ПРавильные прямоугольники

This reverts commit 68a4647e3f.

.vscode/launch.json

@@ -10,5 +10,12 @@
             "cwd": "${workspaceFolder}",
             "preLaunchTask": "zig: build"
         },
+        {
+            "name": "Zig: Debug (gdb)",
+            "type": "gdb",
+            "request": "launch",
+            "program": "${workspaceFolder}/zig-out/bin/Zivro",
+            "preLaunchTask": "zig: build"
+        },
     ]
 }

.vscode/settings.json

@@ -0,0 +1,7 @@
+{
+    "zig.testArgs": [
+        "build",
+        "test",
+        "-Dtest-filter=${filter}"
+    ]
+}

.vscode/tasks.json

@@ -10,11 +10,6 @@
                 "isDefault": true
             },
             "problemMatcher": ["$gcc"],
-            "presentation": {
-                "reveal": "always",
-                "panel": "shared",
-                "showReuseMessage": true
-            }
         }
     ]
 }

build.zig

@@ -34,7 +34,16 @@ pub fn build(b: *std.Build) void {
     }
 
     const exe_tests = b.addTest(.{
-        .root_module = exe.root_module,
+        .root_module = b.createModule(.{
+            .root_source_file = b.path("src/tests.zig"),
+            .target = target,
+            .optimize = optimize,
+
+            .imports = &.{
+                .{ .name = "dvui", .module = dvui_dep.module("dvui_sdl3") },
+                .{ .name = "sdl-backend", .module = dvui_dep.module("sdl3") },
+            },
+        }),
     });
 
     const run_exe_tests = b.addRunArtifact(exe_tests);

src/Canvas.zig

@@ -0,0 +1,135 @@
+const std = @import("std");
+const builtin = @import("builtin");
+const dvui = @import("dvui");
+const Document = @import("models/Document.zig");
+const RenderEngine = @import("render/RenderEngine.zig").RenderEngine;
+const ImageRect = @import("models/rasterization_models.zig").ImageRect;
+const Size = dvui.Size;
+const Color = dvui.Color;
+
+const Canvas = @This();
+
+allocator: std.mem.Allocator,
+texture: ?dvui.Texture = null,
+size: Size = .{ .w = 800, .h = 600 },
+pos: dvui.Point = dvui.Point{ .x = 0, .y = 0 },
+scroll: dvui.ScrollInfo = .{
+    .vertical = .auto,
+    .horizontal = .auto,
+},
+native_scaling: bool = false,
+gradient_start: Color.PMA = .{ .r = 0, .g = 0, .b = 0, .a = 255 },
+gradient_end: Color.PMA = .{ .r = 255, .g = 255, .b = 255, .a = 255 },
+document: ?*Document = null,
+render_engine: RenderEngine,
+_visible_rect: ?ImageRect = null,
+_zoom: f32 = 1,
+
+pub fn init(allocator: std.mem.Allocator, engine: RenderEngine) Canvas {
+    return .{
+        .allocator = allocator,
+        .render_engine = engine,
+    };
+}
+
+pub fn deinit(self: *Canvas) void {
+    if (self.texture) |texture| {
+        dvui.Texture.destroyLater(texture);
+        self.texture = null;
+    }
+}
+
+/// Заполнить canvas градиентом
+pub fn redrawExample(self: *Canvas) !void {
+    const full = self.getScaledImageSize();
+
+    const vis: ImageRect = self._visible_rect orelse ImageRect{ .x = 0, .y = 0, .w = 0, .h = 0 };
+
+    if (vis.w == 0 or vis.h == 0) {
+        if (self.texture) |tex| {
+            dvui.Texture.destroyLater(tex);
+            self.texture = null;
+        }
+        return;
+    }
+
+    const new_texture = self.render_engine.example(.{ .w = full.w, .h = full.h }, vis) catch null;
+
+    if (new_texture) |tex| {
+        // Удалить старую текстуру
+        if (self.texture) |old_tex| {
+            dvui.Texture.destroyLater(old_tex);
+        }
+
+        self.texture = tex;
+    }
+}
+
+// Ресетнуть example изображение в renderEngine
+pub fn exampleReset(self: *Canvas) !void {
+    self.render_engine.exampleReset();
+    try self.redrawExample();
+}
+
+pub fn setZoom(self: *Canvas, value: f32) void {
+    self._zoom = @max(value, 0.01);
+}
+
+pub fn addZoom(self: *Canvas, value: f32) void {
+    self._zoom += value;
+    self._zoom = @max(self._zoom, 0.01);
+}
+
+pub fn getScaledImageSize(self: Canvas) ImageRect {
+    return .{
+        .x = @intFromFloat(self.pos.x),
+        .y = @intFromFloat(self.pos.y),
+        .w = @intFromFloat(self.size.w * self._zoom),
+        .h = @intFromFloat(self.size.h * self._zoom),
+    };
+}
+
+/// Обновить видимую часть изображения (в пикселях холста) и сохранить в `visible_rect`.
+///
+/// `viewport` и `scroll_offset` ожидаются в *physical* пикселях (т.е. уже умноженные на windowNaturalScale).
+///
+/// После обновления (или если текстуры ещё нет) перерисовывает текстуру, чтобы она содержала только видимую часть.
+pub fn updateVisibleImageRect(self: *Canvas, viewport: dvui.Rect, scroll_offset: dvui.Point) !void {
+    const next = computeVisibleImageRect(self.*, viewport, scroll_offset);
+    var changed = false;
+    if (self._visible_rect) |vis| {
+        changed |= next.x != vis.x or next.y != vis.y or next.w != vis.w or next.h != vis.h;
+    }
+    self._visible_rect = next;
+    if (changed) {
+        std.debug.print("Visible Image Rect: {{ x: {}, y: {}, w: {}, h: {} }}\n", .{ next.x, next.y, next.w, next.h });
+    }
+    if (changed or self.texture == null) {
+        try self.redrawExample();
+    }
+}
+
+fn computeVisibleImageRect(self: Canvas, viewport: dvui.Rect, scroll_offset: dvui.Point) ImageRect {
+    const image_rect = self.getScaledImageSize();
+
+    const img_w: u32 = image_rect.w;
+    const img_h: u32 = image_rect.h;
+
+    // Видимый размер всегда равен размеру viewport, но не больше холста
+    const vis_w: u32 = @min(@as(u32, @intFromFloat(viewport.w)), img_w);
+    const vis_h: u32 = @min(@as(u32, @intFromFloat(viewport.h)), img_h);
+
+    // Вычисляем x и y на основе scroll_offset, clamped чтобы не выходить за границы
+    const raw_x: i64 = @intFromFloat(scroll_offset.x - @as(f32, @floatFromInt(image_rect.x)));
+    const raw_y: i64 = @intFromFloat(scroll_offset.y - @as(f32, @floatFromInt(image_rect.y)));
+
+    const vis_x: u32 = @intCast(std.math.clamp(raw_x, 0, @as(i64, img_w) - @as(i64, vis_w)));
+    const vis_y: u32 = @intCast(std.math.clamp(raw_y, 0, @as(i64, img_h) - @as(i64, vis_h)));
+
+    return ImageRect{
+        .x = vis_x,
+        .y = vis_y,
+        .w = vis_w,
+        .h = vis_h,
+    };
+}

