Add the windows display functionality.

1 files changed, 207 insertions, 0 deletions

diff --git a/dmagick/internal/Windows.d b/dmagick/internal/Windows.d
new file mode 100644
index 0000000..1358253
--- /dev/null
+++ b/dmagick/internal/Windows.d
@@ -0,0 +1,207 @@
+/**
+ * Copyright: Mike Wey 2011
+ * License:   zlib (See accompanying LICENSE file)
+ * Authors:   Mike Wey
+ */
+ 
+module dmagick.internal.Windows;
+
+import core.sys.windows.windows;
+
+import dmagick.Image;
+import dmagick.Exception;
+import dmagick.Geometry;
+
+Window[HWND] windows;
+
+class Window
+{
+	Image image;
+	size_t height;
+	size_t width;
+	
+	WNDCLASS  wndclass;
+	HINSTANCE hInstance;
+	HWND      hwnd;
+	MSG       msg;
+
+	this(Image image)
+	{
+		this.image = image;
+		
+		height = image.rows;
+		width = image.columns;
+		
+		hInstance = cast(HINSTANCE) GetModuleHandleA(null);
+		
+		wndclass.style         = CS_HREDRAW | CS_VREDRAW;
+		wndclass.lpfnWndProc   = &WndProc;
+		wndclass.cbClsExtra    = 0;
+		wndclass.cbWndExtra    = 0;
+		wndclass.hInstance     = hInstance;
+		wndclass.hIcon         = LoadIconA(null, IDI_APPLICATION);
+		wndclass.hCursor       = LoadCursorA(null, IDC_ARROW);
+		wndclass.hbrBackground = null;
+		wndclass.lpszMenuName  = "DMagick";
+		wndclass.lpszClassName = "DMagick";
+
+		if (!RegisterClassA(&wndclass))
+			throw new DMagickException("This program requires Windows NT!");
+
+		RECT rect = RECT(0,0, width,height);
+		AdjustWindowRect(&rect, WS_OVERLAPPEDWINDOW, false);
+		
+		hwnd = CreateWindowA("DMagick", "DMagick", WS_OVERLAPPEDWINDOW,
+			CW_USEDEFAULT, CW_USEDEFAULT, rect.right-rect.left, rect.bottom-rect.top,
+			null, null, hInstance, null);
+
+		windows[hwnd] = this;
+	}
+	
+	void display()
+	{
+		ShowWindow(hwnd, SW_SHOWNORMAL);
+		UpdateWindow(hwnd);
+
+		while (GetMessageA(&msg, null, 0, 0))
+		{
+			TranslateMessage(&msg);
+			DispatchMessageA(&msg);
+		}
+	}
+	
+	extern(Windows) static LRESULT WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
+	{
+		static int cxClient, cyClient, cxSource, cySource;
+		int x, y;
+		HDC hdc;
+		PAINTSTRUCT ps;
+
+		static HDC     hdcMem;
+		static HBITMAP hbmMem;
+		static HANDLE  hOld;
+		RECT rect;
+		
+		switch (message)
+		{
+			case WM_SIZE:
+				cxClient = LOWORD(lParam);
+				cyClient = HIWORD(lParam);
+				return 0;
+
+			case WM_ERASEBKGND:  // don't redraw bg
+				return 1;
+			
+			case WM_PAINT:
+			{
+				// Get DC for window
+				hdc = BeginPaint(hwnd, &ps);
+
+				// Create an off-screen DC for double-buffering
+				hdcMem = CreateCompatibleDC(hdc);
+				hbmMem = CreateCompatibleBitmap(hdc, cxClient, cyClient);
+				hOld = SelectObject(hdcMem, hbmMem);
+			
+				// Draw into hdcMem
+				GetClientRect(hwnd, &rect);
+				FillRect(hdcMem, &rect, GetStockObject(BLACK_BRUSH));
+				
+				windows[hwnd].DrawAlphaBlend(hwnd, hdcMem);
+				
+				// Transfer the off-screen DC to the screen
