font: start converting Box font to our abstract canvas interface

This commit is contained in:
Mitchell Hashimoto
2022-12-13 16:16:56 -08:00
parent c34d911488
commit b21e18a9e6
6 changed files with 1165 additions and 1044 deletions

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@ -73,7 +73,7 @@ pub const Fixed = enum(i32) {
pub fn init(v: anytype) Fixed {
return switch (@TypeOf(v)) {
comptime_int, u32 => @intToEnum(Fixed, v << 16),
comptime_int, i32, u32 => @intToEnum(Fixed, v << 16),
f64 => @intToEnum(Fixed, @floatToInt(i32, v * 65536)),
else => {
@compileLog(@TypeOf(v));

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@ -1,5 +1,5 @@
const std = @import("std");
pub const Canvas = @import("sprite/Canvas.zig");
pub usingnamespace @import("sprite/canvas.zig");
pub const Face = @import("sprite/Face.zig");
/// Sprites are represented as special codepoints outside of the Unicode

File diff suppressed because it is too large Load Diff

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@ -1,131 +0,0 @@
//! This exposes primitives to draw 2D graphics and export the graphic to
//! a font atlas.
const Canvas = @This();
const std = @import("std");
const assert = std.debug.assert;
const Allocator = std.mem.Allocator;
const pixman = @import("pixman");
const font = @import("../main.zig");
/// The underlying image.
image: *pixman.Image,
/// The raw data buffer.
data: []u32,
pub const Rect = struct {
x: u32,
y: u32,
width: u32,
height: u32,
};
/// We only use alpha-channel so a pixel can only be "on" or "off".
pub const Color = enum {
on,
off,
fn pixmanColor(self: Color) pixman.Color {
return switch (self) {
.on => .{ .red = 0xFFFF, .green = 0xFFFF, .blue = 0xFFFF, .alpha = 0xFFFF },
.off => .{ .red = 0, .green = 0, .blue = 0, .alpha = 0 },
};
}
};
pub fn init(alloc: Allocator, width: u32, height: u32) !Canvas {
// Determine the config for our image buffer. The images we draw
// for boxes are always 8bpp
const format: pixman.FormatCode = .a8;
const stride = format.strideForWidth(width);
const len = @intCast(usize, stride * @intCast(c_int, height));
// Allocate our buffer. pixman uses []u32 so we divide our length
// by 4 since u32 / u8 = 4.
var data = try alloc.alloc(u32, len / 4);
errdefer alloc.free(data);
std.mem.set(u32, data, 0);
// Create the image we'll draw to
const img = try pixman.Image.createBitsNoClear(
format,
@intCast(c_int, width),
@intCast(c_int, height),
data.ptr,
stride,
);
errdefer _ = img.unref();
return Canvas{
.image = img,
.data = data,
};
}
pub fn deinit(self: *Canvas, alloc: Allocator) void {
alloc.free(self.data);
_ = self.image.unref();
self.* = undefined;
}
/// Write the data in this drawing to the atlas.
pub fn writeAtlas(self: *Canvas, alloc: Allocator, atlas: *font.Atlas) !font.Atlas.Region {
assert(atlas.format == .greyscale);
const width = @intCast(u32, self.image.getWidth());
const height = @intCast(u32, self.image.getHeight());
const region = try atlas.reserve(alloc, width, height);
if (region.width > 0 and region.height > 0) {
const depth = atlas.format.depth();
// Convert our []u32 to []u8 since we use 8bpp formats
const stride = self.image.getStride();
const data = @alignCast(
@alignOf(u8),
@ptrCast([*]u8, self.data.ptr)[0 .. self.data.len * 4],
);
// We can avoid a buffer copy if our atlas width and bitmap
// width match and the bitmap pitch is just the width (meaning
// the data is tightly packed).
const needs_copy = !(width * depth == stride);
// If we need to copy the data, we copy it into a temporary buffer.
const buffer = if (needs_copy) buffer: {
var temp = try alloc.alloc(u8, width * height * depth);
var dst_ptr = temp;
var src_ptr = data.ptr;
var i: usize = 0;
while (i < height) : (i += 1) {
std.mem.copy(u8, dst_ptr, src_ptr[0 .. width * depth]);
dst_ptr = dst_ptr[width * depth ..];
src_ptr += @intCast(usize, stride);
}
break :buffer temp;
} else data[0..(width * height * depth)];
defer if (buffer.ptr != data.ptr) alloc.free(buffer);
// Write the glyph information into the atlas
assert(region.width == width);
assert(region.height == height);
atlas.set(region, buffer);
}
return region;
}
/// Draw and fill a rectangle. This is the main primitive for drawing
/// lines as well (which are just generally skinny rectangles...)
pub fn rect(self: *Canvas, v: Rect, color: Color) void {
const boxes = &[_]pixman.Box32{
.{
.x1 = @intCast(i32, v.x),
.y1 = @intCast(i32, v.y),
.x2 = @intCast(i32, v.x + v.width),
.y2 = @intCast(i32, v.y + v.height),
},
};
self.image.fillBoxes(.src, color.pixmanColor(), boxes) catch {};
}

