BITMAP and blitting operations
[GDI functions]

Functions

Detailed Description

Example:

{
    int tox = 800, toy = 800;
    int count;
    BITMAP bitmap;
    unsigned int start_tick, end_tick;

    /* Load the bitmap from the file. */
    if (LoadBitmap (hdc, &bitmap, "res/icon.bmp"))
        return;

    bitmap.bmType = BMP_TYPE_ALPHACHANNEL;

    /* Fill a box with the bitmap with alpha channel. */
    start_tick = GetTickCount ();
    count = 1000;
    while (count--) {
        tox = rand() % 800;
        toy = rand() % 800;

        /* Set a random alpha channel. */
        bitmap.bmAlpha = rand() % 256;
        /* Fill the box. */
        FillBoxWithBitmap (hdc, tox, toy, 0, 0, &bitmap);
    }
    end_tick = GetTickCount ();
    TellSpeed (hwnd, start_tick, end_tick, "Alpha Blended Bitmap", 1000);

    bitmap.bmType = BMP_TYPE_ALPHACHANNEL | BMP_TYPE_COLORKEY;
    /* Set the color key (the transparent pixel) of the bitmap. */
    bitmap.bmColorKey = GetPixelInBitmap (&bitmap, 0, 0);

    /* Fill a box with the bitmap with alpha channel and color key. */
    start_tick = GetTickCount ();
    count = 1000;
    while (count--) {
        tox = rand() % 800;
        toy = rand() % 800;

        /* Set a random alpha channel. */
        bitmap.bmAlpha = rand() % 256;
        /* Fill the box. */
        FillBoxWithBitmap (hdc, tox, toy, 0, 0, &bitmap);
    }
    end_tick = GetTickCount ();
    TellSpeed (hwnd, start_tick, end_tick, "Alpha Blended Transparent Bitmap", 1000);

    UnloadBitmap (&bitmap);
}

{
    /* Create a memory DC which hanve alpha per-pixel. */
    mem_dc = CreateMemDC (400, 100, 16, MEMDC_FLAG_HWSURFACE | MEMDC_FLAG_SRCALPHA,
                    0x0000F000, 0x00000F00, 0x000000F0, 0x0000000F);

    /* Set brush color and fill a box. */
    SetBrushColor (mem_dc, RGBA2Pixel (mem_dc, 0xFF, 0xFF, 0x00, 0xFF));
    FillBox (mem_dc, 0, 0, 200, 50);

    /* Set another brush color and fill a box */
    SetBrushColor (mem_dc, RGBA2Pixel (mem_dc, 0xFF, 0xFF, 0x00, 0x40));
    FillBox (mem_dc, 200, 0, 200, 50);

    /* Set another brush color and fill a box */
    SetBrushColor (mem_dc, RGBA2Pixel (mem_dc, 0xFF, 0xFF, 0x00, 0x80));
    FillBox (mem_dc, 0, 50, 200, 50);

    /* Set another brush color and fill a box */
    SetBrushColor (mem_dc, RGBA2Pixel (mem_dc, 0xFF, 0xFF, 0x00, 0xC0));
    FillBox (mem_dc, 200, 50, 200, 50);
    SetBkMode (mem_dc, BM_TRANSPARENT);

    /* Set a text color and output the text */
    SetTextColor (mem_dc, RGBA2Pixel (mem_dc, 0x00, 0x00, 0x00, 0x80));
    TabbedTextOut (mem_dc, 0, 0, "Memory DC with alpha.\n"
                                 "The source DC have alpha per-pixel.");

    /* Blitting to a client DC. */
    start_tick = GetTickCount ();
    count = 100;
    while (count--) {
        BitBlt (mem_dc, 0, 0, 400, 100, hdc, rand () % 800, rand () % 800);
    }
    end_tick = GetTickCount ();
    TellSpeed (hwnd, start_tick, end_tick, "Alpha Blit", 100);

    /* delete the momory DC. */
    DeleteMemDC (mem_dc);
}

Function Documentation

void GUIAPI BitBlt ( HDC  hsdc,
int  sx,
int  sy,
int  sw,
int  sh,
HDC  hddc,
int  dx,
int  dy,
DWORD  dwRop 
)

Performs a bit-block transfer from a device context into another device context.

