Cairo v. 1.10.2 Headers

[José Roca]

 
Cairo is a 2D graphics library with support for multiple output devices. Currently supported output targets include the X Window System, Quartz, Win32, image buffers, PostScript, PDF, and SVG file output. Experimental backends include OpenGL (through glitz), XCB, BeOS, OS/2, and DirectFB.

Cairo is designed to produce consistent output on all output media while taking advantage of display hardware acceleration when available (eg. through the X Render Extension).

The cairo API provides operations similar to the drawing operators of PostScript and PDF. Operations in cairo including stroking and filling cubic Bézier splines, transforming and compositing translucent images, and antialiased text rendering. All drawing operations can be transformed by any affine transformation (scale, rotation, shear, etc.)

Cairo is implemented as a library written in the C programming language, but bindings are available for several different programming languages.

Cairo is free software and is available to be redistributed and/or modified under the terms of either the GNU Lesser General Public License (LGPL) version 2.1 or the Mozilla Public License (MPL) version 1.1 at your option.

Web Page: http://cairographics.org/

The attached file contains my translation of the GLib headers to PowerBASIC and the needed DLLs (Cairo has dependencies on libpng12-0.dll and zlib1.dll). To use them, add #INCLUDE "cairo_win32.inc" to your program.

The default library name used in the translation is "libcairo-2.dll".

Code Select Expand


#IF NOT %DEF($CAIRO_DLLNAME)
$CAIRO_DLLNAME = "libcairo-2.dll"
#ENDIF


If you use a different version or if you want to rename the .dll, change the value in the constant or define a different value for the constant before #INCLUDE "cairo_win32.inc", e.g.

Code Select Expand


$CAIRO_DLLNAME = "cairo.dll"
#INCLUDE "cairo_win32.inc"


[José Roca]

 
The following example demonstrates how to use Cairo to draw an arc. All the Cairo code has been placed in the RenderScene procedure for easy examination.

SDK Version

Code Select Expand


' ========================================================================================
' Cairo example
' ========================================================================================

' SED_PBWIN
#COMPILE EXE
#DIM ALL
#INCLUDE ONCE "cairo_win32.inc"

' ========================================================================================
' Draw an arc using Cairo.
' ========================================================================================
SUB RenderScene (BYVAL hdc AS DWORD)

   ' // Create a cairo surface we can draw on directly
   LOCAL cairo_surface AS DWORD   ' cairo_surface_t*
   cairo_surface = cairo_win32_surface_create(hdc)
   ' //  create a cairo context with the surface as the target
   LOCAL cairo_image AS DWORD     ' cairo_t*
   cairo_image = cairo_create(cairo_surface)

   ' // Draw the scene
   LOCAL xc, yc, radius, angle1, angle2 AS DOUBLE
   xc = 200.0
   yc = 70.0
   radius = 100.0
   angle1 = 45.0  * (3.141592654 / 180.0)   ' // angles are specified
   angle2 = 180.0 * (3.141592654 / 180.0)   ' // in radians

   cairo_set_line_width(cairo_image, 10.0)
   cairo_arc(cairo_image, xc, yc, radius, angle1, angle2)
   cairo_stroke(cairo_image)

   ' // draw helping lines
   cairo_set_source_rgba(cairo_image, 1, 0.2, 0.2, 0.6)
   cairo_set_line_width(cairo_image, 6.0)

   cairo_arc (cairo_image, xc, yc, 10.0, 0, 2 * 3.141592654)
   cairo_fill(cairo_image)

   cairo_arc(cairo_image, xc, yc, radius, angle1, angle1)
   cairo_line_to(cairo_image, xc, yc)
   cairo_arc(cairo_image, xc, yc, radius, angle2, angle2)
   cairo_line_to(cairo_image, xc, yc)
   cairo_stroke(cairo_image)

   ' // Tear down the cairo object now that we don't need it anymore.
   cairo_destroy(cairo_image)
   cairo_surface_destroy(cairo_surface)