src/WindowContext.zig

@@ -0,0 +1,30 @@
+const std = @import("std");
+const Canvas = @import("Canvas.zig");
+const CpuRenderEngine = @import("render/CpuRenderEngine.zig");
+
+const WindowContext = @This();
+
+allocator: std.mem.Allocator,
+canvas: Canvas,
+cpu_render: *CpuRenderEngine,
+frame_index: u64,
+
+pub fn init(allocator: std.mem.Allocator) !WindowContext {
+    var self: WindowContext = undefined;
+    self.allocator = allocator;
+
+    self.cpu_render = try allocator.create(CpuRenderEngine);
+    errdefer allocator.destroy(self.cpu_render);
+    self.cpu_render.* = CpuRenderEngine.init(allocator, .Squares);
+
+    self.canvas = Canvas.init(allocator, self.cpu_render.renderEngine());
+
+    self.frame_index = 0;
+
+    return self;
+}
+
+pub fn deinit(self: *WindowContext) void {
+    self.canvas.deinit();
+    self.allocator.destroy(self.cpu_render);
+}

src/main.zig

@@ -1,215 +1,253 @@
 const std = @import("std");
 const builtin = @import("builtin");
 const dvui = @import("dvui");
+const dvui_ext = @import("ui/dvui_ext.zig");
 const SDLBackend = @import("sdl-backend");
-
+const Document = @import("models/Document.zig");
-const WindowContext = struct {
+const ImageRect = @import("models/rasterization_models.zig").ImageRect;
-    backend: SDLBackend,
+const WindowContext = @import("WindowContext.zig");
-    window: dvui.Window,
+const sdl_c = SDLBackend.c;
-    title: [:0]u8,
+const Allocator = std.mem.Allocator;
-    id: usize,
+const Color = dvui.Color;
-
-    fn deinit(self: *WindowContext, allocator: std.mem.Allocator, last_backend: bool) void {
-        self.window.deinit();
-
-        if (last_backend) {
-            self.backend.deinit();
-        } else {
-            destroyBackendKeepingSDL(&self.backend);
-        }
-
-        allocator.free(self.title);
-        self.* = undefined;
-    }
-};
 
 pub fn main() !void {
-    if (@import("builtin").os.tag == .windows) {
-        // on windows graphical apps have no console, so output goes to nowhere - attach it manually. related: https://github.com/ziglang/zig/issues/4196
-        dvui.Backend.Common.windowsAttachConsole() catch {};
-    }
-    SDLBackend.enableSDLLogging();
-    std.log.info("SDL version: {f}", .{SDLBackend.getSDLVersion()});
-
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
-    defer _ = gpa.deinit();
     const allocator = gpa.allocator();
 
