Bitmap Class Reference
[Graphics]

Inheritance diagram for Bitmap:

List of all members.

Public Types
enum	Transformation {   NoTransformation, Rotate_90, Rotate_180, Rotate_270,   Mirror_X, Mirror_Y, Transformations_Count }
Public Member Functions
	Bitmap ()
virtual StringId	GetType ()=0
virtual	~Bitmap ()
virtual unsigned short *	GetColorData () const
virtual unsigned char *	GetAlphaData () const
virtual int	GetHPitch () const
virtual int	GetVPitch () const
virtual int	GetHOffset () const
virtual int	GetVOffset () const
virtual void	Clear ()
virtual void	Fill (unsigned short color, unsigned char alpha=255)
virtual void	Fill (int x1, int y1, int x2, int y2, unsigned short color, unsigned char alpha=255)
virtual void	FillAlpha (unsigned char alpha)
virtual void	FillAlpha (int x1, int y1, int x2, int y2, unsigned char alpha)
virtual int	GetWidth (Transformation transformation=NoTransformation) const
virtual int	GetHeight (Transformation transformation=NoTransformation) const
virtual unsigned short	GetPixelColor (int x, int y, Transformation transformation=NoTransformation) const
virtual unsigned char	GetPixelAlpha (int x, int y, Transformation transformation=NoTransformation) const
virtual void	SetPixelColor (int x, int y, unsigned short color, Transformation transformation=NoTransformation)
virtual void	SetPixelAlpha (int x, int y, unsigned char alpha, Transformation transformation=NoTransformation)
virtual void	BlendPixel (int x, int y, unsigned short color, unsigned char alpha, Transformation transformation=NoTransformation)
virtual void	Blit (Bitmap &target, int x, int y, unsigned short modulate=0xffff, unsigned char alpha=255, Transformation transformation=NoTransformation) const
virtual void	Blit (int x1, int y1, int x2, int y2, Bitmap &target, int x, int y, unsigned short modulate=0xffff, unsigned char alpha=255, Transformation transformation=NoTransformation) const
virtual void	Copy (Bitmap &target, int x, int y, unsigned short modulate=0xffff, Transformation transformation=NoTransformation) const
virtual void	Copy (int x1, int y1, int x2, int y2, Bitmap &target, int x, int y, unsigned short modulate=0xffff, Transformation transformation=NoTransformation) const
virtual void	Save (Asset &asset) const =0
virtual void	Load (const Asset &asset)=0
virtual void	WriteToAsset (Asset *asset) const =0
virtual void	ReadFromAsset (const Asset *asset)=0
Protected Member Functions
void	TransformCoordinates (int &x, int &y, Transformation transformation) const
bool	Clip (int &sourceX, int &sourceY, int &sourceWidth, int &sourceHeight, int &targetX, int &targetY, int targetWidth, int targetHeight, Transformation transformation) const
Protected Attributes
unsigned short *	color_
	Pixel color data (hPitch*vPitch).
unsigned char *	alpha_
	Pixel alpha data (width*height).
int	width_
	Width of the bitmap.
int	height_
	Height of the bitmap.
int	hPitch_
	Horizontal pitch (dimension) of the bitmap.
int	vPitch_
	Vertical pitch (dimension) of the bitmap.
int	hOffset_
	Horizontal offset from bitmap origin to data.
int	vOffset_
	Vertical offset from bitmap origin to data.

---

Detailed Description

Author:

Mattias Gustavsson

A Bitmap is simply a collection of 16-bit color values with a width and a height. It is typically used as blit target, and is also what you pass on to the Present method of Platform_Screen to display stuff.

Bitmaps can be blitted onto other bitmaps, but this is quite slow as the code is not yet optimized. It is recommended that you use just one bitmap (for your back buffer) and make all your other art of the type Bitmap_RLE8, as this can be blitted onto a Bitmap in the same way, but is much, much faster.

Todo:

Update Clip code to handle offset/pitch. Might be fixed, but needs cleaning up (transforms and such)

Additive blitting

Make TransformCoordinates non-inline

Definition at line 32 of file Bitmap.h.