END SUB
' ========================================================================================

' ========================================================================================
' Main
' ========================================================================================
FUNCTION WinMain (BYVAL hInstance AS DWORD, BYVAL hPrevInstance AS DWORD, BYVAL lpszCmdLine AS WSTRINGZ PTR, BYVAL nCmdShow AS LONG) AS LONG

   LOCAL hr AS LONG
   LOCAL hWndMain AS DWORD
   LOCAL hCtl AS DWORD
   LOCAL hFont AS DWORD
   LOCAL wcex AS WndClassEx
   LOCAL szClassName AS ASCIIZ * 80
   LOCAL rc AS RECT
   LOCAL szCaption AS ASCIIZ * 255

   hFont = GetStockObject(%ANSI_VAR_FONT)

   ' Register the window class
   szClassName        = "MyClassName"
   wcex.cbSize        = SIZEOF(wcex)
   wcex.style         = 0 ' %CS_HREDRAW OR %CS_VREDRAW
   wcex.lpfnWndProc   = CODEPTR(WndProc)
   wcex.cbClsExtra    = 0
   wcex.cbWndExtra    = 0
   wcex.hInstance     = hInstance
   wcex.hCursor       = LoadCursor (%NULL, BYVAL %IDC_ARROW)
   wcex.hbrBackground = GetStockObject(%WHITE_BRUSH)
   wcex.lpszMenuName  = %NULL
   wcex.lpszClassName = VARPTR(szClassName)
   wcex.hIcon         = LoadIcon (%NULL, BYVAL %IDI_APPLICATION) ' Sample, if resource icon: LoadIcon(hInst, "APPICON")
   wcex.hIconSm       = LoadIcon (%NULL, BYVAL %IDI_APPLICATION) ' Remember to set small icon too..
   RegisterClassEx wcex

   ' Window caption
   szCaption = "Cairo Example"

   ' Create a window using the registered class
   hWndMain = CreateWindowEx(%WS_EX_CONTROLPARENT, _           ' extended style
                             szClassName, _                    ' window class name
                             szCaption, _                      ' window caption
                             %WS_OVERLAPPEDWINDOW OR _
                             %WS_CLIPCHILDREN, _               ' window style
                             %CW_USEDEFAULT, _                 ' initial x position
                             %CW_USEDEFAULT, _                 ' initial y position
                             %CW_USEDEFAULT, _                 ' initial x nSize
                             %CW_USEDEFAULT, _                 ' initial y nSize
                             %NULL, _                          ' parent window handle
                             0, _                              ' window menu handle
                             hInstance, _                      ' program instance handle
                             BYVAL %NULL)                      ' creation parameters

   ' Show the window
   ShowWindow hWndMain, nCmdShow
   UpdateWindow hWndMain

   ' Message handler loop
   LOCAL uMsg AS tagMsg
   WHILE GetMessage(uMsg, %NULL, 0, 0)
      IF ISFALSE IsDialogMessage(hWndMain, uMsg) THEN
         TranslateMessage uMsg
         DispatchMessage uMsg
      END IF
   WEND

   FUNCTION = uMsg.wParam

END FUNCTION
' ========================================================================================

' ========================================================================================
' Main Window procedure
' ========================================================================================
FUNCTION WndProc (BYVAL hWnd AS DWORD, BYVAL wMsg AS DWORD, BYVAL wParam AS DWORD, BYVAL lParam AS LONG) AS LONG

   LOCAL hDC AS DWORD
   LOCAL ps AS PAINTSTRUCT

   SELECT CASE wMsg

      CASE %WM_COMMAND
         SELECT CASE LO(WORD, wParam)
            CASE %IDCANCEL
               IF HI(WORD, wParam) = %BN_CLICKED THEN
                  SendMessage hWnd, %WM_CLOSE, 0, 0
                  FUNCTION = 0
                  EXIT FUNCTION
               END IF
         END SELECT