-    var windows = try std.ArrayList(*WindowContext).initCapacity(allocator, 0);
+    var backend = try SDLBackend.initWindow(.{
-    defer {
+        .allocator = allocator,
-        for (windows.items, 0..) |ctx, i| {
+        .size = .{ .w = 800.0, .h = 600.0 },
-            const last = i + 1 == windows.items.len;
+        .title = "My DVUI App",
-            ctx.deinit(allocator, last);
+        .vsync = true,
-            allocator.destroy(ctx);
+    });
-        }
+    defer backend.deinit();
-        windows.deinit(allocator);
-    }
 
-    var next_window_id: usize = 1;
+    var win = try dvui.Window.init(@src(), allocator, backend.backend(), .{
-    const first_ctx = try createWindow(allocator, next_window_id);
+        .theme = switch (backend.preferredColorScheme() orelse .light) {
-    next_window_id += 1;
+            .light => dvui.Theme.builtin.adwaita_light,
-    try windows.append(allocator, first_ctx);
+            .dark => dvui.Theme.builtin.adwaita_dark,
+        },
+    });
+    defer win.deinit();
+
+    var ctx = try WindowContext.init(allocator);
+    defer ctx.deinit();
 
     var interrupted = false;
-
     main_loop: while (true) {
-        if (windows.items.len == 0) break :main_loop;
-
-        const saw_events = try pumpEvents(&windows);
-
-        var min_wait_event_micros: u32 = std.math.maxInt(u32);
-        var idx: usize = 0;
-        while (idx < windows.items.len) {
-            const ctx = windows.items[idx];
-
         // beginWait coordinates with waitTime below to run frames only when needed
-            const nstime = ctx.window.beginWait(interrupted);
+        const nstime = win.beginWait(interrupted);
+
         // marks the beginning of a frame for dvui, can call dvui functions after this
-            try ctx.window.begin(nstime);
+        try win.begin(nstime);
+
+        // send all SDL events to dvui for processing
+        try backend.addAllEvents(&win);
 
         // if dvui widgets might not cover the whole window, then need to clear
         // the previous frame's render
-            _ = SDLBackend.c.SDL_SetRenderDrawColor(ctx.backend.renderer, 0, 0, 0, 255);
+        _ = SDLBackend.c.SDL_SetRenderDrawColor(backend.renderer, 0, 0, 0, 255);
-            _ = SDLBackend.c.SDL_RenderClear(ctx.backend.renderer);
+        _ = SDLBackend.c.SDL_RenderClear(backend.renderer);
 
-            const keep_open = try gui_frame(ctx, allocator, &windows, &next_window_id);
+        const keep_running = gui_frame(&ctx);
-            if (!keep_open) {
+        if (!keep_running) break :main_loop;
-                closeWindow(&windows, allocator, idx);
-                continue;
-            }
 
         // marks end of dvui frame, don't call dvui functions after this
         // - sends all dvui stuff to backend for rendering, must be called before renderPresent()
-            const end_micros = try ctx.window.end(.{});
+        const end_micros = try win.end(.{});
 
         // cursor management
-            try ctx.backend.setCursor(ctx.window.cursorRequested());
+        try backend.setCursor(win.cursorRequested());
-            try ctx.backend.textInputRect(ctx.window.textInputRequested());
+        try backend.textInputRect(win.textInputRequested());
 
         // render frame to OS
-            try ctx.backend.renderPresent();
+        try backend.renderPresent();
 
         // waitTime and beginWait combine to achieve variable framerates
-            const wait_event_micros = ctx.window.waitTime(end_micros);
+        const wait_event_micros = win.waitTime(end_micros);
-            min_wait_event_micros = @min(min_wait_event_micros, wait_event_micros);
+        interrupted = try backend.waitEventTimeout(wait_event_micros);
-
-            idx += 1;
-        }
-
-        if (windows.items.len == 0) break :main_loop;
-
-        interrupted = saw_events or try windows.items[0].backend.waitEventTimeout(min_wait_event_micros);
     }
 }
 
-fn createWindow(allocator: std.mem.Allocator, id: usize) !*WindowContext {
+fn gui_frame(ctx: *WindowContext) bool {
-    var ctx = try allocator.create(WindowContext);
+    const canvas = &ctx.canvas;
-    errdefer allocator.destroy(ctx);
+    const ctrl: bool = dvui.currentWindow().modifiers.control();
 