---

Member Enumeration Documentation

enum Bitmap::Transformation

Sometimes it is useful to rotate or flip bitmaps. The methods specified below all takes a Transformation parameter, which will cause the method to function as if the bitmap was transformed in the manner specified, without actually transforming any pixel data. This means you can blit an image upside down by just passing Mirror_Y as the transformation parameter to the blit method. All the transformation parameters default to untransformed, so just omit the parameter if you don't want to think about transformations...

Enumerator:

NoTransformation	The bitmap is not transformed.
Rotate_90	The bitmap is rotated 90 degrees clockwise.
Rotate_180	The bitmap is rotated 180 degrees.
Rotate_270	The bitmap is rotated 270 degrees clockwise / 90 degrees counter clockwise.
Mirror_X	The bitmap is flipped horizontally.
Mirror_Y	The bitmap is flipped vertically.
Transformations_Count	Number of available transformations, handy if you want to pick a random one.

Definition at line 139 of file Bitmap.h.

---

Constructor & Destructor Documentation

Bitmap::Bitmap

(

)

Definition at line 11 of file Bitmap.cpp.

virtual Bitmap::~Bitmap

(

)

[virtual]

The Bitmap class has an empty, virtual destructor, so that you can delete a pointer of type Bitmap, and still have the destructor of it's subtype called properly.

Definition at line 51 of file Bitmap.h.

---

Member Function Documentation

virtual StringId Bitmap::GetType

(

)

[pure virtual]

The Bitmap class is an abstract interface, and is implemented by a number of different bitmap classes. The GetType method retrieves the name of the actual implementation for the Bitmap instance.

Returns:

A StringId containing the class name of this bitmaps implementation

Implemented in Bitmap_16bit, Bitmap_16bitAlpha, Bitmap_16bitAlphaCrop, Bitmap_Alpha, Bitmap_RLE16, and Bitmap_RLE8.

unsigned short * Bitmap::GetColorData

(

)

const [virtual]

Get the raw data pointer to the bitmap data. This should be used with care, as it can be quite easy to read outside the valid memory area. There might be Bitmap implementations which doesn't have color data, so this method can return 0.

Returns:

A pointer to the pixel data (each pixel is a 16 bit color value, on the form R5G6B5)

Definition at line 26 of file Bitmap.cpp.

unsigned char * Bitmap::GetAlphaData

(

)

const [virtual]

Get the raw data pointer to the bitmaps alpha channel data. This should be used with care, as it can be quite easy to read outside the valid memory area. There might be Bitmap implementations which doesn't have an alpha channel, so this method can return 0.

Returns:

A pointer to the alpha channel data (each pixel is a 8 bit transparency value, 0=Fully transparent, 255=Fully Opaque

Definition at line 34 of file Bitmap.cpp.

int Bitmap::GetHPitch

(

)

const [virtual]

Definition at line 43 of file Bitmap.cpp.

int Bitmap::GetVPitch

(

)

const [virtual]

Definition at line 51 of file Bitmap.cpp.

int Bitmap::GetHOffset

(

)

const [virtual]

Definition at line 59 of file Bitmap.cpp.

int Bitmap::GetVOffset

(

)

const [virtual]

Definition at line 67 of file Bitmap.cpp.

void Bitmap::Clear

(

)

[virtual]

Sets every pixel of the bitmap to black (0). Internally this just uses a memset for speed. If you want to clear to any other color, you need to use the Fill method, which is slightly slower. If the bitmap has an alpha channel, it will be cleared too.

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 75 of file Bitmap.cpp.

void Bitmap::Fill	(	unsigned short	color,
		unsigned char	alpha = 255
	)			[virtual]

Fills the entire bitmap with the specified color. If an alpha value is specified, the fill will be semi-transparent, and what was already in the bitmap will show through. If the bitmap has an alpha channel, it won't be affected by Fill.

Parameters:

	color	16 bit color (R5G6B5) to fill the specified area with
	alpha	Level of transparency for the fill. 0=Fully transparent, 255=Fully Opaque

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 180 of file Bitmap.cpp.

void Bitmap::Fill	(	int	x1,
		int	y1,
		int	x2,
		int	y2,
		unsigned short	color,
		unsigned char	alpha = 255
	)			[virtual]

Fills the specified area of the bitmap with the specified color. If an alpha value is specified, the filled area will be semi-transparent, and what was already in the bitmap will show through. Note that the filled area will include the x2 and y2 pixels as well (it won't leave the last pixel blank as for instance DirectX dies).

