Texture Manipulation

Texture Manipulation

Open a texture, take its colors apart, and build a new one out of them, in code, at load time.

This is what feeds Runtime Resource Packs. The usual job is "make a version of this texture in every wood color that's installed": extract the palette of the target wood, then repaint your template with it.

The pieces:

• TextureImage, a NativeImage plus its mcmeta, so animated textures keep working. Read and write pixels per frame, copy, crop, mask, rotate, resize, grayscale, overlay, or turn a still into an animation.
• Palette, the colors of an image sorted by luminance, with everything you need to reshape it: add a brighter color, add one in between, merge the two closest, match a target size or luminance step. Colors are the ones from Colors, so you can work in HSL or LAB and come back.
• Respriter, which keeps the shape of one texture and swaps in the colors of a palette.
• TextureCollager, which copies rectangles between images with flips, rotations and scaling.
• RPUtils, which digs a block's actual texture path out of its models, since you rarely know it up front.

Getting Started

try (TextureImage stone = TextureImage.open(manager, ResourceLocation.parse("block/stone"));
     TextureImage deepslate = TextureImage.open(manager, ResourceLocation.parse("block/deepslate"))) {

    // keeps the shape of stone, takes colors from whatever you feed it
    Respriter respriter = Respriter.of(stone);

    Palette palette = Palette.fromImage(deepslate);
    palette.remove(palette.getDarkest());
    if (palette.getLuminanceSpan() < 0.2) palette.increaseUp();

    TextureImage recolored = respriter.recolor(palette);
    recolored.setFramePixel(0, 1, 1, 0xff0000ff);
    return recolored;   // caller closes it
}

Finding a texture you don't know the path of:

ResourceLocation tex = RPUtils.findFirstBlockTextureLocation(manager, Blocks.DIAMOND_BLOCK);

Collaging, built once and applied many times:

TextureCollager collager = TextureCollager.builder(16, 16, 16, 16)
        .copyFrom(6, 6, 4, 4).to(12, 0).flippedX()
        .copyFrom(0, 0, 4, 5).to(2, 3).rotated(Rotation.CLOCKWISE_90)
        .build();

collager.apply(emerald, myImage);

Warning

TextureImage holds native memory. Always try with resources, or hand it to ResourceSink.addAndCloseTexture(...) which closes it for you. Leaks here are real leaks.

Examples: TextureUtilsExample, PaletteExample

Also here

SpriteUtils can guess a sign or wooden item palette from a planks texture (extrapolateSignBlockPalette, extrapolateWoodItemPalette), which is how wood variants of complex textures get generated. It also has reduceColors and mergeSimilarColors.

KMeans clusters colors when plain palette extraction is too coarse.