Manages multiple textures packed into a single large texture for performance. More...

#include <texture_atlas.h>

Collaboration diagram for yaze::gfx::TextureAtlas:

[legend]

Classes
struct	AtlasRegion
	Region within the atlas texture. More...

struct	AtlasStats
	Get atlas utilization statistics. More...

Public Member Functions
	TextureAtlas (int width=2048, int height=2048)
	Construct texture atlas with specified dimensions.

AtlasRegion *	AllocateRegion (int source_id, int width, int height)
	Allocate a region in the atlas for a source texture.

absl::Status	PackBitmap (const Bitmap &src, const AtlasRegion &region)
	Pack a bitmap into an allocated region.

absl::Status	DrawRegion (int source_id, int dest_x, int dest_y)
	Draw a region from the atlas to screen coordinates.

void	FreeRegion (int source_id)
	Free a region and mark it as available.

void	Clear ()
	Clear all regions and reset atlas.

Bitmap &	GetAtlasBitmap ()
	Get the atlas bitmap (contains all packed textures)

const Bitmap &	GetAtlasBitmap () const

const AtlasRegion *	GetRegion (int source_id) const
	Get region for a specific source.

int	width () const
	Get atlas dimensions.

int	height () const

AtlasStats	GetStats () const

Private Member Functions
bool	TryPackRect (int width, int height, int &out_x, int &out_y)

Private Attributes
int	width_

int	height_

Bitmap	atlas_bitmap_

int	next_x_ = 0

int	next_y_ = 0

int	row_height_ = 0

std::map< int, AtlasRegion >	regions_

Detailed Description

Manages multiple textures packed into a single large texture for performance.

Future-proof infrastructure for combining multiple room textures into one atlas. This reduces GPU state changes and improves rendering performance when many rooms are open.

Benefits:

Fewer texture binds per frame
Better memory locality
Reduced VRAM fragmentation
Easier batch rendering

Usage (Future): TextureAtlas atlas(2048, 2048); auto region = atlas.AllocateRegion(room_id, 512, 512); atlas.PackBitmap(room.bg1_buffer().bitmap(), *region); atlas.DrawRegion(room_id, x, y);

Definition at line 33 of file texture_atlas.h.

Constructor & Destructor Documentation

◆ TextureAtlas()

yaze::gfx::TextureAtlas::TextureAtlas	(	int	width = `2048`,
		int	height = `2048`
	)

explicit

Construct texture atlas with specified dimensions.

Parameters

width	Atlas width in pixels (typically 2048 or 4096)
height	Atlas height in pixels (typically 2048 or 4096)

Definition at line 8 of file texture_atlas.cc.

References atlas_bitmap_, height(), LOG_DEBUG, and width().

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Member Function Documentation

◆ AllocateRegion()

TextureAtlas::AtlasRegion * yaze::gfx::TextureAtlas::AllocateRegion	(	int	source_id,
		int	width,
		int	height
	)

Allocate a region in the atlas for a source texture.

Parameters

source_id	Identifier for the source (e.g., room_id)
width	Required width in pixels
height	Required height in pixels

Returns: Pointer to allocated region, or nullptr if no space

Uses simple rect packing algorithm. Future: implement more efficient packing.

Todo:: Implement more efficient rect packing (shelf, guillotine, etc.)

Definition at line 16 of file texture_atlas.cc.

References yaze::gfx::TextureAtlas::AtlasRegion::height, height(), yaze::gfx::TextureAtlas::AtlasRegion::in_use, LOG_DEBUG, regions_, yaze::gfx::TextureAtlas::AtlasRegion::source_id, TryPackRect(), yaze::gfx::TextureAtlas::AtlasRegion::width, width(), yaze::gfx::TextureAtlas::AtlasRegion::x, and yaze::gfx::TextureAtlas::AtlasRegion::y.

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◆ PackBitmap()

absl::Status yaze::gfx::TextureAtlas::PackBitmap	(	const Bitmap &	src,
		const AtlasRegion &	region
	)

Pack a bitmap into an allocated region.

Parameters

src	Source bitmap to pack
region	Region to pack into (must be pre-allocated)

Returns: Status of packing operation

Copies pixel data from source bitmap into atlas at region coordinates.

Todo:: Implement pixel copying from src to atlas_bitmap_ at region coordinates

Definition at line 43 of file texture_atlas.cc.

References yaze::gfx::Bitmap::height(), yaze::gfx::TextureAtlas::AtlasRegion::height, yaze::gfx::TextureAtlas::AtlasRegion::in_use, yaze::gfx::Bitmap::is_active(), LOG_DEBUG, yaze::gfx::TextureAtlas::AtlasRegion::source_id, yaze::gfx::Bitmap::width(), yaze::gfx::TextureAtlas::AtlasRegion::width, yaze::gfx::TextureAtlas::AtlasRegion::x, and yaze::gfx::TextureAtlas::AtlasRegion::y.

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◆ DrawRegion()

absl::Status yaze::gfx::TextureAtlas::DrawRegion	(	int	source_id,
		int	dest_x,
		int	dest_y
	)

Draw a region from the atlas to screen coordinates.

Parameters

source_id	Source identifier (e.g., room_id)
dest_x	Destination X coordinate
dest_y	Destination Y coordinate

Returns: Status of drawing operation

Future: Integrate with renderer to draw atlas regions.