If the specified area is outside of the bitmap, it will be clipped to the extents of the bitmap. If the bitmap has an alpha channel, it won't be affected by Fill.

Parameters:

	x1	X-coordinate of the top-left corner of the area to be filled
	y1	Y-coordinate of the top-left corner of the area to be filled
	x2	X-coordinate of the bottom-right corner of the area to be filled
	y2	Y-coordinate of the bottom-right corner of the area to be filled
	color	16 bit color (R5G6B5) to fill the specified area with
	alpha	Level of transparency for the fill. 0=Fully transparent, 255=Fully Opaque

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 91 of file Bitmap.cpp.

void Bitmap::FillAlpha

(

unsigned char

alpha

)

[virtual]

Parameters:

alpha

Level of transparency for the fill. 0=Fully transparent, 255=Fully Opaque

Definition at line 288 of file Bitmap.cpp.

void Bitmap::FillAlpha	(	int	x1,
		int	y1,
		int	x2,
		int	y2,
		unsigned char	alpha
	)			[virtual]

Parameters:

	x1	X-coordinate of the top-left corner of the area to be filled
	y1	Y-coordinate of the top-left corner of the area to be filled
	x2	X-coordinate of the bottom-right corner of the area to be filled
	y2	Y-coordinate of the bottom-right corner of the area to be filled
	alpha	Level of transparency for the fill. 0=Fully transparent, 255=Fully Opaque

Definition at line 235 of file Bitmap.cpp.

int Bitmap::GetWidth

(

Transformation

transformation = NoTransformation

)

const [virtual]

Gets the width of the bitmap

Returns:

The width of the bitmap in pixels

Parameters:

transformation

Specifies the desired transformation to use for this operation

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 311 of file Bitmap.cpp.

int Bitmap::GetHeight

(

Transformation

transformation = NoTransformation

)

const [virtual]

Gets the height of the bitmap

Returns:

The height of the bitmap in pixels

Parameters:

transformation

Specifies the desired transformation to use for this operation

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 336 of file Bitmap.cpp.

unsigned short Bitmap::GetPixelColor	(	int	x,
		int	y,
		Transformation	transformation = NoTransformation
	)			const [virtual]

Gets the 16 bit (R5G6B5) pixel at the specified coordinate of the bitmap This version of GetPixel will take an Transformation parameters, so you can get pixels as if the bitmap was transformed.

Returns:

The pixel at the specified coordinate

Parameters:

	x	X-coordinate of pixel to get
	y	Y-coordinate of pixel to get
	transformation	Specifies the desired transformation to use for this operation

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 361 of file Bitmap.cpp.

unsigned char Bitmap::GetPixelAlpha	(	int	x,
		int	y,
		Transformation	transformation = NoTransformation
	)			const [virtual]

Parameters:

	x	X-coordinate of pixel to get
	y	Y-coordinate of pixel to get
	transformation	Specifies the desired transformation to use for this operation

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 379 of file Bitmap.cpp.

void Bitmap::SetPixelColor	(	int	x,
		int	y,
		unsigned short	color,
		Transformation	transformation = NoTransformation
	)			[virtual]

Changes the pixel at the specified coordinate of the bitmap. This version of SetPixel will take an Transformation parameters, so you can set pixels as if the bitmap was transformed.

Parameters:

	x	X-coordinate of pixel to set
	y	Y-coordinate of pixel to set
	color	16 bit color (R5G6B5) to set the specified coordinate to
	transformation	Specifies the desired transformation to use for this operation

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 398 of file Bitmap.cpp.

void Bitmap::SetPixelAlpha	(	int	x,
		int	y,
		unsigned char	alpha,
		Transformation	transformation = NoTransformation
	)			[virtual]

Parameters:

	x	X-coordinate of pixel to set
	y	Y-coordinate of pixel to set
	transformation	Specifies the desired transformation to use for this operation

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 415 of file Bitmap.cpp.

void Bitmap::BlendPixel	(	int	x,
		int	y,
		unsigned short	color,
		unsigned char	alpha,
		Transformation	transformation = NoTransformation
	)			[virtual]

Blends the pixel at the specified coordinate with the specified color, using the specified alpha value as a blend factor. This version of BlenPixel will take an Transformation parameters, so you can blend pixels as if the bitmap was transformed.