-    ctx.id = id;
+    for (dvui.events()) |*e| {
-
-    const title_bytes = try std.fmt.allocPrint(allocator, "My DVUI App #{d}", .{id});
-    defer allocator.free(title_bytes);
-
-    ctx.title = try allocator.allocSentinel(u8, title_bytes.len, 0);
-    @memcpy(ctx.title[0..title_bytes.len], title_bytes);
-
-    ctx.backend = try SDLBackend.initWindow(.{
-        .allocator = allocator,
-        .size = .{ .w = 800.0, .h = 600.0 },
-        .title = ctx.title,
-        .vsync = true,
-    });
-    errdefer destroyBackendKeepingSDL(&ctx.backend);
-
-    const theme = switch (ctx.backend.preferredColorScheme() orelse .light) {
-        .light => dvui.Theme.builtin.adwaita_light,
-        .dark => dvui.Theme.builtin.adwaita_dark,
-    };
-
-    ctx.window = try dvui.Window.init(@src(), allocator, ctx.backend.backend(), .{ .theme = theme });
-    errdefer ctx.window.deinit();
-
-    return ctx;
-}
-
-fn closeWindow(windows: *std.ArrayList(*WindowContext), allocator: std.mem.Allocator, idx: usize) void {
-    const last = windows.items.len == 1;
-    const ctx = windows.swapRemove(idx);
-    ctx.deinit(allocator, last);
-    allocator.destroy(ctx);
-}
-
-fn destroyBackendKeepingSDL(backend: *SDLBackend) void {
-    SDLBackend.c.SDL_DestroyRenderer(backend.renderer);
-    SDLBackend.c.SDL_DestroyWindow(backend.window);
-    backend.we_own_window = false;
-    backend.deinit();
-}
-
-fn windowId(ctx: *WindowContext) u32 {
-    return @intCast(SDLBackend.c.SDL_GetWindowID(ctx.backend.window));
-}
-
-fn eventWindowId(event: SDLBackend.c.SDL_Event) ?u32 {
-    return switch (event.type) {
-        if (SDLBackend.sdl3) SDLBackend.c.SDL_EVENT_KEY_DOWN else SDLBackend.c.SDL_KEYDOWN => @intCast(event.key.windowID),
-        if (SDLBackend.sdl3) SDLBackend.c.SDL_EVENT_KEY_UP else SDLBackend.c.SDL_KEYUP => @intCast(event.key.windowID),
-        if (SDLBackend.sdl3) SDLBackend.c.SDL_EVENT_TEXT_INPUT else SDLBackend.c.SDL_TEXTINPUT => @intCast(event.text.windowID),
-        if (SDLBackend.sdl3) SDLBackend.c.SDL_EVENT_TEXT_EDITING else SDLBackend.c.SDL_TEXTEDITING => @intCast(event.edit.windowID),
-        if (SDLBackend.sdl3) SDLBackend.c.SDL_EVENT_MOUSE_MOTION else SDLBackend.c.SDL_MOUSEMOTION => @intCast(event.motion.windowID),
-        if (SDLBackend.sdl3) SDLBackend.c.SDL_EVENT_MOUSE_BUTTON_DOWN else SDLBackend.c.SDL_MOUSEBUTTONDOWN => @intCast(event.button.windowID),
-        if (SDLBackend.sdl3) SDLBackend.c.SDL_EVENT_MOUSE_BUTTON_UP else SDLBackend.c.SDL_MOUSEBUTTONUP => @intCast(event.button.windowID),
-        if (SDLBackend.sdl3) SDLBackend.c.SDL_EVENT_MOUSE_WHEEL else SDLBackend.c.SDL_MOUSEWHEEL => @intCast(event.wheel.windowID),
-        if (SDLBackend.sdl3) SDLBackend.c.SDL_EVENT_WINDOW_CLOSE_REQUESTED else SDLBackend.c.SDL_WINDOWEVENT => @intCast(event.window.windowID),
-        else => null,
-    };
-}
-
-fn pumpEvents(windows: *std.ArrayList(*WindowContext)) !bool {
-    var event: SDLBackend.c.SDL_Event = undefined;
-    const poll_got_event = if (SDLBackend.sdl3) true else 1;
-    var saw_event = false;
-
-    while (SDLBackend.c.SDL_PollEvent(&event) == poll_got_event) {
-        saw_event = true;
-
-        if (eventWindowId(event)) |wid| {
-            for (windows.items) |ctx| {
-                if (windowId(ctx) == wid) {
-                    _ = try ctx.backend.addEvent(&ctx.window, event);
-                    break;
-                }
-            }
-        } else {
-            // broadcast events without a window target (like SDL_QUIT)
-            for (windows.items) |ctx| {
-                _ = try ctx.backend.addEvent(&ctx.window, event);
-            }
-        }
-    }
-
-    return saw_event;
-}
-
-fn gui_frame(ctx: *WindowContext, allocator: std.mem.Allocator, windows: *std.ArrayList(*WindowContext), next_window_id: *usize) !bool {
-    for (ctx.window.events.items) |*e| {
         if (e.evt == .window and e.evt.window.action == .close) return false;
-        // Treat SDL_QUIT as a global request; ignore here so other windows keep running.
+        if (e.evt == .app and e.evt.app.action == .quit) return false;
     }
 
