63 lines
2.1 KiB
Rust
63 lines
2.1 KiB
Rust
use embedded_graphics::{geometry::Size, pixelcolor::Rgb565, primitives::Rectangle, prelude::Point};
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use embedded_graphics_core::draw_target::DrawTarget;
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use crate::display::palette::Rgb;
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pub fn render_sprite_onto_ili9341<D>(ili9341: &mut D, sprite: &[u8], palette: &[Rgb; 16])
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where
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D: DrawTarget<Color = Rgb565>,
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{
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let pixel_count = sprite.len() * 2;
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if pixel_count == 0 {
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return;
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}
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// OPTIMIZATION 1: Pre-compute the 16-color palette to Rgb565 once.
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let mut palette565 = [Rgb565::new(0, 0, 0); 16];
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for (i, Rgb(r, g, b)) in palette.iter().enumerate() {
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palette565[i] = Rgb565::new(*r >> 3, *g >> 2, *b >> 3);
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}
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let mut src_width = 1usize;
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while src_width * src_width < pixel_count {
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src_width += 1;
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}
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let target_width = 240usize;
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let scale = core::cmp::max(1, target_width / src_width);
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for y in 0..src_width {
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for x in 0..src_width {
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let pixel_index = y * src_width + x;
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if pixel_index >= pixel_count {
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break;
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}
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// Bitwise operations are slightly faster than division/modulo
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let byte_index = pixel_index >> 1;
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let pixel_byte = sprite[byte_index];
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let color_index = if pixel_index.is_multiple_of(2) {
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(pixel_byte >> 4) & 0x0F
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} else {
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pixel_byte & 0x0F
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};
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let color = palette565[color_index as usize];
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let start_x = (x * scale) as i32;
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let start_y = (y * scale) as i32;
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let end_x = core::cmp::min(start_x + scale as i32, target_width as i32);
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let end_y = core::cmp::min(start_y + scale as i32, target_width as i32);
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let width = u32::try_from(end_x - start_x).unwrap();
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let height = u32::try_from(end_y - start_y).unwrap();
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let area = Rectangle::new(
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Point::new(start_x.try_into().unwrap(), start_y.try_into().unwrap()),
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Size::new(width, height),
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);
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let _ = ili9341.fill_solid(&area, color);
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}
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}
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}
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