tiny.gui.paint.cpu.geometry

1const std = @import("std");23const gui = @import("../../root.zig");4const paint_root = @import("../root.zig");56const Command = paint_root.command.Command;7const Rect = gui.layout.Rect;89pub const Bounds = struct {10    x0: u32,11    y0: u32,12    x1: u32,13    y1: u32,14};1516pub const Region = struct {17    x: u32 = 0,18    y: u32 = 0,19    width: u32 = 0,20    height: u32 = 0,2122    pub fn full(width: u32, height: u32) Region {23        return .{ .width = width, .height = height };24    }2526    pub fn pixelCount(self: Region) usize {27        return @as(usize, self.width) * @as(usize, self.height);28    }2930    pub fn clamped(self: Region, width: u32, height: u32) Region {31        if (self.x >= width or self.y >= height) return .{ .x = self.x, .y = self.y };32        return .{33            .x = self.x,34            .y = self.y,35            .width = @min(self.width, width - self.x),36            .height = @min(self.height, height - self.y),37        };38    }39};4041pub fn clippedBounds(width: u32, height: u32, paint: Command, region: Region) ?Bounds {42    const bounds = paint_root.command.bounds(paint);43    const region_rect = regionRect(region);44    const x0 = floorClamp(@max(@max(bounds.x, paint.clip.x), region_rect.x), width);45    const y0 = floorClamp(@max(@max(bounds.y, paint.clip.y), region_rect.y), height);46    const x1 = ceilClamp(@min(@min(bounds.x + bounds.width, paint.clip.x + paint.clip.width), region_rect.x + region_rect.width), width);47    const y1 = ceilClamp(@min(@min(bounds.y + bounds.height, paint.clip.y + paint.clip.height), region_rect.y + region_rect.height), height);48    if (x0 >= x1 or y0 >= y1) return null;49    return .{ .x0 = x0, .y0 = y0, .x1 = x1, .y1 = y1 };50}5152pub fn regionRect(region: Region) Rect {53    return .{54        .x = @floatFromInt(region.x),55        .y = @floatFromInt(region.y),56        .width = @floatFromInt(region.width),57        .height = @floatFromInt(region.height),58    };59}6061pub fn floorClamp(value: f32, limit: u32) u32 {62    if (std.math.isNan(value) or value <= 0) return 0;63    if (!std.math.isFinite(value)) return limit;64    const floored = @floor(value);65    if (floored >= @as(f32, @floatFromInt(limit))) return limit;66    return @intFromFloat(floored);67}6869pub fn ceilClamp(value: f32, limit: u32) u32 {70    if (std.math.isNan(value) or value <= 0) return 0;71    if (!std.math.isFinite(value)) return limit;72    const ceiled = @ceil(value);73    if (ceiled >= @as(f32, @floatFromInt(limit))) return limit;74    return @intFromFloat(ceiled);75}7677pub fn inside(rect: Rect, x: f32, y: f32) bool {78    return x >= rect.x and y >= rect.y and x < rect.x + rect.width and y < rect.y + rect.height;79}8081pub fn insideRounded(rect: Rect, radius: f32, x: f32, y: f32) bool {82    if (!inside(rect, x, y)) return false;83    const clamped = clampedRadius(rect, radius);84    if (clamped <= 0) return true;85    const inner_x0 = rect.x + clamped;86    const inner_y0 = rect.y + clamped;87    const inner_x1 = rect.x + rect.width - clamped;88    const inner_y1 = rect.y + rect.height - clamped;89    const cx = @max(inner_x0, @min(x, inner_x1));90    const cy = @max(inner_y0, @min(y, inner_y1));91    const dx = x - cx;92    const dy = y - cy;93    return dx * dx + dy * dy <= clamped * clamped;94}9596pub fn roundedRectOutsideDistance(rect: Rect, radius: f32, x: f32, y: f32) f32 {97    const clamped = clampedRadius(rect, radius);98    const inner_x0 = rect.x + clamped;99    const inner_y0 = rect.y + clamped;100    const inner_x1 = rect.x + rect.width - clamped;101    const inner_y1 = rect.y + rect.height - clamped;102    const cx = @max(inner_x0, @min(x, inner_x1));103    const cy = @max(inner_y0, @min(y, inner_y1));104    const dx = x - cx;105    const dy = y - cy;106    return @max(@sqrt(dx * dx + dy * dy) - clamped, 0);107}108109pub fn clampedRadius(rect: Rect, radius: f32) f32 {110    return @min(@max(radius, 0), @min(rect.width, rect.height) * 0.5);111}112113pub fn inset(rect: Rect, value: f32) Rect {114    return .{115        .x = rect.x + value,116        .y = rect.y + value,117        .width = @max(rect.width - value * 2, 0),118        .height = @max(rect.height - value * 2, 0),119    };120}121122pub fn finiteRects(rect: Rect, clip: Rect) bool {123    return !std.math.isNan(rect.x) and !std.math.isNan(rect.y) and124        !std.math.isNan(rect.width) and !std.math.isNan(rect.height) and125        !std.math.isNan(clip.x) and !std.math.isNan(clip.y) and126        !std.math.isNan(clip.width) and !std.math.isNan(clip.height);127}128129test "floorClamp and ceilClamp bound non-finite and negative values" {130    try std.testing.expectEqual(@as(u32, 0), floorClamp(-3.5, 10));131    try std.testing.expectEqual(@as(u32, 0), floorClamp(std.math.nan(f32), 10));132    try std.testing.expectEqual(@as(u32, 10), floorClamp(400, 10));133    try std.testing.expectEqual(@as(u32, 4), ceilClamp(3.5, 10));134    try std.testing.expectEqual(@as(u32, 0), ceilClamp(std.math.inf(f32) * -1, 10));135    try std.testing.expectEqual(@as(u32, 10), ceilClamp(std.math.inf(f32), 10));136    try std.testing.expectEqual(@as(u32, 10), floorClamp(std.math.inf(f32), 10));137    try std.testing.expectEqual(@as(u32, 0), floorClamp(std.math.inf(f32) * -1, 10));138}139140test "clippedBounds culls positive-infinite geometry instead of leaking outside the region" {141    const inf = std.math.inf(f32);142    const region = Region{ .x = 3, .y = 2, .width = 4, .height = 4 };143    const command = Command{144        .kind = .fill,145        .rect = .{ .x = inf, .y = 1, .width = 5, .height = 5 },146        .clip = .{ .x = 0, .y = 0, .width = 10, .height = 8 },147        .color = .{ .r = 1, .g = 2, .b = 3, .a = 255 },148    };149    try std.testing.expectEqual(@as(?Bounds, null), clippedBounds(10, 8, command, region));150151    const clipped_away = Command{152        .kind = .fill,153        .rect = .{ .x = 1, .y = 1, .width = 5, .height = 5 },154        .clip = .{ .x = inf, .y = 0, .width = 10, .height = 8 },155        .color = .{ .r = 1, .g = 2, .b = 3, .a = 255 },156    };157    try std.testing.expectEqual(@as(?Bounds, null), clippedBounds(10, 8, clipped_away, region));158}159160test "insideRounded keeps straight bands and rejects corners" {161    const rect = Rect{ .x = 0, .y = 0, .width = 10, .height = 10 };162    try std.testing.expect(insideRounded(rect, 3, 5, 0.1));163    try std.testing.expect(!insideRounded(rect, 3, 0.2, 0.2));164    try std.testing.expect(insideRounded(rect, 3, 3, 3));165}

1pub const geometry = render.geometry;