-    var root = dvui.box(@src(), .{ .dir = .vertical }, .{ .expand = .both, .padding = dvui.Rect.all(12), .background = true, .style = .window });
+    const root = dvui.box(
+        @src(),
+        .{ .dir = .horizontal },
+        .{ .expand = .both, .background = true, .style = .window },
+    );
     defer root.deinit();
 
-    dvui.label(@src(), "Window #{d}", .{ctx.id}, .{ .font_style = .title_2 });
+    // Левая панель с фиксированной шириной
-    dvui.label(@src(), "Open windows: {d}", .{windows.items.len}, .{});
+    var left_panel = dvui.box(@src(), .{ .dir = .vertical }, .{ .expand = .vertical, .min_size_content = .{ .w = 200 }, .background = true });
-
+    {
-    if (dvui.button(@src(), "New window", .{}, .{})) {
+        dvui.label(@src(), "Tools", .{}, .{});
-        const id = next_window_id.*;
+        if (dvui.button(@src(), "Fill Random Color", .{}, .{}) or ctx.frame_index == 0) {
-        next_window_id.* += 1;
+            canvas.exampleReset() catch |err| {
-        const new_ctx = try createWindow(allocator, id);
+                std.debug.print("Error reset example: {}\n", .{err});
-        try windows.append(allocator, new_ctx);
+            };
+            canvas.pos = .{ .x = 400, .y = 400 };
         }
+        if (dvui.checkbox(@src(), &canvas.native_scaling, "Scaling", .{})) {}
+        if (dvui.button(@src(), if (ctx.cpu_render.type == .Gradient) "Gradient" else "Squares", .{}, .{})) {
+            if (ctx.cpu_render.type == .Gradient) {
+                ctx.cpu_render.type = .Squares;
+            } else {
+                ctx.cpu_render.type = .Gradient;
+            }
+            canvas.redrawExample() catch {};
+        }
+    }
+    left_panel.deinit();
+
+    // Правая панель - занимает оставшееся пространство
+    const back = dvui.box(
+        @src(),
+        .{ .dir = .horizontal },
+        .{ .expand = .both, .padding = dvui.Rect.all(12), .background = true },
+    );
+    {
+        const fill_color = Color.black.opacity(0.25);
+        var right_panel = dvui.box(
+            @src(),
+            .{ .dir = .vertical },
+            .{
+                .expand = .both,
+                .background = true,
+                .padding = dvui.Rect.all(5),
+                .corner_radius = dvui.Rect.all(24),
+                .color_fill = fill_color,
+            },
+        );
+        {
+            var textured = dvui_ext.texturedBox(right_panel.data().contentRectScale(), dvui.Rect.all(20));
+            {
+                var overlay = dvui.overlay(
+                    @src(),
+                    .{ .expand = .both },
+                );
+                {
+                    var scroll = dvui.scrollArea(
+                        @src(),
+                        .{
+                            .scroll_info = &canvas.scroll,
+                            .vertical_bar = .auto,
+                            .horizontal_bar = .auto,
+                        },
+                        .{
+                            .expand = .both,
+                            .background = false,
+                        },
+                    );
+                    {
+                        const natural_scale = if (canvas.native_scaling) 1 else dvui.windowNaturalScale();
+                        const img_size = canvas.getScaledImageSize();
+
+                        // Получить viewport и scroll offset
+                        const viewport_rect = scroll.data().contentRect();
+                        const scroll_current = dvui.Point{ .x = canvas.scroll.viewport.x, .y = canvas.scroll.viewport.y };
+
+                        // viewport_rect/scroll_current — в natural единицах.
+                        // Для расчёта видимой области в пикселях изображения переводим в physical.
+                        const viewport_px = dvui.Rect{
+                            .x = viewport_rect.x * natural_scale,
+                            .y = viewport_rect.y * natural_scale,
+                            .w = viewport_rect.w * natural_scale,
+                            .h = viewport_rect.h * natural_scale,
+                        };
+                        const scroll_px = dvui.Point{
+                            .x = scroll_current.x * natural_scale,
+                            .y = scroll_current.y * natural_scale,
+                        };
+
+                        canvas.updateVisibleImageRect(viewport_px, scroll_px) catch |err| {
+                            std.debug.print("updateVisibleImageRect error: {}\n", .{err});
+                        };
+
+                        // `canvas.texture` contains ONLY the visible part.
+                        // If we render it inside a widget sized as the full image, dvui will stretch it.
+                        // Instead: create a scroll content surface sized like the full image, then place
+                        // the visible texture at the correct offset at 1:1.
+                        const content_w_px: u32 = img_size.x + img_size.w;
+                        const content_h_px: u32 = img_size.y + img_size.h;
+                        const content_w = @as(f32, @floatFromInt(content_w_px)) / natural_scale;
+                        const content_h = @as(f32, @floatFromInt(content_h_px)) / natural_scale;
+
+                        var canvas_layer = dvui.overlay(
+                            @src(),
+                            .{ .min_size_content = .{ .w = content_w, .h = content_h }, .background = false },
+                        );
+                        {
+                            if (canvas.texture) |tex| {
+                                const vis = canvas._visible_rect orelse ImageRect{ .x = 0, .y = 0, .w = 0, .h = 0 };
+                                const left = @as(f32, @floatFromInt(img_size.x + vis.x)) / natural_scale;
+                                const top = @as(f32, @floatFromInt(img_size.y + vis.y)) / natural_scale;
+
+                                _ = dvui.image(
+                                    @src(),
+                                    .{ .source = .{ .texture = tex } },
+                                    .{
+                                        .background = false,
+                                        .expand = .none,
+                                        .gravity_x = 0.0,
+                                        .gravity_y = 0.0,
+                                        .margin = .{ .x = left, .y = top, .w = canvas.pos.x, .h = canvas.pos.y },
+                                        .min_size_content = .{
+                                            .w = @as(f32, @floatFromInt(vis.w)) / natural_scale,
+                                            .h = @as(f32, @floatFromInt(vis.h)) / natural_scale,
+                                        },
+                                        .max_size_content = .{
+                                            .w = @as(f32, @floatFromInt(vis.w)) / natural_scale,
+                                            .h = @as(f32, @floatFromInt(vis.h)) / natural_scale,
+                                        },
+                                    },
+                                );
+                            }
+                        }
+                        canvas_layer.deinit();
+
+                        // Заблокировать события скролла, если нажат ctrl
+                        if (ctrl) {
+                            for (dvui.events()) |*e| {
+                                switch (e.evt) {
+                                    .mouse => |mouse| {
+                                        const action = mouse.action;
+                                        if (dvui.eventMatchSimple(e, scroll.data()) and (action == .wheel_x or action == .wheel_y)) {
+                                            switch (action) {
+                                                .wheel_y => |y| {
+                                                    canvas.addZoom(y / 1000);
+                                                    canvas.redrawExample() catch {};
+                                                },
+                                                else => {},
+                                            }
+                                            e.handled = true;
+                                        }
+                                    },
+                                    else => {},
+                                }
+                            }
+                        }
+                    }
+                    scroll.deinit();
+
+                    dvui.label(@src(), "Canvas", .{}, .{ .gravity_x = 0.5, .gravity_y = 0.0 });
+                }
+                overlay.deinit();
+            }
+            textured.deinit();
+        }
+        right_panel.deinit();
+    }
+    back.deinit();
+
+    ctx.frame_index += 1;
 
