Start document model tests

src/document/document.h

@@ -0,0 +1,51 @@
+#pragma once
+
+#include "foundation/result.h"
+#include "paint/blend.h"
+
+#include <cstdint>
+#include <span>
+#include <string>
+#include <string_view>
+#include <vector>
+
+namespace pp::document {
+
+constexpr std::uint32_t max_canvas_dimension = 131072;
+constexpr std::uint32_t max_layer_count = 1024;
+
+struct DocumentConfig {
+    std::uint32_t width = 0;
+    std::uint32_t height = 0;
+    std::uint32_t layer_count = 1;
+};
+
+struct Layer {
+    std::string name;
+    bool visible = true;
+    float opacity = 1.0F;
+    pp::paint::BlendMode blend_mode = pp::paint::BlendMode::normal;
+};
+
+class CanvasDocument {
+public:
+    [[nodiscard]] static pp::foundation::Result<CanvasDocument> create(DocumentConfig config);
+
+    [[nodiscard]] std::uint32_t width() const noexcept;
+    [[nodiscard]] std::uint32_t height() const noexcept;
+    [[nodiscard]] std::size_t active_layer_index() const noexcept;
+    [[nodiscard]] std::span<const Layer> layers() const noexcept;
+
+    [[nodiscard]] pp::foundation::Result<std::size_t> add_layer(std::string_view name);
+    [[nodiscard]] pp::foundation::Status remove_layer(std::size_t index);
+    [[nodiscard]] pp::foundation::Status move_layer(std::size_t from, std::size_t to);
+    [[nodiscard]] pp::foundation::Status set_active_layer(std::size_t index) noexcept;
+
+private:
+    std::uint32_t width_ = 0;
+    std::uint32_t height_ = 0;
+    std::size_t active_layer_index_ = 0;
+    std::vector<Layer> layers_;
+};
+
+}