit), BufferedImage.TYPE_INT_ARGB);
-        Graphics2D g2d = img.createGraphics();
-        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
-
-        g2d.setColor(new Color(0xFF_FFFFFF)); // set it to white so we can reuse the texture with different colors
-        g2d.setStroke(new BasicStroke(unscaledLineWidth * resPerUnit, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
+        NativeImage nativeImage = new NativeImage((int)(staticPoints.fullWidth*resPerUnit), (int)(staticPoints.fullHeight*resPerUnit), true);
         for (int i = 0; i < points.size() - 1; i++) {
             Tuple<Integer, Integer> pointFrom = getTextureCoordinates(points.get(i), staticPoints, resPerUnit);
             Tuple<Integer, Integer> pointTo = getTextureCoordinates(points.get(i+1), staticPoints, resPerUnit);
-            g2d.drawLine(pointFrom.getA(), pointFrom.getB(), pointTo.getA(), pointTo.getB());
+           drawLine(nativeImage, pointFrom.getA(), pointFrom.getB(), pointTo.getA(), pointTo.getB(), unscaledLineWidth * resPerUnit);
         }
-        g2d.dispose();
-        NativeImage nativeImage = new NativeImage(img.getWidth(), img.getHeight(), true);
-        for (int y = 0; y < img.getHeight(); y++)
-            for (int x = 0; x < img.getWidth(); x++)
-                nativeImage.setPixelRGBA(x, y, img.getRGB(x, y));
         return nativeImage;
     }
 
+    private static void drawLine(NativeImage image, int x0, int y0, int x1, int y1, float width) {
+        var line = new Line2D.Float(x0, y0, x1, y1);
+        var bounds = line.getBounds();
+        double halfWidth = width / 2;
+        for (int x = (int) (bounds.x - width - 1); x < (int) (bounds.x + bounds.width + width + 1); x++) {
+            for (int y = (int) (bounds.y - width - 1); y < (int) (bounds.y + bounds.height + width + 1); y++) {
+                double dist = line.ptSegDist(x, y);
+                int alpha = (int) (Mth.clamp(halfWidth - dist + 0.5, 0, 1) * 255);
+                if (alpha > 0) {
+                    int oldAlpha = FastColor.ARGB32.alpha(image.getPixelRGBA(x, y));
+                    int newAlpha = Math.max(oldAlpha, alpha);
+                    image.setPixelRGBA(x, y, 0xFFFFFF | (newAlpha << 24));
+                }
+            }
+        }
+    }
+
     private static Tuple<Integer, Integer> getTextureCoordinates(Vec2 point, HexPatternPoints staticPoints, int resPerUnit) {
         int x = (int) ( point.x * resPerUnit);
         int y = (int) ( point.y * resPerUnit);
         return new Tuple<>(x, y);
     }
 
-    // keeping this around just in case we ever decide to put the dots in the textures instead of dynamic
-    private static void drawHexagon(Graphics2D g2d, int x, int y, int radius) {
-        int fracOfCircle = 6;
-        Polygon hexagon = new Polygon();
-
-        for (int i = 0; i < fracOfCircle; i++) {
-            double theta = (i / (double) fracOfCircle) * Math.PI * 2;
-            int hx = (int) (x + Math.cos(theta) * radius);
-            int hy = (int) (y + Math.sin(theta) * radius);
-            hexagon.addPoint(hx, hy);
-        }
-
-        g2d.fill(hexagon);
-    }
-
     public static void repaint() {
         repaintIndex++;
         patternTexturesToAdd.clear();