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This is the online documentation for Colossus Entertainments Pixie Game Engine

Bitmap Class Reference
[Graphics]

List of all members.

Detailed Description

Uncompressed 16-bit color buffer without alpha channel.

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 RLEBitmap, as this can be blitted onto a Bitmap in the same way, but is much, much faster.

Definition at line 30 of file Bitmap.h.


Public Types

enum  Orientation {
  Rotate_0, Rotate_90, Rotate_180, Rotate_270,
  Mirror_X, Mirror_Y, Orientations_Count
}

Public Member Functions

 Bitmap ()
 Bitmap (const Asset &asset)
 Bitmap (int width, int height)
 Bitmap (const Image &image)
 ~Bitmap ()
unsigned short * GetData ()
void Clear ()
void Fill (int x1, int y1, int x2, int y2, unsigned short color, unsigned char alpha=255)
void Fill (unsigned short color, unsigned char alpha=255)
int GetWidth (Orientation orientation=Rotate_0) const
int GetHeight (Orientation orientation=Rotate_0) const
unsigned short GetPixel (int x, int y) const
unsigned short GetPixel (int x, int y, Orientation orientation) const
void SetPixel (int x, int y, unsigned short color, Orientation orientation)
void SetPixel (int x, int y, unsigned short color)
void BlendPixel (int x, int y, unsigned short color, unsigned char alpha, Orientation orientation)
void BlendPixel (int x, int y, unsigned short color, unsigned char alpha)
void Blit (Bitmap *target, int x, int y, unsigned short modulate=0xffff, unsigned char alpha=255, Orientation orientation=Rotate_0) const
void Blit (int x1, int y1, int x2, int y2, Bitmap *target, int x, int y, unsigned short modulate=0xffff, unsigned char alpha=255, Orientation orientation=Rotate_0) const
void Save (Asset &asset) const
void Load (const Asset &asset)
void WriteToAsset (Asset *asset) const
void ReadFromAsset (const Asset *asset)

Public Attributes

unsigned short * data_
 Pixel data (width*height).
int width_
 Width of the bitmap.
int height_
 Height of the bitmap.

Member Enumeration Documentation

enum Bitmap::Orientation

Sometimes it is useful to rotate or flip bitmaps. The methods specified below all take an Orientation 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 orientation parameter to the blit method. All the orientation parameters default to 0 degree rotation, which means untransformed, so just omit the parameter if you don't want to think about orientations...

Enumerator:
Rotate_0  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.
Orientations_Count  Number of available orientations, handy if you want to pick a random one.

Definition at line 105 of file Bitmap.h.

Constructor & Destructor Documentation

Bitmap::Bitmap (  ) 

Definition at line 13 of file Bitmap.cpp.

Bitmap::Bitmap ( const Asset &  asset  ) 

Definition at line 23 of file Bitmap.cpp.

Bitmap::Bitmap ( int  width,
int  height 
)

Creates an empty bitmap with the specified dimensions. All pixels will be set to black (0) at creation.

Parameters:
width  The width of the bitmap, in pixels
height  The height of the bitmap, in pixels

Definition at line 34 of file Bitmap.cpp.

Bitmap::Bitmap ( const Image &  image  ) 

Creates a bitmap from an Image. The width and the height of the bitmap will be taken from the image, the colors reduced from 32 to 16 bits, and the alpha channel is dropped.

Parameters:
image  Image to create bitmap from

Definition at line 46 of file Bitmap.cpp.

Bitmap::~Bitmap (  ) 

Definition at line 68 of file Bitmap.cpp.

Member Function Documentation

unsigned short * Bitmap::GetData (  ) 

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.

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

Definition at line 129 of file Bitmap.cpp.

void Bitmap::Clear (  ) 

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.

Definition at line 137 of file Bitmap.cpp.

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

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).

If the specified area us outside of the bitmap, it will be clipped to the extents of the bitmap.

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

Definition at line 145 of file Bitmap.cpp.

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

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

Definition at line 202 of file Bitmap.cpp.

int Bitmap::GetWidth ( Orientation  orientation = Rotate_0  )  const

Gets the width of the bitmap

Returns:
The width of the bitmap in pixels
Parameters:
orientation  Specifies the desired transformation to use for this operation

Definition at line 79 of file Bitmap.cpp.

int Bitmap::GetHeight ( Orientation  orientation = Rotate_0  )  const

Gets the height of the bitmap

Returns:
The height of the bitmap in pixels
Parameters:
orientation  Specifies the desired transformation to use for this operation

Definition at line 104 of file Bitmap.cpp.

unsigned short Bitmap::GetPixel ( int  x,
int  y 
) const

Gets the 16 bit (R5G6B5) pixel at the specified coordinate of the bitmap

Returns:
The pixel at the specified coordinate
Parameters:
x  X-coordinate of pixel to get
y  Y-coordinate of pixel to get

Definition at line 259 of file Bitmap.cpp.

unsigned short Bitmap::GetPixel ( int  x,
int  y,
Orientation  orientation 
) const

Gets the 16 bit (R5G6B5) pixel at the specified coordinate of the bitmap This version of GetPixel will take an Orientation 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
orientation  Specifies the desired transformation to use for this operation

Definition at line 271 of file Bitmap.cpp.

void Bitmap::SetPixel ( int  x,
int  y,
unsigned short  color,
Orientation  orientation 
)

Changes the pixel at the specified coordinate of the bitmap. This version of SetPixel will take an Orientation 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
orientation  Specifies the desired transformation to use for this operation

Definition at line 247 of file Bitmap.cpp.

void Bitmap::SetPixel ( int  x,
int  y,
unsigned short  color 
)

Changes the pixel at the specified coordinate of the bitmap.

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

Definition at line 236 of file Bitmap.cpp.

void Bitmap::BlendPixel ( int  x,
int  y,
unsigned short  color,
unsigned char  alpha,
Orientation  orientation 
)

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 Orientation 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
orientation  Specifies the desired transformation to use for this operation

Definition at line 303 of file Bitmap.cpp.

void Bitmap::BlendPixel ( int  x,
int  y,
unsigned short  color,
unsigned char  alpha 
)

Blends the pixel at the specified coordinate with the specified color, using the specified alpha value as a blend factor.

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

Definition at line 284 of file Bitmap.cpp.

void Bitmap::Blit ( Bitmap *  target,
int  x,
int  y,
unsigned short  modulate = 0xffff,
unsigned char  alpha = 255,
Orientation  orientation = Rotate_0 
) const

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
orientation  Specifies the desired transformation to use for this operation

Definition at line 370 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,
Orientation  orientation = Rotate_0 
) const

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.

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
orientation  Specifies the desired transformation to use for this operation

Definition at line 378 of file Bitmap.cpp.

void Bitmap::Save ( Asset &  asset  )  const

Definition at line 1151 of file Bitmap.cpp.

void Bitmap::Load ( const Asset &  asset  ) 

Definition at line 1166 of file Bitmap.cpp.

void Bitmap::WriteToAsset ( Asset *  asset  )  const

Definition at line 1199 of file Bitmap.cpp.

void Bitmap::ReadFromAsset ( const Asset *  asset  ) 

Definition at line 1185 of file Bitmap.cpp.

Member Data Documentation

unsigned short* Bitmap::data_

Pixel data (width*height).

Definition at line 287 of file Bitmap.h.

int Bitmap::width_

Width of the bitmap.

Definition at line 288 of file Bitmap.h.

int Bitmap::height_

Height of the bitmap.

Definition at line 289 of file Bitmap.h.