Todo:: Integrate with renderer to draw atlas region at (dest_x, dest_y)

Definition at line 65 of file texture_atlas.cc.

References regions_.

◆ FreeRegion()

void yaze::gfx::TextureAtlas::FreeRegion ( int source_id )

Free a region and mark it as available.

Parameters

source_id Source identifier to free

Definition at line 77 of file texture_atlas.cc.

References LOG_DEBUG, and regions_.

◆ Clear()

void yaze::gfx::TextureAtlas::Clear ( )

Clear all regions and reset atlas.

Definition at line 85 of file texture_atlas.cc.

References LOG_DEBUG, next_x_, next_y_, regions_, and row_height_.

◆ GetAtlasBitmap() [1/2]

Bitmap & yaze::gfx::TextureAtlas::GetAtlasBitmap ( )

inline

Get the atlas bitmap (contains all packed textures)

Returns: Reference to atlas bitmap

Definition at line 101 of file texture_atlas.h.

References atlas_bitmap_.

◆ GetAtlasBitmap() [2/2]

const Bitmap & yaze::gfx::TextureAtlas::GetAtlasBitmap ( ) const

inline

Definition at line 102 of file texture_atlas.h.

References atlas_bitmap_.

◆ GetRegion()

const TextureAtlas::AtlasRegion * yaze::gfx::TextureAtlas::GetRegion ( int source_id ) const

Get region for a specific source.

Parameters

source_id Source identifier

Returns: Pointer to region, or nullptr if not found

Definition at line 93 of file texture_atlas.cc.

References regions_.

◆ width()

int yaze::gfx::TextureAtlas::width ( ) const

inline

Get atlas dimensions.

Definition at line 114 of file texture_atlas.h.

References width_.

Referenced by AllocateRegion(), TextureAtlas(), and TryPackRect().

◆ height()

int yaze::gfx::TextureAtlas::height ( ) const

inline

Definition at line 115 of file texture_atlas.h.

References height_.

Referenced by AllocateRegion(), TextureAtlas(), and TryPackRect().

◆ GetStats()

TextureAtlas::AtlasStats yaze::gfx::TextureAtlas::GetStats ( ) const

Definition at line 101 of file texture_atlas.cc.

References height_, regions_, yaze::gfx::TextureAtlas::AtlasStats::total_pixels, yaze::gfx::TextureAtlas::AtlasStats::total_regions, yaze::gfx::TextureAtlas::AtlasStats::used_pixels, yaze::gfx::TextureAtlas::AtlasStats::used_regions, yaze::gfx::TextureAtlas::AtlasStats::utilization, and width_.

◆ TryPackRect()

bool yaze::gfx::TextureAtlas::TryPackRect	(	int	width,
		int	height,
		int &	out_x,
		int &	out_y
	)

private

Definition at line 120 of file texture_atlas.cc.

References height(), height_, next_x_, next_y_, row_height_, width(), and width_.

Referenced by AllocateRegion().

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Member Data Documentation

◆ width_

int yaze::gfx::TextureAtlas::width_

private

Definition at line 130 of file texture_atlas.h.

Referenced by GetStats(), TryPackRect(), and width().

◆ height_

int yaze::gfx::TextureAtlas::height_

private

Definition at line 131 of file texture_atlas.h.

Referenced by GetStats(), height(), and TryPackRect().

◆ atlas_bitmap_

Bitmap yaze::gfx::TextureAtlas::atlas_bitmap_

private

Definition at line 132 of file texture_atlas.h.

Referenced by GetAtlasBitmap(), GetAtlasBitmap(), and TextureAtlas().

◆ next_x_

int yaze::gfx::TextureAtlas::next_x_ = 0

private

Definition at line 135 of file texture_atlas.h.

Referenced by Clear(), and TryPackRect().

◆ next_y_

int yaze::gfx::TextureAtlas::next_y_ = 0

private

Definition at line 136 of file texture_atlas.h.

Referenced by Clear(), and TryPackRect().

◆ row_height_

int yaze::gfx::TextureAtlas::row_height_ = 0

private

Definition at line 137 of file texture_atlas.h.

Referenced by Clear(), and TryPackRect().

◆ regions_

std::map<int, AtlasRegion> yaze::gfx::TextureAtlas::regions_

private

Definition at line 140 of file texture_atlas.h.

Referenced by AllocateRegion(), Clear(), DrawRegion(), FreeRegion(), GetRegion(), and GetStats().

The documentation for this class was generated from the following files:

src/app/gfx/texture_atlas.h
src/app/gfx/texture_atlas.cc

	yaze 0.3.2 Link to the Past ROM Editor

Classes

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ TextureAtlas()

Member Function Documentation

◆ AllocateRegion()

◆ PackBitmap()

◆ DrawRegion()

◆ FreeRegion()

◆ Clear()

◆ GetAtlasBitmap() [1/2]

◆ GetAtlasBitmap() [2/2]

◆ GetRegion()

◆ width()

◆ height()

◆ GetStats()

◆ TryPackRect()

Member Data Documentation

◆ width_

◆ height_

◆ atlas_bitmap_

◆ next_x_

◆ next_y_

◆ row_height_

◆ regions_