This function performs a bit-block transfer of the color data cooresponding to a rectangle of pixels from the specified source device context hsdc into a destination device context hddc. (sx,sy,sw,sh) specifies the rectangle in the source DC, and (dx,dy) specifies the position of the rectangle in the destination DC. Note that the size of the two rectangles are identical.

Note that all coordinates should be in the device space.

Parameters:
hsdc The source device context.
sx The x coordinate of the upper-left corner of the rectangle in the source DC.
sy The y coordinate of the upper-left corner of the rectangle in the source DC.
sw The width of the source rectangle.
sh The height of the source rectangle.
hddc The destination device context hddc.
dx The x coordinate of the upper-left corner of the rectangle in the destination DC.
dy The y coordinate of the upper-left corner of the rectangle in the destination DC.
dwRop The raster operation, currently ignored.
Note:
The alpha and color key settings of the source DC will come into play.
See also:
StretchBlt, SetMemDCAlpha, SetMemDCColorKey
BOOL FillBitmapPartInBox ( HDC  hdc,
int  box_x,
int  box_y,
int  box_w,
int  box_h,
const BITMAP *  pbmp,
int  bmp_x,
int  bmp_y,
int  bmp_w,
int  bmp_h 
)

Fills a part of bitmap into a box, and the parts bitmap will be scaled if needed.

This function gives an intuitionistic way to use function FillBoxWidthBitmapPart.

Parameters:
hdc The target DC to show bitmap
box_x The left of target box
box_y The top of target box
box_w The width of target box
box_h The height of target box
pbmp The bitmap which will be showed in the hdc
bmp_x The visible part's left of bitmap
bmp_y The visible part's top of bitmap
bmp_w The visible part's width of bitmap
bmp_h The visible part's height of bitmap
See also:
FillBoxWidthBitmapPart
BOOL GUIAPI FillBoxWithBitmap ( HDC  hdc,
int  x,
int  y,
int  w,
int  h,
const BITMAP *  bmp 
)

Fills a box with a BITMAP object.

This function fills a box with a BITMAP object pointed to by bmp. (x,y) is the upper-left corner of the box, and w, h are the width and the height of the box respectively.

This function will scale the bitmap when necessary; that is, when the width or the height of the box is not equal to the with or the height of the BITMAP object.

Parameters:
hdc The device context.
x The x coordinate of the upper-left corner of the box.
y The y coordinate of the upper-left corner of the box.
w The width of the box. Can be zero, means the width or the height will be equal to the width or the height of the BITMAP object.
h The height of the box. Can be zero, means the width or the height will be equal to the width or the height of the BITMAP object.
bmp The pointer to the BITMAP object.
Returns:
TRUE on success, otherwise FALSE.
Note:
You can specify the alpha value or the color key of the BITMAP object, and the current raster operation was set by SetRasterOperation for the DC will override the alpha value of color key if ROP is not ROP_SET.
If the bitmap has BMP_TYPE_RLE, the target w and h will be ignored. That is, the scale of the bitmap is not supported for RLE encoded bitmap.
See also:
FillBoxWithBitmapPart, GetBitmapFromDC, Bitmap file load/save operations
BOOL GUIAPI FillBoxWithBitmapPart ( HDC  hdc,
int  x,
int  y,
int  w,
int  h,
int  bw,
int  bh,
const BITMAP *  bmp,
int  xo,
int  yo 
)

Fills a box with a part of a bitmap oject.

This function fills a box with a part of a bitmap object pointed to by bmp. (x,y) is the upper-left corner of the box, and w, h are the width and the height of the box respectively. (xo, yo) is the start position of the part box in the bitmap relative to upper-left corner of the bitmap, and bw, bh are the width and the height of the full bitmap expected.

If bw or bh is less than or equal to zero, this function will use the original width and height of the bitmap, else it will scale the BITMAP object when necessary; that is, when bw or bh is not equal to the width or the height of the BITMAP object.