Parameters:

	x	X-coordinate of pixel to change
	y	Y-coordinate of pixel to change
	color	16 bit color (R5G6B5) to blend the existing pixel with
	alpha	Blend factor. 0=Use the existing pixel color, 255=Use the specified color
	transformation	Specifies the desired transformation to use for this operation

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 432 of file Bitmap.cpp.

void Bitmap::Blit	(	Bitmap &	target,
		int	x,
		int	y,
		unsigned short	modulate = 0xffff,
		unsigned char	alpha = 255,
		Transformation	transformation = NoTransformation
	)			const [virtual]

This method will blit this bitmap onto the target bitmap at the specified coordinate. It will blit the entire bitmap onto the target, but it will perform clipping on the parts which are outside of the target.

Parameters:

	target	Target bitmap to blit this bitmap onto
	x	X-coordinate in the target bitmap. The top left corner of this bitmap will be drawn at this coordinate on the target bitmap
	y	Y-coordinate in the target bitmap. The top left corner of this bitmap will be drawn at this coordinate on the target bitmap
	modulate	16 bit color value (R5G6B5) to modulate the source pixels with before they are written.
	alpha	Level of transparency the bitmap will be written with. 0=Fully transparent, 255=Fully Opaque
	transformation	Specifies the desired transformation to use for this operation

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 457 of file Bitmap.cpp.

void Bitmap::Blit	(	int	x1,
		int	y1,
		int	x2,
		int	y2,
		Bitmap &	target,
		int	x,
		int	y,
		unsigned short	modulate = 0xffff,
		unsigned char	alpha = 255,
		Transformation	transformation = NoTransformation
	)			const [virtual]

This method will blit a section of this bitmap onto the target bitmap at the specified coordinate. You specify the top-left and bottom-right coordinates of a rectangle you want to blit onto the target. Clipping will be performed on the parts which are outside of the target.

Todo:

This test must take transformations into account

Parameters:

	x1	X-coordinate for the top-left corner of the section of this bitmap which is to be blitted onto the target
	y1	Y-coordinate for the top-left corner of the section of this bitmap which is to be blitted onto the target
	x2	X-coordinate for the bottom-right corner of the section of this bitmap which is to be blitted onto the target
	y2	Y-coordinate for the bottom-right corner of the section of this bitmap which is to be blitted onto the target
	target	Target bitmap to blit this bitmap onto
	x	X-coordinate in the target bitmap. The top left corner of the blitted section will be drawn at this coordinate on the target bitmap
	y	Y-coordinate in the target bitmap. The top left corner of the blitted section will be drawn at this coordinate on the target bitmap
	modulate	16 bit color value (R5G6B5) to modulate the source pixels with before they are written.
	alpha	Level of transparency the bitmap will be written with. 0=Fully transparent, 255=Fully Opaque
	transformation	Specifies the desired transformation to use for this operation

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 465 of file Bitmap.cpp.

void Bitmap::Copy	(	Bitmap &	target,
		int	x,
		int	y,
		unsigned short	modulate = 0xffff,
		Transformation	transformation = NoTransformation
	)			const [virtual]

Parameters:

	target	Target bitmap to blit this bitmap onto
	x	X-coordinate in the target bitmap. The top left corner of this bitmap will be drawn at this coordinate on the target bitmap
	y	Y-coordinate in the target bitmap. The top left corner of this bitmap will be drawn at this coordinate on the target bitmap
	modulate	16 bit color value (R5G6B5) to modulate the source pixels with before they are written.
	transformation	Specifies the desired transformation to use for this operation

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 1292 of file Bitmap.cpp.

