create Winapi Bitmaps Manually Using Pixel Arrays

Create 16/24BPP HBITMAP from pixel array

Hi. I'm interesting in creating 16/24BPP WinAPI Bitmaps manually for a custom
image file format. My CreateBitmap(...) code works for 32BPP, but not 16/24BPP.

Code:

/* Create 32BPP HBITMAP manually from pixel array */ #pragma optimize("t", on) #define WIN32_LEAN_AND_MEAN #include <windows.h> #define name "Create HBITMAP" int screenw, screenh; HINSTANCE instance; HWND window; HDC sdc; LRESULT CALLBACK wproc(HWND w, UINT m, WPARAM wp, LPARAM lp); HBITMAP hbmp; const unsigned w=0xFFFFFF, b=0, y=0xFFFF00; // colors: white, black, yellow unsigned bmp[] = { // example 8x8 face image w,w,b,b,b,b,w,w, w,b,y,y,y,y,b,w, b,y,b,y,y,b,y,b, b,y,b,y,y,b,y,b, b,y,y,y,y,y,y,b, b,y,b,b,b,b,y,b, w,b,y,y,y,y,b,w, w,w,b,b,b,b,w,w }; int WINAPI WinMain(HINSTANCE hi, HINSTANCE na, PSTR c, int na2) { instance = hi; screenw = GetSystemMetrics(SM_CXSCREEN); screenh = GetSystemMetrics(SM_CYSCREEN); WNDCLASSEX wc = { 0x30, 0x23, wproc, 0, 0, hi, 0, (HCURSOR) LoadCursor(0, IDC_ARROW), (HBRUSH) GetStockObject(WHITE_BRUSH), 0, name, 0 }; if (!RegisterClassEx(&wc) || !(window = CreateWindowEx(0, name, name, WS_POPUP|WS_VISIBLE, screenw/2-4, screenh/2-4, 8, 8, 0, 0, hi, 0))) return 1; hbmp = CreateBitmap(8, 8, 32, 1, bmp); MSG msg; for (;;) { if (!GetMessage(&msg, 0, 0, 0)) return msg.wParam; TranslateMessage(&msg); DispatchMessage(&msg); } return msg.wParam; } LRESULT CALLBACK wproc(HWND w, UINT m, WPARAM wp, LPARAM lp) { if (m == WM_KEYDOWN && wp == VK_ESCAPE) PostQuitMessage(0); else if (m == WM_PAINT) { HDC dc = GetDC(window), mdc = CreateCompatibleDC(dc); SelectObject(mdc, hbmp); BitBlt(dc, 0, 0, 8, 8, mdc, 0, 0, SRCCOPY); ReleaseDC(window, dc); DeleteDC(mdc); } return DefWindowProc(w, m, wp, lp); }

Here is a quote from MSDN:

Quote:

For a 16 bpp or 32 bpp non-palletized image, the color table must be three entries long; the entries must specify the value of the red, green, and blue (RGB) bitmasks. Because GDI ignores the color table for 24-bpp bitmaps, you should store the image pixels in RGB format.

This doesn't even make sense. 15/16/24/32BPP do not have a palette. I know what bitmasks are -- ie, 11111.000000.00000 = R16 -- but what does that have to do with creating an image?

Any help would be appreciated. Thank you.

> the entries must specify the value of the red, green, and blue (RGB) bitmasks.
Like it says, a 3 entry table
red would be 0xF800
green would be 0x07E0
blue would be 0x001F
correponding to the masks it takes to extract an RGB from each 16-bit number in the pixel data.

Hi Salem. Thanks for responding.

What do they mean by "entries"? I assume they are referring to index 1 of the palette[0]. This would correspond to bytes 0-1 (16BPP) or 0-2 (24BPP), but it was not necessary in the 32BPP example I provided, despite the quote from MSDN: "For a 16 bpp or 32 bpp non-palletized image, the color table must be three entries long".

