CAPI_Bitmap.h

Overview

A thread-safe container for pixel data.

#include <Ultralight/CAPI/CAPI_Bitmap.h>

The bitmap class is used to store pixel data in a variety of formats. It intelligently manages the lifetime of the pixel buffer and provides thread-safe access to the pixel data.

Accessing Pixel Data

To access the pixel data, you must first lock the pixels using ulBitmapLockPixels(). This will return a pointer to the pixel buffer. An example follows:

void* pixels = ulBitmapLockPixels(bitmap);
if (pixels) {
  // Zero out the pixel buffer
  memset(pixels, 0, ulBitmapGetSize(bitmap));
}
 
// Unlock the pixels when you're done.
ulBitmapUnlockPixels(bitmap);

Functions
ULBitmap	ulCreateEmptyBitmap ()
	Create empty bitmap.
ULBitmap	ulCreateBitmap (unsigned int width, unsigned int height, ULBitmapFormat format)
	Create bitmap with certain dimensions and pixel format.
ULBitmap	ulCreateBitmapFromPixels (unsigned int width, unsigned int height, ULBitmapFormat format, unsigned int row_bytes, const void *pixels, size_t size, bool should_copy)
	Create bitmap from existing pixel buffer.
ULBitmap	ulCreateBitmapFromCopy (ULBitmap existing_bitmap)
	Create bitmap from copy.
void	ulDestroyBitmap (ULBitmap bitmap)
	Destroy a bitmap (you should only destroy Bitmaps you have explicitly created via one of the creation functions above.
unsigned int	ulBitmapGetWidth (ULBitmap bitmap)
	Get the width in pixels.
unsigned int	ulBitmapGetHeight (ULBitmap bitmap)
	Get the height in pixels.
ULBitmapFormat	ulBitmapGetFormat (ULBitmap bitmap)
	Get the pixel format.
unsigned int	ulBitmapGetBpp (ULBitmap bitmap)
	Get the bytes per pixel.
unsigned int	ulBitmapGetRowBytes (ULBitmap bitmap)
	Get the number of bytes per row.
size_t	ulBitmapGetSize (ULBitmap bitmap)
	Get the size in bytes of the underlying pixel buffer.
bool	ulBitmapOwnsPixels (ULBitmap bitmap)
	Whether or not this bitmap owns its own pixel buffer.
void *	ulBitmapLockPixels (ULBitmap bitmap)
	Lock pixels for reading/writing, returns pointer to pixel buffer.
void	ulBitmapUnlockPixels (ULBitmap bitmap)
	Unlock pixels after locking.
void *	ulBitmapRawPixels (ULBitmap bitmap)
	Get raw pixel buffer– you should only call this if Bitmap is already locked.
bool	ulBitmapIsEmpty (ULBitmap bitmap)
	Whether or not this bitmap is empty.
void	ulBitmapErase (ULBitmap bitmap)
	Reset bitmap pixels to 0.
bool	ulBitmapWritePNG (ULBitmap bitmap, const char *path)
	Write bitmap to a PNG on disk.
void	ulBitmapSwapRedBlueChannels (ULBitmap bitmap)
	This converts a BGRA bitmap to RGBA bitmap and vice-versa by swapping the red and blue channels.

Function Documentation

ulBitmapErase()

void ulBitmapErase

(

ULBitmap

bitmap

)

Reset bitmap pixels to 0.

ulBitmapGetBpp()

unsigned int ulBitmapGetBpp

(

ULBitmap

bitmap

)

Get the bytes per pixel.

ulBitmapGetFormat()

ULBitmapFormat ulBitmapGetFormat

(

ULBitmap

bitmap

)

Get the pixel format.

ulBitmapGetHeight()

unsigned int ulBitmapGetHeight

(

ULBitmap

bitmap

)

Get the height in pixels.

ulBitmapGetRowBytes()

unsigned int ulBitmapGetRowBytes

(

ULBitmap

bitmap

)

Get the number of bytes per row.

ulBitmapGetSize()

size_t ulBitmapGetSize

(

ULBitmap

bitmap

)

Get the size in bytes of the underlying pixel buffer.

ulBitmapGetWidth()

unsigned int ulBitmapGetWidth

(

ULBitmap

bitmap

)

Get the width in pixels.

ulBitmapIsEmpty()

bool ulBitmapIsEmpty

(

ULBitmap

bitmap

)

Whether or not this bitmap is empty.

ulBitmapLockPixels()

void * ulBitmapLockPixels

(

ULBitmap

bitmap

)

Lock pixels for reading/writing, returns pointer to pixel buffer.

ulBitmapOwnsPixels()

bool ulBitmapOwnsPixels

(

ULBitmap

bitmap

)

Whether or not this bitmap owns its own pixel buffer.

ulBitmapRawPixels()

void * ulBitmapRawPixels

(

ULBitmap

bitmap

)

Get raw pixel buffer– you should only call this if Bitmap is already locked.

ulBitmapSwapRedBlueChannels()

void ulBitmapSwapRedBlueChannels

(

ULBitmap

bitmap

)

This converts a BGRA bitmap to RGBA bitmap and vice-versa by swapping the red and blue channels.

ulBitmapUnlockPixels()

void ulBitmapUnlockPixels

(

ULBitmap

bitmap

)

Unlock pixels after locking.

ulBitmapWritePNG()

bool ulBitmapWritePNG	(	ULBitmap	bitmap,
		const char *	path )

Write bitmap to a PNG on disk.

ulCreateBitmap()

ULBitmap ulCreateBitmap	(	unsigned int	width,
		unsigned int	height,
		ULBitmapFormat	format )

Create bitmap with certain dimensions and pixel format.

ulCreateBitmapFromCopy()

ULBitmap ulCreateBitmapFromCopy

(

ULBitmap

existing_bitmap

)

Create bitmap from copy.

ulCreateBitmapFromPixels()

ULBitmap ulCreateBitmapFromPixels	(	unsigned int	width,
		unsigned int	height,
		ULBitmapFormat	format,
		unsigned int	row_bytes,
		const void *	pixels,
		size_t	size,
		bool	should_copy )

Create bitmap from existing pixel buffer.

See also

Bitmap for help using this function.

ulCreateEmptyBitmap()

ULBitmap ulCreateEmptyBitmap

(

)

Create empty bitmap.

ulDestroyBitmap()

void ulDestroyBitmap

(

ULBitmap

bitmap

)

Destroy a bitmap (you should only destroy Bitmaps you have explicitly created via one of the creation functions above.

Go to the source code of this file.