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use ab_glyph::{FontRef, PxScale};
use image::Rgb;
use imageproc::drawing::{draw_text_mut, text_size};
use crate::figure::utilities::linetype::LineType;
/// A structure representing a pixel-based drawing canvas.
pub struct PixelCanvas {
/// Width of the canvas in pixels.
pub width: u32,
/// Height of the canvas in pixels.
pub height: u32,
/// Background color of the canvas (RGB format).
pub background_color: [u8; 3],
/// Buffer storing pixel data as a linear array.
pub buffer: Vec<u8>,
/// Margin around the canvas (in pixels).
pub margin: u32,
}
impl PixelCanvas {
/// Creates a new `PixelCanvas` with the specified dimensions, background color, and margin.
///
/// # Parameters
/// - `width`: The width of the canvas in pixels.
/// - `height`: The height of the canvas in pixels.
/// - `background_color`: The RGB color of the canvas background.
/// - `margin`: Margin size in pixels.
///
/// # Returns
/// A new `PixelCanvas` instance.
pub fn new(width: u32, height: u32, background_color: [u8; 3], margin: u32) -> Self {
let buffer = (0..(width * height * 3) as usize)
.map(|i| background_color[i % 3])
.collect::<Vec<u8>>();
Self {
width,
height,
background_color,
buffer,
margin,
}
}
/// Clears the canvas by filling it with the background color.
pub fn clear(&mut self) {
for i in (0..self.buffer.len()).step_by(3) {
self.buffer[i] = self.background_color[0];
self.buffer[i + 1] = self.background_color[1];
self.buffer[i + 2] = self.background_color[2];
}
}
/// Draws a single pixel at the specified coordinates with the given color.
///
/// # Parameters
/// - `x`: The x-coordinate of the pixel.
/// - `y`: The y-coordinate of the pixel.
/// - `color`: The RGB color of the pixel.
pub fn draw_pixel(&mut self, x: u32, y: u32, color: [u8; 3]) {
let index = ((y * self.width + x) * 3) as usize;
if index + 2 < self.buffer.len() {
self.buffer[index] = color[0];
self.buffer[index + 1] = color[1];
self.buffer[index + 2] = color[2];
}
}
/// Blends a pixel with the specified color and alpha value.
///
/// # Parameters
/// - `x`: The x-coordinate of the pixel.
/// - `y`: The y-coordinate of the pixel.
/// - `color`: The RGB color to blend.
/// - `alpha`: The transparency value (0.0 to 1.0).
pub fn blend_pixel(&mut self, x: u32, y: u32, color: [u8; 3], alpha: f64) {
let index = ((y * self.width + x) * 3) as usize;
if index + 2 < self.buffer.len() {
let existing_color = [
self.buffer[index],
self.buffer[index + 1],
self.buffer[index + 2],
];
let blended_color = [
(color[0] as f64 * alpha + existing_color[0] as f64 * (1.0 - alpha)) as u8,
(color[1] as f64 * alpha + existing_color[1] as f64 * (1.0 - alpha)) as u8,
(color[2] as f64 * alpha + existing_color[2] as f64 * (1.0 - alpha)) as u8,
];
self.buffer[index] = blended_color[0];
self.buffer[index + 1] = blended_color[1];
self.buffer[index + 2] = blended_color[2];
}
}
/// Draws a horizontal line at the specified y-coordinate.
///
/// # Parameters
/// - `y`: The y-coordinate of the line.
/// - `color`: The RGB color of the line.
pub fn draw_horizontal_line(&mut self, y: u32, color: [u8; 3]) {
for x in self.margin..self.width - self.margin {
self.draw_pixel(x, y, color);
}
}
/// Draws a vertical line at the specified x-coordinate.
///
/// # Parameters
/// - `x`: The x-coordinate of the line.
/// - `color`: The RGB color of the line.
pub fn draw_vertical_line(&mut self, x: u32, color: [u8; 3]) {
for y in self.margin..self.height - self.margin {
self.draw_pixel(x, y, color);
}
}
/// Draws a grid on the canvas.
///
/// # Parameters
/// - `grid_size`: An array specifying the spacing of grid lines in the x and y directions.
/// - `color`: The RGB color of the grid lines.
pub fn draw_grid(&mut self, grid_size: &[usize; 2], color: [u8; 3]) {
for x in (self.margin..=self.width - self.margin).step_by(grid_size[0]) {
self.draw_vertical_line(x, color);
}
for y in (self.margin..=self.height - self.margin).step_by(grid_size[1]) {
self.draw_horizontal_line(y, color);
}
}
/// Draws text vertically at the specified position.
///
/// # Parameters
/// - `x`: The x-coordinate for the text.
/// - `y`: The y-coordinate for the text.
