tiny.filigree.render

1pub const Canvas = struct {2    pixels: []u8,3    width: usize,4    height: usize,5    stride: usize,67    pub fn init(pixels: []u8, width: usize, height: usize, stride: usize) !Canvas {8        if (width == 0 or height == 0) return error.InvalidCanvas;9        const row_bytes = try std.math.mul(usize, width, 4);10        if (stride < row_bytes) return error.InvalidCanvas;11        const required = try std.math.add(12            usize,13            try std.math.mul(usize, stride, height - 1),14            row_bytes,15        );16        if (pixels.len < required) return error.InvalidCanvas;17        return .{18            .pixels = pixels,19            .width = width,20            .height = height,21            .stride = stride,22        };23    }2425    fn blend(self: Canvas, x: i32, y: i32, color: Color, coverage: u8) void {26        if (coverage == 0 or color.a == 0) return;27        if (x < 0 or y < 0) return;28        const ux: usize = @intCast(x);29        const uy: usize = @intCast(y);30        if (ux >= self.width or uy >= self.height) return;31        const src_a: u32 = (@as(u32, coverage) * @as(u32, color.a) + 127) / 255;32        if (src_a == 0) return;33        const offset = uy * self.stride + ux * 4;34        const dst_a: u32 = self.pixels[offset + 3];35        const inv_src_a: u32 = 255 - src_a;36        const out_a: u32 = src_a + (dst_a * inv_src_a) / 255;37        if (out_a == 0) {38            self.pixels[offset] = 0;39            self.pixels[offset + 1] = 0;40            self.pixels[offset + 2] = 0;41            self.pixels[offset + 3] = 0;42            return;43        }44        self.pixels[offset] = blendChannel(color.r, self.pixels[offset], src_a, dst_a, inv_src_a, out_a);45        self.pixels[offset + 1] = blendChannel(color.g, self.pixels[offset + 1], src_a, dst_a, inv_src_a, out_a);46        self.pixels[offset + 2] = blendChannel(color.b, self.pixels[offset + 2], src_a, dst_a, inv_src_a, out_a);47        self.pixels[offset + 3] = @intCast(@min(out_a, 255));48    }49};

1pub const Color = struct {2    r: u8 = 255,3    g: u8 = 255,4    b: u8 = 255,5    a: u8 = 255,6};

1pub const DrawOptions = struct {2    color: Color = .{},3};

1pub const Metrics = struct {2    advance_x: i32,3    advance_y: i32,4};

1const canvas = @import("canvas.zig");2const text = @import("text.zig");34pub const Color = canvas.Color;5pub const Canvas = canvas.Canvas;6pub const DrawOptions = text.DrawOptions;7pub const Metrics = text.Metrics;89pub const drawFallbackUtf8 = text.drawFallbackUtf8;10pub const drawGlyphRun = text.drawGlyphRun;11pub const drawUtf8 = text.drawUtf8;12pub const measureFallbackUtf8 = text.measureFallbackUtf8;13pub const measureGlyphRun = text.measureGlyphRun;14pub const measureUtf8 = text.measureUtf8;

1pub const render = @import("render/root.zig");