Oscar64pp

Javascript (NodeJS) preprocessor for Oscar64
(c) 2023 by Dusty Murray (also under the psuedonym "Cursor Keys" or "Cursor Keys Retro")

Oscar64 is a modern C/C++ compiler for Windows or Linux, which compiles code for the Commodore 64, which was a popular computer in the 1980s.

This program can be called instead of the Oscar64 compiler.
It is a wrapper. It allows for inline code and data generation during compile time.
It does this by allowing you to write javascript code in your c files, inbetween start and end markers.

Prerequisits:
You need to have Oscar64 installed, which can be found here: https://github.com/drmortalwombat/oscar64 You need to have Nodejs installed, as well as "pngjs"
To install pngjs, just type: "npm install pngjs" on the commandline.

Usage:

node oscar64.js <path_to_oscar64> <temporary_path> <options_to_oscar64> <files_to_oscar64>

• First param is path to oscar64 binary
• Second param is temporary path for generated files
• All other params with "-" will be used for calling the compiler
• All other params without "-" are files to be preprocessed
• All given files will be preprocessed, and preprocessed files will be passed to the compiler

See tests folder and buildtests script on how to compile. See tests folder and src/testgen.c on some examples of code generation embedded in a c file

Start and End tag:

/*!CGJS

starts a section of nodejs code, where you can do code generation
*Note: this has to be on the start of a line

CGJS!*/

end a section of nodejs code, where you can do code generation
*Note: this has to be on the end of a line

Code Generation:
To create/generated code, you can use the following keywords:

• .byte - create a small number (0-255)
• .word - split the number up into a low and hi byte, and output both
• .number - create any number, do not care about it's size
• .hbyte - create a hexadecimal byte value
• .string - creates a "string"
• .code - any C code

Utility functions:
These are extra functions to help you do code generation or data generation

• pic = loadPicture( filename ) ; load a picture (png file)

byte = pic.get8MonoPixels( x, y , rgbForGroundColor ) ; get byte of 8 mono colored pixels, starting at x,y
rgb = getRGBPixel( x, y ) ; get rgb object, representing the pixel
index = getPalettePixel( x, y, rgbArray) ; get index of pixel, according to where the rgbValue matches the input color palette

• res = mod(a,b) ; modulus

• res = round(a) ; rounding down or up

• console.log( string or object ) ; log result during compiling / preprocessing for investigation

Example:
Create an array of chars, with values that represent the cosinus function.

char cos[256] = {
/*!CGJS

const amplitude = 127;
const frequency = 2 * Math.PI / 256;
for (let i = 0; i < 256; i++) {
const cosValue = Math.cos(frequency * i) * amplitude;
.byte Math.round(cosValue + 127)
}

CGJS!*/
};