/*

Sample usage of GD on windows. This little program opens a window, fetch its DIB

and assigns to a GD truecolor image.

Thanks to Mateusz Loskot (http://mateusz.loskot.net) for the AttachBuffer function!

$Id$

*/

#include <windows.h>

#include <gd.h>

#include <gdfontg.h>

#include <gdfontl.h>

gdImagePtr gdImageTrueColorAttachBuffer(int* buffer, int sx, int sy, int stride)

{

	int i;

	int height;

	int* rowptr;

	gdImagePtr im;

	im = (gdImage *) malloc (sizeof (gdImage));

	if (!im) {

		return 0;

	}

	memset (im, 0, sizeof (gdImage));

#if 0

	if (overflow2(sizeof (int *), sy)) {

		return 0;

	}

#endif

	im->tpixels = (int **) malloc (sizeof (int *) * sy);

	if (!im->tpixels) {

		free(im);

		return 0;

	}

	im->polyInts = 0;

	im->polyAllocated = 0;

	im->brush = 0;

	im->tile = 0;

	im->style = 0;

	height = sy;

	rowptr = buffer;

	if (stride < 0) {

		int startoff = (height - 1) * stride;

		rowptr = buffer - startoff;

	}

	i = 0;

	while (height--) {

		im->tpixels[i] = rowptr;

		rowptr += stride;

		i++;

	}

	im->sx = sx;

	im->sy = sy;

	im->transparent = (-1);

	im->interlace = 0;

	im->trueColor = 1;

	im->saveAlphaFlag = 0;

	im->alphaBlendingFlag = 1;

	im->thick = 1;

	im->AA = 0;

	im->cx1 = 0;

	im->cy1 = 0;

	im->cx2 = im->sx - 1;

	im->cy2 = im->sy - 1;

	return im;

}

void gdImageDetachBuffer(gdImagePtr im)

{

	free(im->tpixels);

	free(im);

}

BITMAPINFO gdCreateBmp(int width, int height)

{

	BITMAPINFO bmp_info;

	// Configure bitmap properties

	ZeroMemory(&bmp_info, sizeof(BITMAPINFO));

	bmp_info.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);

	bmp_info.bmiHeader.biWidth = width;

	bmp_info.bmiHeader.biHeight = height;

	bmp_info.bmiHeader.biPlanes = 1;

	bmp_info.bmiHeader.biBitCount = 32;

	bmp_info.bmiHeader.biCompression = BI_RGB;

	bmp_info.bmiHeader.biSizeImage = 0;

	bmp_info.bmiHeader.biXPelsPerMeter = 0;

	bmp_info.bmiHeader.biYPelsPerMeter = 0;

	bmp_info.bmiHeader.biClrUsed = 0;

	bmp_info.bmiHeader.biClrImportant = 0;

	return bmp_info;

}

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,

                    PSTR szCmdLine, int iCmdShow)

{

	static TCHAR szAppName[] = TEXT ("Bezier") ;

	HWND         hwnd ;

	MSG          msg ;

	WNDCLASS     wndclass ;

	wndclass.style         = CS_HREDRAW | CS_VREDRAW ;

	wndclass.lpfnWndProc   = WndProc ;

	wndclass.cbClsExtra    = 0 ;

	wndclass.cbWndExtra    = 0 ;

	wndclass.hInstance     = hInstance ;

	wndclass.hIcon         = LoadIcon (NULL, IDI_APPLICATION) ;

	wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;

	wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;

	wndclass.lpszMenuName  = NULL ;

	wndclass.lpszClassName = szAppName ;

	if (!RegisterClass (&wndclass)) {

		// UNICODE-Compilierung ist die einzige realistische Fehlermöglichkeit

		MessageBox (NULL, TEXT ("Programm arbeitet mit Unicode und setzt Windows NT voraus!"),

		            szAppName, MB_ICONERROR) ;

		return 0 ;

	}

	hwnd = CreateWindow (szAppName, TEXT ("Bezierkurven"),

	                     WS_OVERLAPPEDWINDOW,

	                     CW_USEDEFAULT, CW_USEDEFAULT,

	                     CW_USEDEFAULT, CW_USEDEFAULT,

	                     NULL, NULL, hInstance, NULL) ;

	ShowWindow (hwnd, iCmdShow) ;

	UpdateWindow (hwnd) ;

	while (GetMessage (&msg, NULL, 0, 0)) {

		TranslateMessage (&msg) ;

		DispatchMessage (&msg) ;

	}

	return msg.wParam ;

}

void DrawBezier (HDC hdc, POINT apt[])

{

	PolyBezier (hdc, apt, 4) ;

	MoveToEx (hdc, apt[0].x, apt[0].y, NULL) ;

	LineTo   (hdc, apt[1].x, apt[1].y) ;

	MoveToEx (hdc, apt[2].x, apt[2].y, NULL) ;

	LineTo   (hdc, apt[3].x, apt[3].y) ;

}

void gdDrawImage(HDC hdc, RECT *rc)

{

	HDC  mem_dc;

	BITMAPINFO bmp_info;

	void* bits;

