DirtyGrid

Class

Source: DirtyGrid.h

Description

Two-buffer dirty cell grid (8×8 px cells) for selective framebuffer clears.

Bit-packed storage: one bit per cell. curr accumulates marks for the current frame; swapAndClear() moves that state into prev for the next frame's cleanup pass.

Methods

bool init(int screenW, int screenH)

Description:

Initializes the dirty grid dimensions based on screen size.

Parameters:

• screenW: Width of the screen in pixels.
• screenH: Height of the screen in pixels.

Returns: true if initialization succeeded, false on allocation failure.

void markCell(uint8_t cx, uint8_t cy)

Description:

Marks a specific cell as dirty in the current frame.

Parameters:

• cx: Cell X coordinate.
• cy: Cell Y coordinate.

void markRect(int x, int y, int w, int h)

Description:

Marks cells intersected by a rectangle as dirty.

Parameters:

• x: Top-left X coordinate in pixels.
• y: Top-left Y coordinate in pixels.
• w: Width of the rectangle in pixels.
• h: Height of the rectangle in pixels.

bool isPrevDirty(uint8_t cx, uint8_t cy) const

Description:

Checks if a cell was marked dirty in the previous frame.

Parameters:

• cx: Cell X coordinate.
• cy: Cell Y coordinate.

Returns: true if the cell was dirty in the previous frame, false otherwise.

bool intersectsPrevDirty(int x, int y, int w, int h) const

Description:

Checks whether any 8×8 cell covered by a pixel rectangle was marked dirty in the previous frame.

Parameters:

• x: Top-left X coordinate in pixels.
• y: Top-left Y coordinate in pixels.
• w: Width of the rectangle in pixels.
• h: Height of the rectangle in pixels.

Returns: true if any covered cell was dirty in the previous frame, false otherwise.

void swapAndClear()

Description:

Swaps the current and previous buffers, clearing the new current buffer.

void markAll()

Description:

Marks all cells as dirty in the current frame.

bool isFullDirty() const

Description:

Checks if the entire grid is marked as fully dirty.

Returns: true if the grid is fully dirty, false otherwise.

void setFullDirty(bool v)

Description:

Sets the full dirty state of the grid.

Parameters:

• v: The full dirty state to set.

uint8_t getCols() const

Description:

Gets the number of columns in the grid.

Returns: The number of columns.

uint8_t getRows() const

Description:

Gets the number of rows in the grid.

Returns: The number of rows.

uint32_t countPrevMarkedCells() const

Description:

Gets the number of cells marked in the previous frame.

Returns: The number of cells marked in the previous frame.

uint32_t countCurrMarkedCells() const

Description:

Gets the number of cells marked in the current frame.

Returns: The number of cells marked in the current frame.

uint32_t totalCellCount() const

Description:

Gets the total number of cells in the grid.

Returns: The total number of cells in the grid.

bool isCurrMarked(uint8_t cx, uint8_t cy) const

Description:

True when the curr buffer has this cell marked for the current frame.

Parameters:

• cx: Cell X coordinate.
• cy: Cell Y coordinate.

Returns: True when the curr buffer has this cell marked for the current frame, false otherwise.

void clearFramebuffer8FromPrev(uint8_t* fb, int framebufferWidth, int framebufferHeight, uint8_t fillByte) const

Parameters:

• framebufferWidth: Row stride in bytes (typically logical width).

void restoreFramebuffer8FromPrev(uint8_t* fb, const uint8_t* snapshot, int framebufferWidth, int framebufferHeight) const

Parameters:

• framebufferWidth: Row stride in bytes (typically logical width).