+				BitBlt(hdc, 0, 0, cxClient, cyClient, hdcMem, 0, 0, SRCCOPY);
+
+				// Free-up the off-screen DC
+				SelectObject(hdcMem, hOld);
+				DeleteObject(hbmMem);
+				DeleteDC (hdcMem);
+
+				EndPaint(hwnd, &ps);
+				return 0;
+			}
+			
+			case WM_DESTROY:
+				windows[hwnd] = null;
+				PostQuitMessage(0);
+				return 0;
+
+			default:
+		}
+
+		return DefWindowProcA(hwnd, message, wParam, lParam);
+	}
+	
+	void DrawAlphaBlend(HWND hWnd, HDC hdcwnd)
+	{
+		HDC hdc;                              // handle of the DC we will create
+		HBITMAP hbitmap;                      // bitmap handle
+		BITMAPINFO bmi;                       // bitmap header
+		VOID*  pvBits;                        // pointer to DIB section
+		ULONG  ulWindowWidth, ulWindowHeight; // window width/height
+		RECT   rt;                            // used for getting window dimensions
+		
+		// get window dimensions
+		GetClientRect(hWnd, &rt);
+
+		// calculate window width/height
+		ulWindowWidth  = rt.right - rt.left;
+		ulWindowHeight = rt.bottom - rt.top;
+
+		// make sure we have at least some window size
+		if (ulWindowWidth < 1 || ulWindowHeight < 1)
+			return;
+
+		// create a DC for our bitmap -- the source DC for GdiAlphaBlend
+		hdc = CreateCompatibleDC(hdcwnd);
+		
+		// setup bitmap info
+		bmi.bmiHeader.biSize        = BITMAPINFOHEADER.sizeof;
+		bmi.bmiHeader.biWidth       = width;
+		bmi.bmiHeader.biHeight      = -height;  // must be inverted so Y axis is at top
+		bmi.bmiHeader.biPlanes      = 1;
+		bmi.bmiHeader.biBitCount    = 32;      // four 8-bit components
+		bmi.bmiHeader.biCompression = BI_RGB;
+		bmi.bmiHeader.biSizeImage   = width * height * 4;
+
+		// create our DIB section and select the bitmap into the dc
+		hbitmap = CreateDIBSection(hdc, &bmi, DIB_RGB_COLORS, &pvBits, null, 0x0);
+		SelectObject(hdc, hbitmap);
+
+		auto area = Geometry(width, height, 0, 0);
+		enum channels = "BGRA";  // win32 uses BGR(A)
+		byte[] arr = (cast(byte*)pvBits)[0 .. (area.width * area.height) * channels.length];
+		image.exportPixels(area, arr, channels);
+
+		//TODO: Rezize image.
+		BitBlt(hdcwnd, 0, 0, width, height, hdc, 0, 0, SRCCOPY);
+
+		DeleteObject(hbitmap);
+		DeleteDC(hdc);
+	}
+}
+
+pragma(lib, "gdi32.lib");
+
+const AC_SRC_OVER  = 0x00;
+const AC_SRC_ALPHA = 0x01;
+const GWLP_USERDATA = -21;
+
+enum DWORD BI_RGB = 0;
+enum UINT DIB_RGB_COLORS = 0;
+
+struct BLENDFUNCTION
+{
+	BYTE BlendOp;
+	BYTE BlendFlags;
+	BYTE SourceConstantAlpha;
+	BYTE AlphaFormat;
+}
+
+struct AlphaBlendType
+{
+	static normal = BLENDFUNCTION(AC_SRC_OVER, 0, 255, AC_SRC_ALPHA);
+}
+
+extern(Windows) BOOL BitBlt(HDC, int, int, int, int, HDC, int, int, DWORD);
+extern(Windows) HBITMAP CreateCompatibleBitmap(HDC, int, int);
+extern(Windows) HBITMAP CreateDIBSection(HDC, const(BITMAPINFO)*, UINT, void**, HANDLE, DWORD);
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