      CASE %WM_SYSCOMMAND
         ' Capture this message and send a WM_CLOSE message
         IF (wParam AND &HFFF0) = %SC_CLOSE THEN
            SendMessage hWnd, %WM_CLOSE, 0, 0
            EXIT FUNCTION
         END IF

      CASE %WM_PAINT
         hDC = BeginPaint(hWnd, ps)
         RenderScene hDC
         EndPaint(hWnd, ps)

      CASE %WM_DESTROY
         PostQuitMessage 0
         EXIT FUNCTION

   END SELECT

   FUNCTION = DefWindowProc(hWnd, wMsg, wParam, lParam)

END FUNCTION
' ========================================================================================


CWindow Version

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#COMPILE EXE
#DIM ALL
%UNICODE = 1

' // Include files for external files
#INCLUDE ONCE "CWindow.inc"
#INCLUDE ONCE "cairo_win32.inc"

' ========================================================================================
' Main
' ========================================================================================
FUNCTION WinMain (BYVAL hInstance AS DWORD, BYVAL hPrevInstance AS DWORD, BYVAL lpszCmdLine AS WSTRINGZ PTR, BYVAL nCmdShow AS LONG) AS LONG

   ' // Create an instance of the class
   LOCAL pWindow AS IWindow
   pWindow = CLASS "CWindow"
   IF ISNOTHING(pWindow) THEN EXIT FUNCTION

   ' // Create the main window
   ' // Note: CW_USEDEFAULT is used as the default value When passing 0's as the width and height
   pWindow.CreateWindow(%NULL, "Cairo Example", 0, 0, 0, 0, -1, -1, CODEPTR(WindowProc))
   ' // Change the brush for the background
   pWindow.Brush = GetStockObject(%WHITE_BRUSH)

   ' // Center the window
   pWindow.CenterWindow

   ' // Default message pump (you can replace it with your own)
   pWindow.DoEvents(nCmdShow)

END FUNCTION
' ========================================================================================

' ========================================================================================
' Main callback function.
' ========================================================================================
FUNCTION WindowProc (BYVAL hwnd AS DWORD, BYVAL uMsg AS DWORD, BYVAL wParam AS DWORD, BYVAL lParam AS LONG) AS LONG

   LOCAL hDC AS DWORD
   LOCAL ps AS PAINTSTRUCT

   ' // Process window mesages
   SELECT CASE uMsg

      CASE %WM_COMMAND
         SELECT CASE LO(WORD, wParam)
            CASE %IDCANCEL
               ' // If the Escape key has been pressed...
               IF HI(WORD, wParam) = %BN_CLICKED THEN
                  ' // ... close the application by sending a WM_CLOSE message
                  SendMessage hwnd, %WM_CLOSE, 0, 0
                  EXIT FUNCTION
               END IF
         END SELECT

      CASE %WM_PAINT
         hDC = BeginPaint(hWnd, ps)
         RenderScene hDC
         EndPaint(hWnd, ps)

      CASE %WM_DESTROY
         ' // End the application
         PostQuitMessage 0
         EXIT FUNCTION

   END SELECT

   ' // Pass unprocessed messages to Windows
   FUNCTION = DefWindowProc(hwnd, uMsg, wParam, lParam)

END FUNCTION
' ========================================================================================

' ========================================================================================
' Draw an arc using Cairo.
' ========================================================================================
SUB RenderScene (BYVAL hdc AS DWORD)

   ' // Create a cairo surface we can draw on directly
   LOCAL cairo_surface AS DWORD   ' cairo_surface_t*
   cairo_surface = cairo_win32_surface_create(hdc)
   ' //  create a cairo context with the surface as the target
   LOCAL cairo_image AS DWORD     ' cairo_t*
   cairo_image = cairo_create(cairo_surface)