/// - `text`: The text content.
/// - `color`: The RGB color of the text.
/// - `font`: The font reference for rendering text.
/// - `scale`: The scaling factor for the font size.
pub fn draw_text_vertical(
&mut self,
x: u32,
y: u32,
text: &str,
color: [u8; 3],
font: &ab_glyph::FontRef,
scale: ab_glyph::PxScale,
) {
let mut current_y = y;
// Draw each character vertically
for ch in text.chars() {
let char_as_str = ch.to_string();
let (_char_width, char_height) = text_size(scale, font, &char_as_str);
// Draw the character
self.draw_text(x, current_y, &char_as_str, color, font, scale);
// Move down for the next character
current_y += char_height + 5; // Adjust spacing between characters
}
}
/// Draws text at the specified position.
///
/// # Parameters
/// - `x`: The x-coordinate for the text.
/// - `y`: The y-coordinate for the text.
/// - `text`: The text content.
/// - `color`: The RGB color of the text.
/// - `font`: The font reference for rendering text.
/// - `scale`: The scaling factor for the font size.
pub fn draw_text(
&mut self,
x: u32,
y: u32,
text: &str,
color: [u8; 3],
font: &FontRef,
scale: PxScale,
) {
let img: &mut [u8] = &mut self.buffer;
let mut buffer =
image::ImageBuffer::from_raw(self.width, self.height, img.to_vec()).unwrap();
draw_text_mut(
&mut buffer,
Rgb(color),
x as i32,
y as i32,
scale,
&font,
text,
);
self.buffer = buffer.into_raw();
}
/// Draws a line with the specified type (solid, dashed, or dotted).
///
/// # Parameters
/// - `x1`, `y1`: Coordinates of the start point.
/// - `x2`, `y2`: Coordinates of the end point.
/// - `color`: The RGB color of the line.
/// - `line_type`: The type of line to draw (`LineType`).
pub fn draw_line(
&mut self,
x1: i32,
y1: i32,
x2: i32,
y2: i32,
color: [u8; 3],
line_type: LineType,
) {
let dx = (x2 - x1).abs();
let dy = -(y2 - y1).abs();
let sx = if x1 < x2 { 1 } else { -1 };
let sy = if y1 < y2 { 1 } else { -1 };
let mut err = dx + dy;
let mut x = x1;
let mut y = y1;
match line_type {
LineType::Solid => {
// Draw a continuous line without any gaps
while x != x2 || y != y2 {
self.draw_pixel(x as u32, y as u32, color);
let e2 = 2 * err;
if e2 >= dy {
err += dy;
x += sx;
}
if e2 <= dx {
err += dx;
y += sy;
}
}
// Draw the final pixel
self.draw_pixel(x2 as u32, y2 as u32, color);
}
LineType::Dashed(dash_length) => {
let mut is_drawing = true;
let mut segment_length = 0;
while x != x2 || y != y2 {
if is_drawing {
self.draw_pixel(x as u32, y as u32, color);
}
segment_length += 1;
if segment_length == dash_length {
is_drawing = !is_drawing; // Toggle drawing
segment_length = 0; // Reset segment length
}
let e2 = 2 * err;
if e2 >= dy {
err += dy;
x += sx;
}
if e2 <= dx {
err += dx;
y += sy;
}
}
// Ensure the final pixel is drawn in drawing mode
if is_drawing {
self.draw_pixel(x2 as u32, y2 as u32, color);
}
}
LineType::Dotted(dot_spacing) => {
let mut is_drawing = true;
let mut segment_length = 0;
// For dotted lines: always use small dots (2-3 pixels) with variable spacing
let dot_length = 3;
while x != x2 || y != y2 {
if is_drawing {
self.draw_pixel(x as u32, y as u32, color);
}
segment_length += 1;
let threshold = if is_drawing { dot_length } else { dot_spacing };
if segment_length == threshold {
is_drawing = !is_drawing; // Toggle drawing
segment_length = 0; // Reset segment length
}
let e2 = 2 * err;
if e2 >= dy {
err += dy;
x += sx;
}
if e2 <= dx {
err += dx;
y += sy;
}
}
// Ensure the final pixel is drawn in drawing mode
if is_drawing {
self.draw_pixel(x2 as u32, y2 as u32, color);
}
}
}
}
/// Saves the current canvas as an image file.
///
/// # Parameters
/// - `file_path`: The path to save the image file.
///
/// # Panics
/// Panics if the image cannot be saved.
pub fn save_as_image(&self, file_path: &str) {
use image::{ImageBuffer, RgbImage};
let img: RgbImage = ImageBuffer::from_raw(self.width, self.height, self.buffer.clone())
.expect("Failed to create image buffer");
img.save(file_path).expect("Failed to save image");
}
}