Image Shader

Image Shader

Only use a shader to display an image on your screen~
Note: compiling the shader may take some time!

How to prepare a custom image~

First, use ffmpeg (or any tool) to resize your image to 160×160 pixels.

Using ffmpeg:
ffmpeg -i Input.png -vf scale=160:160 image.png

Then place the resized image in the same directory as the Python script below.
Run the script to produce an image_chunks folder, then copy the 16 .glsl files inside into shaders/data/image_chunks (you need to unpack the shader pack first).
Enter the game, enable the custom image option in the shader settings, and wait for the shader to finish compiling — Then it's ok~

from PIL import Image
import os

def generate_glsl_chunks(image_path, output_dir="image_chunks"):
    try:
        img = Image.open(image_path).convert('RGBA')
    except FileNotFoundError:
        print(f"Error: Image file not found at {image_path}")
        return

    width, height = img.size
    if width != 160 or height != 160:
        print(f"Error: Image must be 160x160 pixels, but it is {width}x{height}.")
        print(f"You can use:")
        print(f"ffmpeg -i image.png -vf scale=160:160 output.png")
        print(f"to adjust the image resolution.")
        return
        
    os.makedirs(output_dir, exist_ok=True)
    chunk_size = 40
    num_chunks_x = width // chunk_size
    num_chunks_y = height // chunk_size

    for chunk_y in range(num_chunks_y):
        for chunk_x in range(num_chunks_x):
            left = chunk_x * chunk_size
            upper = chunk_y * chunk_size
            right = left + chunk_size
            lower = upper + chunk_size
            sub_img = img.crop((left, upper, right, lower))
            pixel_data = list(sub_img.getdata())

            array_name = f"image_data_{chunk_y}_{chunk_x}"
            output_file_path = os.path.join(output_dir, f"{array_name}.glsl")

            glsl_array = f"vec4 {array_name}[{chunk_size * chunk_size}] = vec4[{chunk_size * chunk_size}](\n"
            
            for i, pixel in enumerate(pixel_data):
                r, g, b, a = pixel
                glsl_array += f"    vec4({r/255.0}, {g/255.0}, {b/255.0}, {a/255.0})"
                if i < len(pixel_data) - 1:
                    glsl_array += ","
                if (i + 1) % 4 == 0:
                    glsl_array += "\n"
            
            glsl_array += ");\n"

            with open(output_file_path, 'w') as f:
                f.write(glsl_array)
            
            print(f"Generated file: {output_file_path}")

# --- Config ---
image_file = "image.png"
output_directory = "image_chunks"

generate_glsl_chunks(image_file, output_directory)