   ' // Draw the scene
   LOCAL xc, yc, radius, angle1, angle2 AS DOUBLE
   xc = 200.0
   yc = 70.0
   radius = 100.0
   angle1 = 45.0  * (3.141592654 / 180.0)   ' // angles are specified
   angle2 = 180.0 * (3.141592654 / 180.0)   ' // in radians

   cairo_set_line_width(cairo_image, 10.0)
   cairo_arc(cairo_image, xc, yc, radius, angle1, angle2)
   cairo_stroke(cairo_image)

   ' // draw helping lines
   cairo_set_source_rgba(cairo_image, 1, 0.2, 0.2, 0.6)
   cairo_set_line_width(cairo_image, 6.0)

   cairo_arc (cairo_image, xc, yc, 10.0, 0, 2 * 3.141592654)
   cairo_fill(cairo_image)

   cairo_arc(cairo_image, xc, yc, radius, angle1, angle1)
   cairo_line_to(cairo_image, xc, yc)
   cairo_arc(cairo_image, xc, yc, radius, angle2, angle2)
   cairo_line_to(cairo_image, xc, yc)
   cairo_stroke(cairo_image)

   ' // Tear down the cairo object now that we don't need it anymore.
   cairo_destroy(cairo_image)
   cairo_surface_destroy(cairo_surface)

END SUB
' ========================================================================================


[José Roca]

 
Same as above, but using double buffering. All the code to create and render the double buffer has been placed under the WM_PAINT message.

SDK Version

Code Select Expand


' ========================================================================================
' Cairo example with double buffering
' ========================================================================================

' SED_PBWIN
#COMPILE EXE
#DIM ALL
#INCLUDE "cairo_win32.inc"

' ========================================================================================
' Draw an arc using Cairo.
' ========================================================================================
SUB RenderScene (BYVAL hdc AS DWORD)

   ' // Create a cairo surface we can draw on directly
   LOCAL cairo_surface AS DWORD   ' cairo_surface_t*
   cairo_surface = cairo_win32_surface_create(hdc)
   ' // Create a cairo context with the surface as the target
   LOCAL cairo_image AS DWORD     ' cairo_t*
   cairo_image = cairo_create(cairo_surface)

   ' // Draw the scene
   LOCAL xc, yc, radius, angle1, angle2 AS DOUBLE
   xc = 200.0
   yc = 70.0
   radius = 100.0
   angle1 = 45.0  * (3.141592654 / 180.0)   ' // angles are specified
   angle2 = 180.0 * (3.141592654 / 180.0)   ' // in radians

   cairo_set_line_width(cairo_image, 10.0)
   cairo_arc(cairo_image, xc, yc, radius, angle1, angle2)
   cairo_stroke(cairo_image)

   ' // Draw helping lines
   cairo_set_source_rgba(cairo_image, 1, 0.2, 0.2, 0.6)
   cairo_set_line_width(cairo_image, 6.0)

   cairo_arc (cairo_image, xc, yc, 10.0, 0, 2 * 3.141592654)
   cairo_fill(cairo_image)

   cairo_arc(cairo_image, xc, yc, radius, angle1, angle1)
   cairo_line_to(cairo_image, xc, yc)
   cairo_arc(cairo_image, xc, yc, radius, angle2, angle2)
   cairo_line_to(cairo_image, xc, yc)
   cairo_stroke(cairo_image)

   ' // Tear down the cairo object now that we don't need it anymore.
   cairo_destroy(cairo_image)
   cairo_surface_destroy(cairo_surface)

END SUB
' ========================================================================================

' ========================================================================================
' Main
' ========================================================================================
FUNCTION WinMain (BYVAL hInstance AS DWORD, BYVAL hPrevInstance AS DWORD, BYVAL lpszCmdLine AS WSTRINGZ PTR, BYVAL nCmdShow AS LONG) AS LONG

