Crate gravita_renderer 

Minimal 2D rendering helpers shared across examples.

This crate intentionally stays lightweight: it provides simple drawing primitives on top of a raw RGBA frame buffer. Higher-level scene logic lives in the individual examples.

Design Philosophy

• CPU-based: All rendering happens on the CPU, no GPU required
• Frame buffer: Works with any &mut [u8] RGBA buffer
• Coordinate system: Y increases upward (world space), caller handles conversion

Available Primitives

• clear — Fill the entire frame with a solid color
• draw_circle — Draw a filled circle
• draw_line — Draw a 1-pixel wide line (Bresenham’s algorithm)
• draw_axes — Draw X/Y debug axes

Example

use gravita_renderer::{clear, draw_circle, draw_line};
use gravita_math::Vec2;

let mut frame = vec![0u8; 800 * 600 * 4];

// Clear to dark blue
clear(&mut frame, [0x20, 0x20, 0x40, 0xff]);

// Draw a white circle
draw_circle(&mut frame, Vec2::new(400.0, 300.0), 50.0, [0xff; 4], 800, 600);

Functions

clear

Clear the entire frame to a solid color (RGBA).

draw_axes

Draw simple X/Y axes crossing at origin, useful for debugging.

draw_circle

Draw a filled circle into the frame.

draw_line

Draw a 1‑pixel wide line between two points using Bresenham’s algorithm.