png2asm

png2asm is a lightweight Go tool designed to convert 256-color paletted PNG images into assembly-compatible .inc files. This is particularly useful for retro game development, embedded systems, or any scenario where you need to integrate graphical assets directly into assembly code.

The tool extracts the color index for each pixel from the input PNG and outputs it as a byte array, ready to be included in your assembly projects.

Features

• Converts 256-color paletted PNG images.
• Generates an assembly .inc file containing pixel color indices.
• Supports custom input PNG file names.
• Includes comments in the generated .inc file for clarity.

Requirements

• Go Language: You need to have Go installed on your system (if you want to build from source).
• 256-color Paletted PNG Image: The input image must be a PNG with a 256-color palette (indexed color mode). The tool will terminate with an error if a non-paletted image is provided.

Usage

1. Build the Executable: Navigate to the project directory and build the executable:

   go build -o png2asm main.go

2. Prepare Your Image: Place your 256-color paletted PNG image in the same directory as the png2asm executable, or specify its path.

3. Run the Tool:

   • Using the default input file (sprite.png): If your input image is named sprite.png:

     ./png2asm

   • Specifying a custom input file: Use the -src flag to provide the path to your PNG image:

     ./png2asm -src path/to/your_image.png

   The tool will generate a file named sprite.inc in the current directory.

Example Output (sprite.inc)

Given an input sprite.png (for example, an 8x8 sprite), the generated sprite.inc file might look something like this:

; Automatically generated sprite
my_sprite LABEL BYTE
    DB 0,1,2,3,4,5,6,7
    DB 8,9,10,11,12,13,14,15
    DB 16,17,18,19,20,21,22,23
    DB 24,25,26,27,28,29,30,31
    DB 32,33,34,35,36,37,38,39
    DB 40,41,42,43,44,45,46,47
    DB 48,49,50,51,52,53,54,55
    DB 56,57,58,59,60,61,62,63

GIMP Palette

The gimp directory contains two files that can be used with GIMP to create images with the correct VGA palette.

• VGA.gpl: This is the palette file. You can install it in GIMP by copying it to ~/.config/GIMP/2.10/palettes/.
• vga.icc: This is the color profile. You can install it in GIMP by copying it to ~/.config/GIMP/2.10/profiles/.

Using these files will help ensure that your images use the standard VGA 256-color palette, which is required for this tool.