All I'm trying to do is create a HBITMAP from a pixel array in 16/24/32BPP, then access the pixels directly. Anyone know how to do this?

With my DOS 32BIT VESA library, I can easily create/draw/rotate/etc images, but I am not very experienced with Windows API. I use DirectDraw and custom controls/interfaces for all my applications.

Ok, here's what I have so far. The DirectDraw version works, but the WinAPI HBITMAP version does not.

Code:

/**************************** IMAGE.H ***************************/ #define DD // default //#define WIN // does not work // IMAGE STRUCTURE, 24/32 BYTES typedef struct { byte type[3], system; // type = 0. system = 0=WIN, 1=DD, 2+=reserved dword x, y, w, h; // location, size union { // pixels HBITMAP hbmp; IDirectDrawSurface *surface; } } IMAGE; // LOAD, DRAW, CREATE, GET/SET PIXEL/S void loadi(IMAGE *i, char *fn); // load .bmp/.tga/.i void drawi(IMAGE *i); // draw to current screen int newi(IMAGE *i, int w, int h, int bpp); // create blank image int geti(IMAGE *i, void *data); // get all pixels int seti(IMAGE *i, void *data); // set all pixels dword getpi(IMAGE *i, int x, int y); // get pixel at void setpi(IMAGE *i, int x, int y, dword c); // set pixel at int copyi(IMAGE *i, IMAGE *i2); // copy i pixels to i2 int formati(IMAGE *i, int bpp, void *pal); // convert to 1/2/4/8/15/16/24/32BPP // pal/lette only if <= 8 void killi(IMAGE *i); // delete // MOVE, SIZE, FLIP, ROTATE void movei(IMAGE *i, int x, int y); // set location void movei(IMAGE *i, double vx, double vy); // move by velocity void sizei(IMAGE *i, int w, int h); // size pixels void sizei(IMAGE *i, double percent); // size by percent void sizewi(IMAGE *i, int w); // size w void sizehi(IMAGE *i, int h); // same with h void setsizei(int antialias, int maintain); // set sizex(IMAGE *i, ...) // properties: use antialias? 1/0. maintain proportions for sizehi/sizewi? 1/0 void canvasi(IMAGE *i, // set canvas side insets, +/- int l, int t, int r, int b); void flipi(IMAGE *i, int d); // flip HORIZONTAL/VERTICAL void rotatei(IMAGE *i, int d); // rotate LEFT/RIGHT/CORNERS void rotateai(IMAGE *i, int degree); // rotate arbitrary, 0-359 void polyi(IMAGE *i, XY *points, // create 2D polygon based on int x, int y, int accuracy); // pixel at XY (for masks/fills). // accuracy=1-100% // LIGHT, COLOR, EFFECTS void lighti(IMAGE *i, int n); // adjust light/darkness, -100 to 100% void huei(IMAGE *i, int n); // adjust hue, 0-359 void saturatei(IMAGE *i, int n); // adjust gray/pure, -100 to 100% void morei(IMAGE *i, int c, int n); // more RGB. c=RED/GREEN/BLUE. n = 1-100% void replacei(IMAGE *i, dword c, // replace all appearances of c with c2 dword c2, int accuracy); // accuracy = 1-100% (for "hue map" feature) void alphai(IMAGE *i, int n); // adjust alpha. n = 0/opaque or 1-100% void contrasti(IMAGE *i, int n); // sharpen/blur, -100 to 100

A bunch of function prototypes isn't going to help us figure out what you've done.

Post your WinAPI version of the code which deals with bitmaps.

Ken - "Please just stick to code tags - the universally applied extra fonts and bold type are overkill" - I use a text preprocessor that automatically formats code to Courier New bold 10, which is standard in 640x480 or 800x600. Sorry if it looks "overkill" *on your PC* or PDA, cell phone, etc.

Salem - "Post your WinAPI version of the code which deals with bitmaps" - The very first example creates a 8x8x32 HBITMAP then displays it.