288
src/font/sprite/canvas.zig Normal file
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@ -0,0 +1,288 @@
//! This exposes primitives to draw 2D graphics and export the graphic to
//! a font atlas.
const std = @import("std");
const assert = std.debug.assert;
const Allocator = std.mem.Allocator;
const pixman = @import("pixman");
const font = @import("../main.zig");
pub const Point = struct {
x: i32,
y: i32,
};
pub const Line = struct {
p1: Point,
p2: Point,
};
pub const Box = struct {
x1: i32,
y1: i32,
x2: i32,
y2: i32,
pub fn rect(self: Box) Rect {
const tl_x = @min(self.x1, self.x2);
const tl_y = @min(self.y1, self.y2);
const br_x = @max(self.x1, self.x2);
const br_y = @max(self.y1, self.y2);
return .{
.x = tl_x,
.y = tl_y,
.width = @intCast(u32, br_x - tl_x),
.height = @intCast(u32, br_y - tl_y),
};
}
};
pub const Rect = struct {
x: i32,
y: i32,
width: u32,
height: u32,
};
pub const Triangle = struct {
p1: Point,
p2: Point,
p3: Point,
};
pub const Trapezoid = struct {
top: i32,
bottom: i32,
left: Line,
right: Line,
};
/// We only use alpha-channel so a pixel can only be "on" or "off".
pub const Color = enum(u8) {
on = 255,
off = 0,
_,
fn pixmanColor(self: Color) pixman.Color {
// pixman uses u16 for color while our color value is u8 so we
// scale it up proportionally.
const max = @intToFloat(f32, std.math.maxInt(u8));
const max_u16 = @intToFloat(f32, std.math.maxInt(u16));
const unscaled = @intToFloat(f32, @enumToInt(self));
const scaled = @floatToInt(u16, (unscaled * max_u16) / max);
return .{ .red = 0, .green = 0, .blue = 0, .alpha = scaled };
}
};
/// Composition operations that are supported.
pub const CompositionOp = enum {
// Note: more can be added here as needed.
destination_out,
fn pixmanOp(self: CompositionOp) pixman.Op {
return switch (self) {
.destination_out => .out,
};
}
};
pub const Canvas = switch (font.options.backend) {
.web_canvas => WebCanvasImpl,
else => PixmanImpl,
};
const WebCanvasImpl = struct {};
const PixmanImpl = struct {
/// The underlying image.
image: *pixman.Image,
/// The raw data buffer.
data: []u32,
pub fn init(alloc: Allocator, width: u32, height: u32) !Canvas {
// Determine the config for our image buffer. The images we draw
// for boxes are always 8bpp
const format: pixman.FormatCode = .a8;
const stride = format.strideForWidth(width);
const len = @intCast(usize, stride * @intCast(c_int, height));
// Allocate our buffer. pixman uses []u32 so we divide our length
// by 4 since u32 / u8 = 4.
var data = try alloc.alloc(u32, len / 4);
errdefer alloc.free(data);
std.mem.set(u32, data, 0);
// Create the image we'll draw to
const img = try pixman.Image.createBitsNoClear(
format,
@intCast(c_int, width),
@intCast(c_int, height),
data.ptr,
stride,
);
errdefer _ = img.unref();
return Canvas{
.image = img,
.data = data,
};
}
pub fn deinit(self: *Canvas, alloc: Allocator) void {
alloc.free(self.data);
_ = self.image.unref();
self.* = undefined;
}
/// Write the data in this drawing to the atlas.
pub fn writeAtlas(self: *Canvas, alloc: Allocator, atlas: *font.Atlas) !font.Atlas.Region {
assert(atlas.format == .greyscale);
const width = @intCast(u32, self.image.getWidth());
const height = @intCast(u32, self.image.getHeight());
const region = try atlas.reserve(alloc, width, height);
if (region.width > 0 and region.height > 0) {
const depth = atlas.format.depth();
// Convert our []u32 to []u8 since we use 8bpp formats
const stride = self.image.getStride();
const data = @alignCast(
@alignOf(u8),
@ptrCast([*]u8, self.data.ptr)[0 .. self.data.len * 4],
);
// We can avoid a buffer copy if our atlas width and bitmap
