canvas_types.h

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#ifndef YAZE_APP_GUI_CANVAS_CANVAS_TYPES_H
#define YAZE_APP_GUI_CANVAS_CANVAS_TYPES_H
 
// POD and option structs for the canvas subsystem.
 
#include <cstdint>
#include <optional>
 
#include "imgui/imgui.h"
 
namespace yaze {
namespace gui {
 
enum class CanvasType { kTile, kBlock, kMap };
enum class CanvasMode { kPaint, kSelect };
enum class CanvasGridSize { k8x8, k16x16, k32x32, k64x64 };
 
// Describes the role this canvas plays: what it's for, distinct from
// CanvasMode which describes the input behavior the user is currently
// performing. A canvas can have CanvasMode::kSelect while being either a
// kSelectionSource (picker) or a kEditableScratchpad (rect-select-then-edit).
//
// Editors set this once at Init/Begin time. Canvas reads it for cursor and
// hover-hint defaults; it does not gate operations.
enum class CanvasRole : uint8_t {
  kPreviewOnly,         // Read-only display (gfx-group sheet thumbnail).
  kSelectionSource,     // Read-only tile/region picker source.
  kEditableScratchpad,  // User-editable target (default).
  kCompositeOutput,     // Post-render composite output.
};
 
// True when the canvas's underlying bitmap is owned by the editor and may be
// mutated through it. False for kPreviewOnly/kSelectionSource canvases whose
// bitmap is a shared view (gfx-group sheets, sprite atlas thumbnails) where
// destructive operations like Reformat/SetPalette would corrupt every other
// view of the same data. The context menu uses this to suppress
// "Pixel Format" and "Edit Palette" entries on read-only canvases.
constexpr bool RoleAllowsBitmapMutation(CanvasRole role) {
  return role == CanvasRole::kEditableScratchpad ||
         role == CanvasRole::kCompositeOutput;
}
 
struct CanvasRuntime {
  ImDrawList* draw_list = nullptr;
  ImVec2 canvas_p0 = ImVec2(0, 0);
  ImVec2 canvas_sz = ImVec2(0, 0);
  ImVec2 scrolling = ImVec2(0, 0);
  ImVec2 mouse_pos_local = ImVec2(0, 0);
  bool hovered = false;
  float grid_step = 16.0f;
  float scale = 1.0f;
  ImVec2 content_size = ImVec2(0, 0);
};
 
struct CanvasFrameOptions {
  ImVec2 canvas_size = ImVec2(0, 0);
  // Optional fixed viewport in screen pixels. The content still uses
  // canvas_size/global_scale, but zooming cannot enlarge the host item.
  std::optional<ImVec2> viewport_size;
  bool draw_context_menu = true;
  bool draw_grid = true;
  std::optional<float> grid_step;
  bool draw_overlay = true;
  bool render_popups = true;
  bool use_child_window = false;
  bool show_scrollbar = false;
};
 
struct BitmapPreviewOptions {
  ImVec2 canvas_size = ImVec2(0, 0);
  ImVec2 dest_pos = ImVec2(0, 0);
  ImVec2 dest_size = ImVec2(0, 0);
  ImVec2 src_pos = ImVec2(0, 0);
  ImVec2 src_size = ImVec2(0, 0);
  float scale = 1.0f;
  int alpha = 255;
  bool draw_context_menu = false;
  bool draw_grid = true;
  std::optional<float> grid_step;
  bool draw_overlay = true;
  bool render_popups = true;
  bool ensure_texture = false;
  int selector_tile_size = 0;
  int selector_tile_size_y = 0;
};
 
struct TileHit {
  int tile_index = -1;
  ImVec2 tile_origin = ImVec2(0, 0);
  ImVec2 tile_size = ImVec2(0, 0);
};
 
struct BitmapDrawOpts {
  ImVec2 dest_pos = ImVec2(0, 0);
  ImVec2 dest_size = ImVec2(0, 0);
  ImVec2 src_pos = ImVec2(0, 0);
  ImVec2 src_size = ImVec2(0, 0);
  float scale = 1.0f;
  int alpha = 255;
  bool ensure_texture = true;
};
 
struct SelectorPanelOpts {
  ImVec2 canvas_size = ImVec2(0, 0);
  float grid_step = 16.0f;
  bool show_grid = true;
  bool show_overlay = true;
  bool render_popups = true;
  bool ensure_texture = true;
  int tile_selector_size = 0;
  int tile_selector_size_y = 0;
};
 
struct PreviewPanelOpts {
  ImVec2 canvas_size = ImVec2(0, 0);
  ImVec2 dest_pos = ImVec2(0, 0);
  ImVec2 dest_size = ImVec2(0, 0);
  float grid_step = 0.0f;
  bool render_popups = false;
  bool ensure_texture = true;
};
 
struct ZoomToFitResult {
  float scale = 1.0f;
  ImVec2 scroll = ImVec2(0, 0);
};
 
}  // namespace gui
}  // namespace yaze
 
#endif  // YAZE_APP_GUI_CANVAS_CANVAS_TYPES_H