   LOCAL hr AS LONG
   LOCAL hWndMain AS DWORD
   LOCAL hCtl AS DWORD
   LOCAL hFont AS DWORD
   LOCAL wcex AS WndClassEx
   LOCAL szClassName AS ASCIIZ * 80
   LOCAL rc AS RECT
   LOCAL szCaption AS ASCIIZ * 255

   hFont = GetStockObject(%ANSI_VAR_FONT)

   ' Register the window class
   szClassName        = "MyClassName"
   wcex.cbSize        = SIZEOF(wcex)
   wcex.style         = 0 ' %CS_HREDRAW OR %CS_VREDRAW
   wcex.lpfnWndProc   = CODEPTR(WndProc)
   wcex.cbClsExtra    = 0
   wcex.cbWndExtra    = 0
   wcex.hInstance     = hInstance
   wcex.hCursor       = LoadCursor (%NULL, BYVAL %IDC_ARROW)
   wcex.hbrBackground = GetStockObject(%WHITE_BRUSH)
   wcex.lpszMenuName  = %NULL
   wcex.lpszClassName = VARPTR(szClassName)
   wcex.hIcon         = LoadIcon (%NULL, BYVAL %IDI_APPLICATION) ' Sample, if resource icon: LoadIcon(hInst, "APPICON")
   wcex.hIconSm       = LoadIcon (%NULL, BYVAL %IDI_APPLICATION) ' Remember to set small icon too..
   RegisterClassEx wcex

   ' Window caption
   szCaption = "Cairo Example - Double Buffering"

   ' Create a window using the registered class
   hWndMain = CreateWindowEx(%WS_EX_CONTROLPARENT, _           ' extended style
                             szClassName, _                    ' window class name
                             szCaption, _                      ' window caption
                             %WS_OVERLAPPEDWINDOW OR _
                             %WS_CLIPCHILDREN, _               ' window style
                             %CW_USEDEFAULT, _                 ' initial x position
                             %CW_USEDEFAULT, _                 ' initial y position
                             %CW_USEDEFAULT, _                 ' initial x nSize
                             %CW_USEDEFAULT, _                 ' initial y nSize
                             %NULL, _                          ' parent window handle
                             0, _                              ' window menu handle
                             hInstance, _                      ' program instance handle
                             BYVAL %NULL)                      ' creation parameters

   ' Show the window
   ShowWindow hWndMain, nCmdShow
   UpdateWindow hWndMain

   ' Message handler loop
   LOCAL uMsg AS tagMsg
   WHILE GetMessage(uMsg, %NULL, 0, 0)
      IF ISFALSE IsDialogMessage(hWndMain, uMsg) THEN
         TranslateMessage uMsg
         DispatchMessage uMsg
      END IF
   WEND

   FUNCTION = uMsg.wParam

END FUNCTION
' ========================================================================================

' ========================================================================================
' Main Window procedure
' ========================================================================================
FUNCTION WndProc (BYVAL hWnd AS DWORD, BYVAL wMsg AS DWORD, BYVAL wParam AS DWORD, BYVAL lParam AS LONG) AS LONG

   LOCAL hDC AS DWORD
   LOCAL ps AS PAINTSTRUCT

   SELECT CASE wMsg

      CASE %WM_COMMAND
         SELECT CASE LO(WORD, wParam)
            CASE %IDCANCEL
               IF HI(WORD, wParam) = %BN_CLICKED THEN
                  SendMessage hWnd, %WM_CLOSE, 0, 0
                  FUNCTION = 0
                  EXIT FUNCTION
               END IF
         END SELECT

      CASE %WM_SYSCOMMAND
         ' Capture this message and send a WM_CLOSE message
         IF (wParam AND &HFFF0) = %SC_CLOSE THEN
            SendMessage hWnd, %WM_CLOSE, 0, 0
            EXIT FUNCTION
         END IF