	HBITMAP bmp, temp;

	gdImagePtr im;

	int width, height, stride;

	int white, black, blue, red;

	char *s = "Hello world!";

	gdFontPtr lfont, gfont;

	width = rc->right - rc->left;

	height = rc->bottom - rc->top;

	bmp_info = gdCreateBmp(width, height);

	// Create memory device context

	mem_dc = CreateCompatibleDC(hdc);

	if (!mem_dc) {

		MessageBox(NULL, "Can't create a compatible DC!", "Error!", MB_ICONEXCLAMATION | MB_OK);

		return;

	}

	// bits points to a shared buffer of pixels

	bits = NULL;

	bmp = CreateDIBSection(mem_dc, &bmp_info, DIB_RGB_COLORS, (void**)&bits, 0, 0);

	// Selecting the object before doing anything allows you to use libgd

	// together with native Windows GDI.

	temp = (HBITMAP)SelectObject(mem_dc, bmp);

	/*stride = ((width * 1 + 3) >> 2) << 2;*/

	// always uses 32bit in BMPINFO

	stride = width;

	im = NULL;

	// Attach shared buffer of pixels to GD image

	// Negative stride places 0,0 in upper-left corner

	im = gdImageTrueColorAttachBuffer((int*)bits, width, height, -stride);

	if (!im) {

		MessageBox(NULL, "GD image creation failed!", "Error!", MB_ICONEXCLAMATION | MB_OK);

		return;

	}

	// Start of GD drawing

	white = gdImageColorAllocate(im, 255, 255, 255);

	black = gdImageColorAllocate(im, 0, 0, 0);

	blue = gdImageColorAllocate(im, 0, 0, 255);

	// Allocate the color red, 50% transparent.

	red = gdImageColorAllocateAlpha(im, 255, 0, 0, 64);

	// Erase background with white color

	gdImageFilledRectangle(im, 0, 0, width, height, 0xFF0000);

	lfont = gdFontGetLarge();

	gfont = gdFontGetGiant();

	// Draw a dashed line from the upper left corner to the lower right corner.

	gdImageFilledRectangle(im, 25, 25, 100, 100, blue);

	gdImageChar(im, gfont, 35, 35, 'Q', white);

	gdImageFilledRectangle(im, 50, 50, 75, 175, red);

	gdImageLine(im, 0, 0, 150, 150, black);

	gdImageString(im, gdFontGetLarge(),

	              im->sx / 2 - (strlen(s) * lfont->w / 2),

	              im->sy / 2 - lfont->h / 2,

	              (unsigned char*)s, black);

	// Copy drawing from memory context (shared bitmap buffer) to screen DC.

	BitBlt(hdc, rc->left, rc->top, width, height, mem_dc, 0, 0, SRCCOPY);

	// Free

	gdImageDetachBuffer(im);

	SelectObject(mem_dc, temp);

	DeleteObject(bmp);

	DeleteObject(mem_dc);

}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)

{

	static POINT apt[4] ;

	HDC          hdc ;

	int          cxClient, cyClient ;

	PAINTSTRUCT  ps ;

	RECT rc;

	GetClientRect(hwnd, &rc);

	switch (message) {

	case WM_SIZE:

		cxClient = LOWORD (lParam) ;

		cyClient = HIWORD (lParam) ;

		apt[0].x = cxClient / 4 ;

		apt[0].y = cyClient / 2 ;

		apt[1].x = cxClient / 2 ;

		apt[1].y = cyClient / 4 ;

		apt[2].x =     cxClient / 2 ;

		apt[2].y = 3 * cyClient / 4 ;

		apt[3].x = 3 * cxClient / 4 ;

		apt[3].y =     cyClient / 2 ;

		return 0 ;

	case WM_LBUTTONDOWN:

	case WM_RBUTTONDOWN:

	case WM_MOUSEMOVE:

		if (wParam & MK_LBUTTON || wParam & MK_RBUTTON) {

			hdc = GetDC (hwnd) ;

			// alte Kurve löschen (mit Weiß übermalen)

			SelectObject (hdc, GetStockObject (WHITE_PEN)) ;

			DrawBezier (hdc, apt) ;

			if (wParam & MK_LBUTTON) {

				apt[1].x = LOWORD (lParam) ;

				apt[1].y = HIWORD (lParam) ;

			}

			if (wParam & MK_RBUTTON) {

				apt[2].x = LOWORD (lParam) ;

				apt[2].y = HIWORD (lParam) ;

			}

			// neue Kurve (mit Schwarz) zeichnen

			SelectObject (hdc, GetStockObject (BLACK_PEN)) ;

			gdDrawImage(hdc, &rc);

			DrawBezier (hdc, apt) ;

			ReleaseDC (hwnd, hdc) ;

		}

		return 0 ;

	case WM_PAINT:

		hdc = BeginPaint (hwnd, &ps) ;

		GetClientRect(hwnd, &rc);

		gdDrawImage(hdc, &rc);

		DrawBezier (hdc, apt) ;

		EndPaint (hwnd, &ps) ;

		return 0 ;

	case WM_DESTROY:

		PostQuitMessage (0) ;

		return 0 ;

	}

	return DefWindowProc (hwnd, message, wParam, lParam) ;

}