Parameters:
hdc The device context.
x The x coordinate of the upper-left corner of the box.
y The y coordinate of the upper-left corner of the box.
w The width of the box.
h The height of the box.
bw The width of the full bitmap expected. Can be zero, means the width or the height will be equal to the width or the height of the BITMAP object.
bh The height of the full bitmap expected. Can be zero, means the width or the height will be equal to the width or the height of the BITMAP object.
xo xo,yo: The start position of the part box in the bitmap relative to upper-left corner of the BITMAP object.
yo xo,yo: The start position of the part box in the bitmap relative to upper-left corner of the BITMAP object.
bmp The pointer to the BITMAP object.
Returns:
TRUE on success, otherwise FALSE.
Note:
1: You can specify the alpha value or the color key of the BITMAP object, and the current raster operation was set by SetRasterOperation for the DC will override the alpha value or the color key if ROP is not ROP_SET.
2: xo/yo must be greater zero and (xo + w) < bw, (yo + h) < bh. else with fill nothing.
3: xo/yo must be multiply scale factor when bitmap scaled.
4: if bw or bh is not equal to he width or the height of the BITMAP object, it will be scale bitmap, but fill box is also (0, 0, w,h).
The RLE encoded bitmap is not supported by this function so far.
See also:
FillBoxWithBitmap, GetBitmapFromDC, Bitmap structure
BOOL GUIAPI GetBitmapFromDC ( HDC  hdc,
int  x,
int  y,
int  w,
int  h,
BITMAP *  bmp 
)

Gets image box on a DC and saves it into a BITMAP object.

This function gets image box on the specified device context hdc, and saves the image bits into the BITMAP object pointed to by bmp. The image box begins at (x,y), and is w wide and h high. You must make sure that bmp->bits is big enough to store the image.

Parameters:
hdc The device context.
x The x coordinate in pixels of upper-left corner of the image box.
y The y coordinate in pixels of upper-left corner of the image box.
w The width of the image box.
h The height of the image box.
bmp The pointer to the BITMAP object.
Note:
If BITMAP's bmPitch is zero or bmBits is NULL, it will be malloc bmBits internal, you need init the BITMAP surely(such as InitBitmap) or memset(bmp, 0, sizeof(BITMAP)). 
 void GUIAPI SaveScreenBox (int x, int y, int w, int h, void* vbuf)
See also:
FillBoxWithBitmap, Bitmap structure
static inline gal_pixel GUIAPI GetPixelInBitmap ( const BITMAP *  bmp,
int  x,
int  y 
) [inline, static]

Returns the pixel value in a BITMAP object.

This function returns the pixel value at the position (x,y) in the BITMAP object bmp.

Parameters:
bmp The BITMAP object.
x x,y: The position of the pixel in the bitmap relative to the upper-left corner of the bitmap.
y x,y: The position of the pixel in the bitmap relative to the upper-left corner of the bitmap.
Returns:
The pixel value, if the position is out of the bitmap, zero returned.
See also:
SetPixelInBitmap, Bitmap structure

Definition at line 4859 of file gdi.h.

References GetPixelInBitmapEx(), and NULL.

gal_pixel GUIAPI GetPixelInBitmapEx ( const BITMAP *  bmp,
int  x,
int  y,
Uint8 *  alpha 
)

Returns the pixel value in a BITMAP object.

This function returns the pixel value and alpha at the position (x,y) in the BITMAP object bmp.

Parameters:
bmp The BITMAP object.
x x,y: The position of the pixel in the bitmap relative to the upper-left corner of the bitmap.
y x,y: The position of the pixel in the bitmap relative to the upper-left corner of the bitmap.
alpha The point to alpha of position (x, y).
Returns:
The pixel value, if the position is out of the bitmap, zero returned.
Note:
if the bitmap with BMP_TYPE_ALPHA_MASK flag, the alpha value will be read from bmp->AlphaMask(Bitmap Alpha Mask array).
See also:
SetPixelInBitmapEx, Bitmap structure

Referenced by GetPixelInBitmap().