     return true;
 }

src/models/Document.zig

@@ -0,0 +1 @@
+// Файл векторного документа

src/models/rasterization_models.zig

@@ -0,0 +1,11 @@
+pub const ImageRect = struct {
+    x: u32,
+    y: u32,
+    w: u32,
+    h: u32,
+};
+
+pub const ImageSize = struct {
+    w: u32,
+    h: u32,
+};

src/render/CpuRenderEngine.zig

@@ -0,0 +1,169 @@
+const std = @import("std");
+const builtin = @import("builtin");
+const dvui = @import("dvui");
+const RenderEngine = @import("RenderEngine.zig").RenderEngine;
+const rast_models = @import("../models/rasterization_models.zig");
+const ImageSize = rast_models.ImageSize;
+const ImageRect = rast_models.ImageRect;
+const Allocator = std.mem.Allocator;
+const Color = dvui.Color;
+
+const CpuRenderEngine = @This();
+const Type = enum {
+    Gradient,
+    Squares,
+};
+
+type: Type,
+_allocator: Allocator,
+gradient_start: Color.PMA = .{ .r = 0, .g = 0, .b = 0, .a = 255 },
+gradient_end: Color.PMA = .{ .r = 255, .g = 255, .b = 255, .a = 255 },
+
+pub fn init(allocator: Allocator, render_type: Type) CpuRenderEngine {
+    return .{
+        ._allocator = allocator,
+        .type = render_type,
+    };
+}
+
+pub fn exampleReset(self: *CpuRenderEngine) void {
+    // Сгенерировать случайные цвета градиента
+    var prng = std.Random.DefaultPrng.init(@intCast(std.time.microTimestamp()));
+    const random = prng.random();
+    self.gradient_start = Color.PMA{ .r = random.int(u8), .g = random.int(u8), .b = random.int(u8), .a = 255 };
+    self.gradient_end = Color.PMA{ .r = random.int(u8), .g = random.int(u8), .b = random.int(u8), .a = 255 };
+}
+
+fn renderGradient(self: CpuRenderEngine, pixels: []Color.PMA, width: u32, height: u32, full_w: u32, full_h: u32, visible_rect: ImageRect) void {
+    var y: u32 = 0;
+    while (y < height) : (y += 1) {
+        var x: u32 = 0;
+        while (x < width) : (x += 1) {
+            const gx: u32 = visible_rect.x + x;
+            const gy: u32 = visible_rect.y + y;
+
+            const denom_x: f32 = if (full_w > 1) @as(f32, @floatFromInt(full_w - 1)) else 1;
+            const denom_y: f32 = if (full_h > 1) @as(f32, @floatFromInt(full_h - 1)) else 1;
+            const fx: f32 = @as(f32, @floatFromInt(gx)) / denom_x;
+            const fy: f32 = @as(f32, @floatFromInt(gy)) / denom_y;
+            const factor: f32 = std.math.clamp((fx + fy) / 2, 0, 1);
+
+            const r_f: f32 = @as(f32, @floatFromInt(self.gradient_start.r)) + factor * (@as(f32, @floatFromInt(self.gradient_end.r)) - @as(f32, @floatFromInt(self.gradient_start.r)));
+            const g_f: f32 = @as(f32, @floatFromInt(self.gradient_start.g)) + factor * (@as(f32, @floatFromInt(self.gradient_end.g)) - @as(f32, @floatFromInt(self.gradient_start.g)));
+            const b_f: f32 = @as(f32, @floatFromInt(self.gradient_start.b)) + factor * (@as(f32, @floatFromInt(self.gradient_end.b)) - @as(f32, @floatFromInt(self.gradient_start.b)));
+
+            const r: u8 = @intFromFloat(std.math.clamp(r_f, 0, 255));
+            const g: u8 = @intFromFloat(std.math.clamp(g_f, 0, 255));
+            const b: u8 = @intFromFloat(std.math.clamp(b_f, 0, 255));
+            pixels[y * width + x] = .{ .r = r, .g = g, .b = b, .a = 255 };
+        }
+    }
+}
+
+fn renderSquares(self: CpuRenderEngine, pixels: []Color.PMA, canvas_size: ImageSize, visible_rect: ImageRect) void {
+    _ = self;
+
+    const squares_num = 5;
+    var thikness: u32 = @intFromFloat(@as(f32, @floatFromInt(canvas_size.w + canvas_size.h)) / 2 * 0.03);
+    if (thikness == 0) thikness = 1;
+
+    const squares_sum_w = canvas_size.w - thikness * (squares_num + 1);
+    const base_w = squares_sum_w / squares_num;
