Merge pull request #1940 from tannewt/dirty_area

 Add partial display update support.

1 files changed, 29 insertions, 4 deletions

diff --git a/shared-module/displayio/TileGrid.h b/shared-module/displayio/TileGrid.h
index 6157dfbe8..4d97eccc2 100644
--- a/shared-module/displayio/TileGrid.h
+++ b/shared-module/displayio/TileGrid.h
@@ -37,7 +37,10 @@ typedef struct {
     mp_obj_base_t base;
     mp_obj_t bitmap;
     mp_obj_t pixel_shader;
-    displayio_area_t area;
+    int16_t x;
+    int16_t y;
+    uint16_t pixel_width;
+    uint16_t pixel_height;
     uint16_t bitmap_width_in_tiles;
     uint16_t width_in_tiles;
     uint16_t height_in_tiles;
@@ -46,12 +49,34 @@ typedef struct {
     uint16_t top_left_x;
     uint16_t top_left_y;
     uint8_t* tiles;
-    bool needs_refresh;
+    const displayio_buffer_transform_t* absolute_transform;
+    displayio_area_t dirty_area; // Stored as a relative area until the refresh area is fetched.
+    displayio_area_t previous_area; // Stored as an absolute area.
+    displayio_area_t current_area; // Stored as an absolute area so it applies across frames.
+    bool partial_change;
+    bool full_change;
+    bool first_draw;
+    bool moved;
     bool inline_tiles;
+    bool in_group;
+    bool flip_x;
+    bool flip_y;
+    bool transpose_xy;
 } displayio_tilegrid_t;
 
-bool displayio_tilegrid_get_area(displayio_tilegrid_t *self, displayio_buffer_transform_t* transform, displayio_area_t* area, uint32_t* mask, uint32_t *buffer);
-bool displayio_tilegrid_needs_refresh(displayio_tilegrid_t *self);
+// Updating the screen is a three stage process.
+
+// The first stage is used to determine i
+displayio_area_t* displayio_tilegrid_get_refresh_areas(displayio_tilegrid_t *self, displayio_area_t* tail);
+
+// Area is always in absolute screen coordinates. Update transform is used to inform TileGrids how
+// they relate to it.
+bool displayio_tilegrid_fill_area(displayio_tilegrid_t *self, const displayio_area_t* area, uint32_t* mask, uint32_t *buffer);
+void displayio_tilegrid_update_transform(displayio_tilegrid_t *group, const displayio_buffer_transform_t* parent_transform);
+
+// Fills in area with the maximum bounds of all related pixels in the last rendered frame. Returns
+// false if the tilegrid wasn't rendered in the last frame.
+bool displayio_tilegrid_get_previous_area(displayio_tilegrid_t *self, displayio_area_t* area);
 void displayio_tilegrid_finish_refresh(displayio_tilegrid_t *self);
 
 #endif // MICROPY_INCLUDED_SHARED_MODULE_DISPLAYIO_TILEGRID_H