// width match and the bitmap pitch is just the width (meaning
// the data is tightly packed).
const needs_copy = !(width * depth == stride);
// If we need to copy the data, we copy it into a temporary buffer.
const buffer = if (needs_copy) buffer: {
var temp = try alloc.alloc(u8, width * height * depth);
var dst_ptr = temp;
var src_ptr = data.ptr;
var i: usize = 0;
while (i < height) : (i += 1) {
std.mem.copy(u8, dst_ptr, src_ptr[0 .. width * depth]);
dst_ptr = dst_ptr[width * depth ..];
src_ptr += @intCast(usize, stride);
}
break :buffer temp;
} else data[0..(width * height * depth)];
defer if (buffer.ptr != data.ptr) alloc.free(buffer);
// Write the glyph information into the atlas
assert(region.width == width);
assert(region.height == height);
atlas.set(region, buffer);
}
return region;
}
/// Draw and fill a rectangle. This is the main primitive for drawing
/// lines as well (which are just generally skinny rectangles...)
pub fn rect(self: *Canvas, v: Rect, color: Color) void {
const boxes = &[_]pixman.Box32{
.{
.x1 = @intCast(i32, v.x),
.y1 = @intCast(i32, v.y),
.x2 = @intCast(i32, v.x + @intCast(i32, v.width)),
.y2 = @intCast(i32, v.y + @intCast(i32, v.height)),
},
};
self.image.fillBoxes(.src, color.pixmanColor(), boxes) catch {};
}
/// Draw and fill a trapezoid.
pub fn trapezoid(self: *Canvas, t: Trapezoid) void {
self.image.rasterizeTrapezoid(.{
.top = pixman.Fixed.init(t.top),
.bottom = pixman.Fixed.init(t.bottom),
.left = .{
.p1 = .{
.x = pixman.Fixed.init(t.left.p1.x),
.y = pixman.Fixed.init(t.left.p1.y),
},
.p2 = .{
.x = pixman.Fixed.init(t.left.p2.x),
.y = pixman.Fixed.init(t.left.p2.y),
},
},
.right = .{
.p1 = .{
.x = pixman.Fixed.init(t.right.p1.x),
.y = pixman.Fixed.init(t.right.p1.y),
},
.p2 = .{
.x = pixman.Fixed.init(t.right.p2.x),
.y = pixman.Fixed.init(t.right.p2.y),
},
},
}, 0, 0);
}
/// Draw and fill a triangle.
pub fn triangle(self: *Canvas, t: Triangle, color: Color) void {
const tris = &[_]pixman.Triangle{
.{
.p1 = .{ .x = pixman.Fixed.init(t.p1.x), .y = pixman.Fixed.init(t.p1.y) },
.p2 = .{ .x = pixman.Fixed.init(t.p2.x), .y = pixman.Fixed.init(t.p2.y) },
.p3 = .{ .x = pixman.Fixed.init(t.p3.x), .y = pixman.Fixed.init(t.p3.y) },
},
};
const src = pixman.Image.createSolidFill(color.pixmanColor()) catch return;
defer _ = src.unref();
self.image.compositeTriangles(.over, src, .a8, 0, 0, 0, 0, tris);
}
/// Composite one image on another.
pub fn composite(self: *Canvas, op: CompositionOp, src: *const Canvas, dest: Rect) void {
self.image.composite(
op.pixmanOp(),
src.image,
null,
0,
0,
0,
0,
@intCast(i16, dest.x),
@intCast(i16, dest.y),
@intCast(u16, dest.width),
@intCast(u16, dest.height),
);
}
/// Returns a copy of the raw pixel data in A8 format. The returned value
/// must be freed by the caller. The returned data always has a stride
/// exactly equivalent to the width.
pub fn getData(self: *const Canvas, alloc: Allocator) ![]u8 {
const width = @intCast(u32, self.image.getWidth());
const height = @intCast(u32, self.image.getHeight());
var result = try alloc.alloc(u8, height * width);
errdefer alloc.free(result);
// We want to convert our []u32 to []u8 since we use an 8bpp format
var data_u32 = self.image.getData();
const len_u8 = data_u32.len * 4;
var real_data = @alignCast(@alignOf(u8), @ptrCast([*]u8, data_u32.ptr)[0..len_u8]);
const real_stride = self.image.getStride();
// Convert our strided data
var r: u32 = 0;
while (r < height) : (r += 1) {
var c: u32 = 0;
while (c < width) : (c += 1) {
const src = r * @intCast(usize, real_stride) + c;
const dst = (r * c) + c;
result[dst] = real_data[src];
}
}
return result;
}
};