      CASE %WM_PAINT
         hDC = BeginPaint(hWnd, ps)
            ' // Get the client coordinates
            LOCAL rc AS RECT
            GetClientRect(hWnd, rc)
            ' // Create a double buffer for blitting to the screen to prevent screen flicker.
            LOCAL hdcBuffer AS DWORD
            hdcBuffer = CreateCompatibleDC(hdc)
            LOCAL hbmpBuffer AS DWORD
            hbmpBuffer = CreateCompatibleBitmap(hdc, rc.nRight - rc.nLeft, rc.nBottom - rc.nTop)
            SelectObject(hdcBuffer, hbmpBuffer)
            ' // Clear it using a white brush
            LOCAL hBrush AS DWORD
            LOCAL hOldDc AS DWORD
            hBrush = CreateSolidBrush(%WHITE)
            hOldDc = SelectObject(hdcBuffer, hBrush)
            FillRect hdcBuffer, rc, hBrush
            DeleteObject hBrush
            IF hOldDc THEN SelectObject hdcBuffer, hOldDc
            ' // Draw the scene in the a cairo surface
            RenderScene hdcBuffer
            ' // Now blit the object to the screen
            BitBlt(hdc, 0, 0, rc.nRight - rc.nLeft, rc.nBottom - rc.nTop, hdcBuffer, 0, 0, %SRCCOPY)
            ' // Release resources
            DeleteDC(hdcbuffer)
            DeleteObject(hbmpBuffer)
         EndPaint(hWnd, ps)

      CASE %WM_DESTROY
         PostQuitMessage 0
         EXIT FUNCTION

   END SELECT

   FUNCTION = DefWindowProc(hWnd, wMsg, wParam, lParam)

END FUNCTION
' ========================================================================================


CWindow Version

Code Select Expand


#COMPILE EXE
#DIM ALL
%UNICODE = 1

' // Include files for external files
#INCLUDE ONCE "CWindow.inc"
#INCLUDE ONCE "cairo_win32.inc"

' ========================================================================================
' Main
' ========================================================================================
FUNCTION WinMain (BYVAL hInstance AS DWORD, BYVAL hPrevInstance AS DWORD, BYVAL lpszCmdLine AS WSTRINGZ PTR, BYVAL nCmdShow AS LONG) AS LONG

   ' // Create an instance of the class
   LOCAL pWindow AS IWindow
   pWindow = CLASS "CWindow"
   IF ISNOTHING(pWindow) THEN EXIT FUNCTION

   ' // Create the main window
   ' // Note: CW_USEDEFAULT is used as the default value When passing 0's as the width and height
   pWindow.CreateWindow(%NULL, "Cairo Example - Double Buffering", 0, 0, 0, 0, -1, -1, CODEPTR(WindowProc))
   ' // Change the brush for the background
   pWindow.Brush = GetStockObject(%WHITE_BRUSH)

   ' // Center the window
   pWindow.CenterWindow

   ' // Default message pump (you can replace it with your own)
   pWindow.DoEvents(nCmdShow)

END FUNCTION
' ========================================================================================

' ========================================================================================
' Main callback function.
' ========================================================================================
FUNCTION WindowProc (BYVAL hwnd AS DWORD, BYVAL uMsg AS DWORD, BYVAL wParam AS DWORD, BYVAL lParam AS LONG) AS LONG

   LOCAL hDC AS DWORD
   LOCAL ps AS PAINTSTRUCT

   ' // Process window mesages
   SELECT CASE uMsg

      CASE %WM_COMMAND
         SELECT CASE LO(WORD, wParam)
            CASE %IDCANCEL
               ' // If the Escape key has been pressed...
               IF HI(WORD, wParam) = %BN_CLICKED THEN
                  ' // ... close the application by sending a WM_CLOSE message
                  SendMessage hwnd, %WM_CLOSE, 0, 0
                  EXIT FUNCTION
               END IF
         END SELECT