void Bitmap::Copy	(	int	x1,
		int	y1,
		int	x2,
		int	y2,
		Bitmap &	target,
		int	x,
		int	y,
		unsigned short	modulate = 0xffff,
		Transformation	transformation = NoTransformation
	)			const [virtual]

Parameters:

	x1	X-coordinate for the top-left corner of the section of this bitmap which is to be blitted onto the target
	y1	Y-coordinate for the top-left corner of the section of this bitmap which is to be blitted onto the target
	x2	X-coordinate for the bottom-right corner of the section of this bitmap which is to be blitted onto the target
	y2	Y-coordinate for the bottom-right corner of the section of this bitmap which is to be blitted onto the target
	target	Target bitmap to blit this bitmap onto
	x	X-coordinate in the target bitmap. The top left corner of the blitted section will be drawn at this coordinate on the target bitmap
	y	Y-coordinate in the target bitmap. The top left corner of the blitted section will be drawn at this coordinate on the target bitmap
	modulate	16 bit color value (R5G6B5) to modulate the source pixels with before they are written.
	transformation	Specifies the desired transformation to use for this operation

Reimplemented in Bitmap_RLE16, and Bitmap_RLE8.

Definition at line 1300 of file Bitmap.cpp.

virtual void Bitmap::Save

(

Asset &

asset

)

const [pure virtual]

Implemented in Bitmap_16bit, Bitmap_16bitAlpha, Bitmap_16bitAlphaCrop, Bitmap_Alpha, Bitmap_RLE16, and Bitmap_RLE8.

virtual void Bitmap::Load

(

const Asset &

asset

)

[pure virtual]

Implemented in Bitmap_16bit, Bitmap_16bitAlpha, Bitmap_16bitAlphaCrop, Bitmap_Alpha, Bitmap_RLE16, and Bitmap_RLE8.

virtual void Bitmap::WriteToAsset

(

Asset *

asset

)

const [pure virtual]

Implemented in Bitmap_16bit, Bitmap_16bitAlpha, Bitmap_16bitAlphaCrop, Bitmap_Alpha, Bitmap_RLE16, and Bitmap_RLE8.

virtual void Bitmap::ReadFromAsset

(

const Asset *

asset

)

[pure virtual]

Implemented in Bitmap_16bit, Bitmap_16bitAlpha, Bitmap_16bitAlphaCrop, Bitmap_Alpha, Bitmap_RLE16, and Bitmap_RLE8.

void Bitmap::TransformCoordinates	(	int &	x,
		int &	y,
		Transformation	transformation
	)			const [protected]

Helper method used to transform a specified (x,y) coordinate to the specified transformation

Parameters:

	x	X-coordinate to transform
	y	Y-coordinate to transform
	transformation	Specifies the desired transformation to use for this operation

Definition at line 285 of file Bitmap.h.

bool Bitmap::Clip	(	int &	sourceX,
		int &	sourceY,
		int &	sourceWidth,
		int &	sourceHeight,
		int &	targetX,
		int &	targetY,
		int	targetWidth,
		int	targetHeight,
		Transformation	transformation
	)			const [protected]

Definition at line 334 of file Bitmap.h.

---

Member Data Documentation

unsigned short* Bitmap::color_ [protected]

Pixel color data (hPitch*vPitch).

Definition at line 407 of file Bitmap.h.

unsigned char* Bitmap::alpha_ [protected]

Pixel alpha data (width*height).

Definition at line 408 of file Bitmap.h.

int Bitmap::width_ [protected]

Width of the bitmap.

Definition at line 409 of file Bitmap.h.

int Bitmap::height_ [protected]

Height of the bitmap.

Definition at line 410 of file Bitmap.h.

int Bitmap::hPitch_ [protected]

Horizontal pitch (dimension) of the bitmap.

Definition at line 411 of file Bitmap.h.

int Bitmap::vPitch_ [protected]

Vertical pitch (dimension) of the bitmap.

Definition at line 412 of file Bitmap.h.

int Bitmap::hOffset_ [protected]

Horizontal offset from bitmap origin to data.

Definition at line 413 of file Bitmap.h.

int Bitmap::vOffset_ [protected]

Vertical offset from bitmap origin to data.

Definition at line 414 of file Bitmap.h.