+    const extra_w = squares_sum_w % squares_num;
+    const squares_sum_h = canvas_size.h - thikness * (squares_num + 1);
+    const base_h = squares_sum_h / squares_num;
+    const extra_h = squares_sum_h % squares_num;
+
+    var x_pos: [6]u32 = undefined;
+    x_pos[0] = 0;
+    for (1..squares_num + 1) |i| {
+        const w = base_w + if (i - 1 < extra_w) @as(u32, 1) else 0;
+        x_pos[i] = x_pos[i - 1] + thikness + w;
+    }
+
+    var y_pos: [6]u32 = undefined;
+    y_pos[0] = 0;
+    for (1..squares_num + 1) |i| {
+        const h = base_h + if (i - 1 < extra_h) @as(u32, 1) else 0;
+        y_pos[i] = y_pos[i - 1] + thikness + h;
+    }
+
+    var y: u32 = 0;
+    while (y < visible_rect.h) : (y += 1) {
+        const canvas_y = y + visible_rect.y;
+        if (canvas_y >= canvas_size.h) continue;
+        var x: u32 = 0;
+        while (x < visible_rect.w) : (x += 1) {
+            const canvas_x = x + visible_rect.x;
+            if (canvas_x >= canvas_size.w) continue;
+
+            // Check if in vertical line
+            var in_vertical_line = false;
+            for (x_pos) |pos| {
+                if (canvas_x >= pos and canvas_x < pos + thikness) {
+                    in_vertical_line = true;
+                    break;
+                }
+            }
+
+            // Check if in horizontal line
+            var in_horizontal_line = false;
+            for (y_pos) |pos| {
+                if (canvas_y >= pos and canvas_y < pos + thikness) {
+                    in_horizontal_line = true;
+                    break;
+                }
+            }
+
+            if (in_vertical_line or in_horizontal_line) {
+                pixels[y * visible_rect.w + x] = .{ .r = 255, .g = 0, .b = 0, .a = 255 };
+            } else {
+                // Find square
+                var square_x: u32 = 0;
+                for (0..squares_num) |i| {
+                    if (canvas_x >= x_pos[i] + thikness and canvas_x < x_pos[i + 1]) {
+                        square_x = @intCast(i);
+                        break;
+                    }
+                }
+                var square_y: u32 = 0;
+                for (0..squares_num) |i| {
+                    if (canvas_y >= y_pos[i] + thikness and canvas_y < y_pos[i + 1]) {
+                        square_y = @intCast(i);
+                        break;
+                    }
+                }
+                if (square_x % 2 == square_y % 2) {
+                    pixels[y * visible_rect.w + x] = .{ .r = 255, .g = 255, .b = 255, .a = 255 };
+                } else {
+                    pixels[y * visible_rect.w + x] = .{ .r = 0, .g = 0, .b = 0, .a = 255 };
+                }
+            }
+        }
+    }
+}
+
+pub fn example(self: CpuRenderEngine, canvas_size: ImageSize, visible_rect: ImageRect) !?dvui.Texture {
+    const full_w = canvas_size.w;
+    const full_h = canvas_size.h;
+
+    const width = visible_rect.w;
+    const height = visible_rect.h;
+
+    // Выделить буфер пиксельных данных
+    const pixels = try self._allocator.alloc(Color.PMA, @as(usize, width) * height);
+    defer self._allocator.free(pixels);
+
+    // std.debug.print("w={any}, fw={any};\th={any}, fh={any}\n", .{ width, full_w, height, full_h });
+
+    switch (self.type) {
+        .Gradient => self.renderGradient(pixels, width, height, full_w, full_h, visible_rect),
+        .Squares => self.renderSquares(pixels, canvas_size, visible_rect),
+    }
+
+    return try dvui.textureCreate(pixels, width, height, .nearest);
+}
+
+pub fn renderEngine(self: *CpuRenderEngine) RenderEngine {
+    return .{ .cpu = self };
+}