      CASE %WM_PAINT
         hDC = BeginPaint(hWnd, ps)
            ' // Get the client coordinates
            LOCAL rc AS RECT
            GetClientRect(hWnd, rc)
            ' // Create a double buffer for blitting to the screen to prevent screen flicker.
            LOCAL hdcBuffer AS DWORD
            hdcBuffer = CreateCompatibleDC(hdc)
            LOCAL hbmpBuffer AS DWORD
            hbmpBuffer = CreateCompatibleBitmap(hdc, rc.nRight - rc.nLeft, rc.nBottom - rc.nTop)
            SelectObject(hdcBuffer, hbmpBuffer)
            ' // Clear it using a white brush
            LOCAL hBrush AS DWORD
            LOCAL hOldDc AS DWORD
            hBrush = CreateSolidBrush(%WHITE)
            hOldDc = SelectObject(hdcBuffer, hBrush)
            FillRect hdcBuffer, rc, hBrush
            DeleteObject hBrush
            IF hOldDc THEN SelectObject hdcBuffer, hOldDc
            ' // Draw the scene in the a cairo surface
            RenderScene hdcBuffer
            ' // Now blit the object to the screen
            BitBlt(hdc, 0, 0, rc.nRight - rc.nLeft, rc.nBottom - rc.nTop, hdcBuffer, 0, 0, %SRCCOPY)
            ' // Release resources
            DeleteDC(hdcbuffer)
            DeleteObject(hbmpBuffer)
         EndPaint(hWnd, ps)

      CASE %WM_DESTROY
         ' // End the application
         PostQuitMessage 0
         EXIT FUNCTION

   END SELECT

   ' // Pass unprocessed messages to Windows
   FUNCTION = DefWindowProc(hwnd, uMsg, wParam, lParam)

END FUNCTION
' ========================================================================================

' ========================================================================================
' Draw an arc using Cairo.
' ========================================================================================
SUB RenderScene (BYVAL hdc AS DWORD)

   ' // Create a cairo surface we can draw on directly
   LOCAL cairo_surface AS DWORD   ' cairo_surface_t*
   cairo_surface = cairo_win32_surface_create(hdc)
   ' // Create a cairo context with the surface as the target
   LOCAL cairo_image AS DWORD     ' cairo_t*
   cairo_image = cairo_create(cairo_surface)

   ' // Draw the scene
   LOCAL xc, yc, radius, angle1, angle2 AS DOUBLE
   xc = 200.0
   yc = 70.0
   radius = 100.0
   angle1 = 45.0  * (3.141592654 / 180.0)   ' // angles are specified
   angle2 = 180.0 * (3.141592654 / 180.0)   ' // in radians

   cairo_set_line_width(cairo_image, 10.0)
   cairo_arc(cairo_image, xc, yc, radius, angle1, angle2)
   cairo_stroke(cairo_image)

   ' // Draw helping lines
   cairo_set_source_rgba(cairo_image, 1, 0.2, 0.2, 0.6)
   cairo_set_line_width(cairo_image, 6.0)

   cairo_arc (cairo_image, xc, yc, 10.0, 0, 2 * 3.141592654)
   cairo_fill(cairo_image)

   cairo_arc(cairo_image, xc, yc, radius, angle1, angle1)
   cairo_line_to(cairo_image, xc, yc)
   cairo_arc(cairo_image, xc, yc, radius, angle2, angle2)
   cairo_line_to(cairo_image, xc, yc)
   cairo_stroke(cairo_image)

   ' // Tear down the cairo object now that we don't need it anymore.
   cairo_destroy(cairo_image)
   cairo_surface_destroy(cairo_surface)

END SUB
' ========================================================================================


[José Roca]

 
A minimal program using Cairo. Draws an outlined "Hello, World", and saves it as a .png file.