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@ -78,7 +78,7 @@ const Draw = struct {
fn drawSingle(self: Draw, canvas: *font.sprite.Canvas) void {
canvas.rect(.{
.x = 0,
.y = self.pos,
.y = @intCast(i32, self.pos),
.width = self.width,
.height = self.thickness,
}, .on);
@ -88,14 +88,14 @@ const Draw = struct {
fn drawDouble(self: Draw, canvas: *font.sprite.Canvas) void {
canvas.rect(.{
.x = 0,
.y = self.pos,
.y = @intCast(i32, self.pos),
.width = self.width,
.height = self.thickness,
}, .on);
canvas.rect(.{
.x = 0,
.y = self.pos + (self.thickness * 2),
.y = @intCast(i32, self.pos + (self.thickness * 2)),
.width = self.width,
.height = self.thickness,
}, .on);
@ -108,8 +108,8 @@ const Draw = struct {
var i: u32 = 0;
while (i < dot_count) : (i += 2) {
canvas.rect(.{
.x = i * dot_width,
.y = self.pos,
.x = @intCast(i32, i * dot_width),
.y = @intCast(i32, self.pos),
.width = dot_width,
.height = self.thickness,
}, .on);
@ -123,8 +123,8 @@ const Draw = struct {
var i: u32 = 0;
while (i < dash_count) : (i += 2) {
canvas.rect(.{
.x = i * dash_width,
.y = self.pos,
.x = @intCast(i32, i * dash_width),
.y = @intCast(i32, self.pos),
.width = dash_width,
.height = self.thickness,
}, .on);
@ -157,8 +157,8 @@ const Draw = struct {
while (row < self.thickness) : (row += 1) {
const y1 = @min(row + y + vertical, y_max);
canvas.rect(.{
.x = x,
.y = y1,
.x = @intCast(i32, x),
.y = @intCast(i32, y1),
.width = 1,
.height = 1,
}, .on);