src/render/RenderEngine.zig

@@ -0,0 +1,20 @@
+// Интерфейс для рендеринга документа
+const dvui = @import("dvui");
+const CpuRenderEngine = @import("CpuRenderEngine.zig");
+const rast_models = @import("../models/rasterization_models.zig");
+
+pub const RenderEngine = union(enum) {
+    cpu: *CpuRenderEngine,
+
+    pub fn exampleReset(self: RenderEngine) void {
+        switch (self) {
+            .cpu => |cpu_r| cpu_r.exampleReset(),
+        }
+    }
+
+    pub fn example(self: RenderEngine, canvas_size: rast_models.ImageSize, visible_rect: rast_models.ImageRect) !?dvui.Texture {
+        return switch (self) {
+            .cpu => |cpu_r| cpu_r.example(canvas_size, visible_rect),
+        };
+    }
+};

src/tests.zig

@@ -0,0 +1,6 @@
+// Test root for `zig build test`.
+// Import modules here to ensure their `test` blocks are discovered.
+
+test "module test discovery" {
+    _ = @import("render/CpuRenderEngine.zig");
+}

src/ui/dvui_ext.zig

@@ -0,0 +1,8 @@
+// Расширения для dvui
+const std = @import("std");
+const dvui = @import("dvui");
+const TexturedBox = @import("./types/TexturedBox.zig");
+
+pub fn texturedBox(rs: dvui.RectScale, corner_radius: dvui.Rect) TexturedBox {
+    return TexturedBox.init(rs, corner_radius);
+}

src/ui/types/TexturedBox.zig

@@ -0,0 +1,38 @@
+// Отрисовка дочернего контента как текстуры с параметрами скругления
+const std = @import("std");
+const dvui = @import("dvui");
+const TexturedBox = @This();
+
+parent: dvui.Widget,
+rs: dvui.RectScale,
+pic: ?dvui.Picture,
+corner_radius: dvui.Rect,
+
+pub fn init(rs: dvui.RectScale, corner_radius: dvui.Rect) TexturedBox {
+    const parent = dvui.parentGet();
+    const pic = dvui.Picture.start(rs.r);
+    return .{
+        .parent = parent,
+        .corner_radius = corner_radius,
+        .rs = rs,
+        .pic = pic,
+    };
+}
+
+pub fn deinit(self: *TexturedBox) void {
+    if (self.pic) |*picture| {
+        picture.stop();
+
+        const tex = dvui.textureFromTarget(picture.texture) catch null;
+        if (tex) |t| {
+            dvui.Texture.destroyLater(t);
+            // self.rs.r.y -= 2;
+            // self.rs.r.x -= 2;
+            // self.rs.r.h += 2;
+            // self.rs.r.w += 2;
+            dvui.renderTexture(t, self.rs, .{
+                .corner_radius = self.corner_radius,
+            }) catch {};
+        }
+    }
+}