CBitmap

CBitmap is a C++ class that is provided to display bitmaps.

Constructors

CBitmap(void);
CBitmap(const string& strFilename);
CBitmap(const char* pszfilename);

The constructors with a passed filename create a CBitmap object and load the file into memory.

Parameters

• strFilename - filename
• pszFilename - filename

Examples

CBitmap image("/mnt/nand/apps/myapp/myapp.bmp");

string strFile = "/mnt/nand/apps/myapp/myapp.bmp";
CBitmap image(strFile);

CBitmap image;

This constructs the bitmap object without loading any file yet.

Member Functions

LoadBitmp

Opens a specified file.

int LoadBitmap(const string& strFilename);
int LoadBitmap(const char* pszFilename);

Parameters

• strFilename - filename
• pszFilename - filename

Return Value

0 successful -2 file cannot be opened -3 bitmap header cannot be read -4 bitmap info cannot be read -5 width is greater than 640, height is greater than 480, or bitmap is not 8 bits per pixel. -6 color palette cannot be read -7 Too many colors in palette

Remarks

Example

CBitmap bitamp;
if(bitmap.LoadBitmap("/mnt/nand/apps/myapp/myapp.bmp") != 0)
{
    DisplayText(0, 0, "Error loading bitmap");
}

DeleteBitmap

Deletes memory in RAM allocated to the bitmap. This does not delete the file.

void DeleteBitmap(void);

Parameters

Function does not accept any parameters

Return Value

Function does not return any result.

Remarks

Example

CBitmap bitmap("/mnt/nand/apps/myapp/myapp.bmp");
bitmap.Draw(0, 0);
SleepSeconds(1);
ClearLCD();
bitmap.DeleteBitmap();

Draw

Draws the bitmap on the LCD display

void Draw(int x, int y);

Parameters

x - The X coordinate for the left side of the bitmap to be displayed y - The Y coordinate for the top of the bitmap to be displayed

Return Value

Function does not return any result.

Remarks

Example

CBitmap bitmap("/mnt/nand/apps/myapp/myapp.bmp");
bitmap.Draw(0, 0);

GetWidth

Get the width of the bitmap in pixels

int GetWidth(void);

Parameters

Function does not accept any parameters.

Return Value

Function returns the width of the bitmap in pixels.

Remarks

Example

CBitmap bitmap("/mnt/nand/apps/myapp/myapp.bmp");
int x = bitmap.GetWidth();

GetHeight

Get the height of the bitmap in pixels

int GetHeight(void);

Parameters

Function does not accept any parameters.

Return Value

Function returns the height of the bitmap in pixels.

Remarks

Example

CBitmap bitmap("/mnt/nand/apps/myapp/myapp.bmp");
int y = bitmap.GetHeight();

GetColorCnt

Get the number of colors the bitmap uses

int GetColorCnt(void);

Parameters

Function does not accept any parameters.

Return Value

Function returns the number of colors used by the bitmap.

Remarks

Example

CBitmap bitmap("/mnt/nand/apps/myapp/myapp.bmp");
int n = bitmap.GetColorCnt();

GetColorsAdded

Get the numbers of colors added to the 825 global palette when the bitmap was loaded

int GetColorsAdded(void);

Parameters

Function does not accept any parameters.

Return Value

Function returns the number of colors added to the 825 global palette when the bitmap was loaded.

Remarks

Example

CBitmap bitmap("/mnt/nand/apps/myapp/myapp.bmp");
int n = bitmap.GetColorsAdded();

GetError

Get the error code

int GetError(void);

Parameters

Function does not accept any parameters.

Return Value

Function returns the current error code.

Remarks

Example

CBitmap bitmap("/mnt/nand/apps/myapp/myapp.bmp");
int err = bitmap.GetError();
if(err != 0)
{
   DisplayText(0, 0, "Error loading bitmap");
}

ReclaimColors

Reclaim custom colors added by loading bitmaps

static void ReclaimColors(void);

Parameters

Function does not accept any parameters.

Return Value

Function does not return any value.

Remarks

In 8 bits per pixel mode all bitmaps and text or other graphics on the display at any given time must share a palette of 256 colors. ReclaimColors releases the colors that were added by displaying bitmaps.

Example

CBitmap img1("/mnt/nand/apps/myapp/img1.bmp");
CBitmap img2("/mnt/nand/apps/myapp/img2.bmp");
img1.Draw(0, 0);
img2.Draw(320, 0);

SleepSeconds(5);
ClearLCD();
img1.DeleteBitmap();
img2.DeleteBitmap();

CBitmap::ReclaimColors();

CBitmap img3("/mnt/nand/apps/myapp/img3.bmp");
CBitmap img4("/mnt/nand/apps/myapp/img4.bmp");
img3.Draw(0, 0);
img4.Draw(320, 0);