BOOL GUIAPI SaveMainWindowContent ( HWND  hWnd,
const char *  filename 
)

Saves content of a main window to a file.

This function saves the content of the main window hWnd to the image file filename. MiniGUI uses the extension name of the file to determine the format of the image file.

Parameters:
hWnd Handle to the main window.
filename The name of the image file.
Returns:
TRUE on success, otherwise FALSE.
Note:
Only defined for _MGMISC_SAVESCREEN.
See also:
Bitmap file load/save operations
BOOL GUIAPI SaveScreenRectContent ( const RECT *  rc,
const char *  filename 
)

Saves content of a rectangle in the screen to a file.

This function saves the content of the rect rc to the image file filename. MiniGUI uses the extension name of the file to determine the format of the image file.

Parameters:
rc The RECT object defined the rectangle in the screen.
filename The name of the image file.
Returns:
TRUE on success, otherwise FALSE.
Note:
Only defined for _MGMISC_SAVESCREEN.
See also:
Bitmap file load/save operations
BOOL GUIAPI ScaleBitmapEx ( BITMAP *  dst,
const BITMAP *  src,
HDC  ref_dc 
)

Scales a BITMAP object into another BITMAP object by specify algorithm.

This function scales a BITMAP object src into another BITMAO object dst by specify algorithm. The source rectangle and the destination rectangle both are defined in the BITMAP objects.

Parameters:
dst The destination BITMAP object.
src The srouce BITMAP object.
ref_dc The device context of Bitmap's relative device dc.
Returns:
TRUE on success, otherwise FALSE.
Note:
you should init the dst Bitmap first, such as bmPitch and bmBits.
See also:
FillBoxWithBitmap, StretchBlt, Bitmap structure
static inline BOOL GUIAPI SetPixelInBitmap ( const BITMAP *  bmp,
int  x,
int  y,
gal_pixel  pixel 
) [inline, static]

Sets pixel value in a BITMAP object.

This function sets the pixel value at the position (x,y) in the BITMAP object bmp.

Parameters:
bmp The BITMAP object.
x x,y: The position of the pixel in the bitmap relative to the upper-left corner of the bitmap.
y x,y: The position of the pixel in the bitmap relative to the upper-left corner of the bitmap.
pixel The pixel value.
Returns:
TRUE on success. If the position is out of the bitmap, FALSE returned.
See also:
GetPixelInBitmap, Bitmap structure

Definition at line 4911 of file gdi.h.

References NULL.

void GUIAPI StretchBlt ( HDC  hsdc,
int  sx,
int  sy,
int  sw,
int  sh,
HDC  hddc,
int  dx,
int  dy,
int  dw,
int  dh,
DWORD  dwRop 
)

Copies a bitmap from a source rectangle into a destination rectangle, streches the bitmap if necessary.

This function copies a bitmap from a source rectangle into a destination rectangle, streching or compressing the bitmap to fit the dimension of the destination rectangle, if necessary. This function is similar with

See also:
BitBlt function except the former scaling the bitmap. (dw,dh) specifies the size of the destination rectangle.
Parameters:
hsdc The source device context.
sx The x coordinate of the upper-left corner of the rectangle in the source DC.
sy The y coordinate of the upper-left corner of the rectangle in the source DC.
sw The width of the source rectangle.
sh The height of the source rectangle.
hddc The destination device context hddc.
dx The x coordinate of the upper-left corner of the rectangle in the destination DC.
dy The y coordinate of the upper-left corner of the rectangle in the destination DC.
dw The width of the destination rectangle.
dh The height of the destination rectangle.
dwRop The raster operation, currently ignored.
Note:
The source rect should be contained in the device space entirely, and all coordinates should be in the device space.
The source DC and dest DC must compatible, else will do nothing.
The alpha and color key settings of the source DC will not come into play.
See also:
BitBlt, SetMemDCAlpha, SetMemDCColorKey
Generated on Thu Apr 7 16:01:48 2011 for MiniGUI V3.0.12 API Reference by  doxygen 1.6.3