sprite tool exports "formatted" TGA

meaning if alpha is zero, RGB is also zero
2026-03-08 12:51:51 +09:00 · 2019-01-07 17:11:43 +09:00
parent 790d16b85d
commit 9133f05b5e
3 changed files with 124 additions and 7 deletions
--- a/src/com/badlogic/gdx/graphics/PixmapIO2.java
+++ b/src/com/badlogic/gdx/graphics/PixmapIO2.java
@@ -0,0 +1,89 @@
+package com.badlogic.gdx.graphics;
+
+import com.badlogic.gdx.files.FileHandle;
+import com.badlogic.gdx.utils.StreamUtils;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * Created by minjaesong on 2019-01-07.
+ */
+public class PixmapIO2 {
+
+    public static void writeTGA(FileHandle file, Pixmap pixmap) throws IOException {
+        OutputStream output = file.write(false);
+
+        try {
+            _writeTGA(output, pixmap);
+        } finally {
+            StreamUtils.closeQuietly(output);
+        }
+    }
+
+    private static void _writeTGA(OutputStream out, Pixmap pixmap) throws IOException {
+        byte[] width = toShortLittle(pixmap.getWidth());
+        byte[] height = toShortLittle(pixmap.getHeight());
+        byte[] zero = toShortLittle(0);
+
+        byte[] zeroalpha = new byte[]{0,0,0,0};
+
+        out.write(0); // ID field: empty
+        out.write(0); // no colour map, but should be ignored anyway as it being unmapped RGB
+        out.write(2); // 2 means unmapped RGB
+        out.write(new byte[]{0,0,0,0,0}); // color map spec: empty
+        out.write(zero); // x origin: 0
+        out.write(zero); // y origin: 0
+        out.write(width); // width
+        out.write(height); // height
+        out.write(32); // image pixel size: we're writing 32-bit image (8bpp BGRA)
+        out.write(8); // image descriptor: dunno, Photoshop writes 8 in there
+
+        // write actual image data
+        // since we're following Photoshop's conventional header, we also follows Photoshop's
+        // TGA saving scheme, that is:
+        //     1. BGRA order
+        //     2. Y-Flipped but not X-Flipped
+
+        for (int y = pixmap.getHeight() - 1; y >= 0; y--) {
+            for (int x = 0; x < pixmap.getWidth(); x++) {
+                int color = pixmap.getPixel(x, y);
+
+                // if alpha == 0, write special value instead
+                if ((color & 0xFF) == 0) {
+                    out.write(zeroalpha);
+                }
+                else {
+                    out.write(RGBAtoBGRA(color));
+                }
+            }
+        }
+
+
+        // write footer
+        // 00 00 00 00 00 00 00 00 TRUEVISION-XFILE 2E 00
+        out.write(new byte[]{0,0,0,0,0,0,0,0});
+        out.write("TerrarumHappyTGA".getBytes());
+        out.write(new byte[]{0x2E,0});
+
+
+        out.flush();
+        out.close();
+    }
+
+    private static byte[] toShortLittle(int i) {
+        return new byte[]{
+                (byte) (i & 0xFF),
+                (byte) ((i >>> 8) & 0xFF)
+        };
+    }
+
+    private static byte[] RGBAtoBGRA(int rgba) {
+        return new byte[]{
+                (byte) ((rgba >>> 8) & 0xFF),
+                (byte) ((rgba >>> 16) & 0xFF),
+                (byte) ((rgba >>> 24) & 0xFF),
+                (byte) (rgba & 0xFF)
+        };
+    }
+}