Code Select Expand


' ========================================================================================
' A minimal program using Cairo.
' Draws an outlined "Hello, World", and saves it as a .png file
' ========================================================================================

' SED_PBWIN
#COMPILE EXE
#DIM ALL
#INCLUDE "cairo.inc"

' ========================================================================================
' Main
' ========================================================================================
FUNCTION WINMAIN (BYVAL hInstance AS DWORD, BYVAL hPrevInstance AS DWORD, BYVAL lpszCmdLine AS WSTRINGZ PTR, BYVAL nCmdShow AS LONG) AS LONG

   LOCAL cairo_surface AS DWORD
   cairo_surface = cairo_image_surface_create (%CAIRO_FORMAT_ARGB32, 240, 80)
   LOCAL cairo_image AS DWORD
   cairo_image = cairo_create(cairo_surface)

   cairo_select_font_face(cairo_image, "serif", %CAIRO_FONT_SLANT_NORMAL, %CAIRO_FONT_WEIGHT_BOLD)
   cairo_set_font_size(cairo_image, 32.0)
   cairo_set_source_rgb(cairo_image, 0.0, 0.0, 1.0)
   cairo_move_to(cairo_image, 10.0, 50.0)
   cairo_show_text(cairo_image, "Hello, world")

   cairo_destroy(cairo_image)
   cairo_surface_write_to_png(cairo_surface, "hello.png")
   cairo_surface_destroy(cairo_surface)

END FUNCTION
' ========================================================================================


[José Roca]

 
Gradient example.

SDK Version

Code Select Expand


' ========================================================================================
' Cairo example: Gradient
' ========================================================================================

' SED_PBWIN
#COMPILE EXE
#DIM ALL
#INCLUDE "cairo_win32.inc"

' ========================================================================================
' Render the scene
' ========================================================================================
SUB RenderScene (BYVAL hdc AS DWORD)

   ' // Create a cairo surface we can draw on directly
   LOCAL cairo_surface AS DWORD   ' cairo_surface_t*
   cairo_surface = cairo_win32_surface_create(hdc)

   ' // Create a cairo context with the surface as the target
   LOCAL cairo_image AS DWORD     ' cairo_t*
   cairo_image = cairo_create(cairo_surface)

   ' // Draw the scene
   LOCAL pat AS DWORD   ' cairo_pattern_t

   pat = cairo_pattern_create_linear(0.0, 0.0,  0.0, 256.0)
   cairo_pattern_add_color_stop_rgba(pat, 1, 0, 0, 0, 1)
   cairo_pattern_add_color_stop_rgba(pat, 0, 1, 1, 1, 1)
   cairo_rectangle(cairo_image, 0, 0, 256, 256)
   cairo_set_source(cairo_image, pat)
   cairo_fill(cairo_image)
   cairo_pattern_destroy(pat)

   pat = cairo_pattern_create_radial(115.2, 102.4, 25.6, 102.4, 102.4, 128.0)
   cairo_pattern_add_color_stop_rgba(pat, 0, 1, 1, 1, 1)
   cairo_pattern_add_color_stop_rgba(pat, 1, 0, 0, 0, 1)
   cairo_set_source(cairo_image, pat)
   cairo_arc(cairo_image, 128.0, 128.0, 76.8, 0, 2 * 3.141592654)
   cairo_fill(cairo_image)
   cairo_pattern_destroy(pat)

   ' // Tear down the cairo object now that we don't need it anymore.
   cairo_destroy(cairo_image)
   cairo_surface_destroy(cairo_surface)

END SUB
' ========================================================================================

' ========================================================================================
' Main
' ========================================================================================
FUNCTION WinMain (BYVAL hInstance AS DWORD, BYVAL hPrevInstance AS DWORD, BYVAL lpszCmdLine AS WSTRINGZ PTR, BYVAL nCmdShow AS LONG) AS LONG

   LOCAL hr AS LONG
   LOCAL hWndMain AS DWORD
   LOCAL hCtl AS DWORD
   LOCAL hFont AS DWORD
   LOCAL wcex AS WndClassEx
   LOCAL szClassName AS ASCIIZ * 80
   LOCAL rc AS RECT
   LOCAL szCaption AS ASCIIZ * 255

   hFont = GetStockObject(%ANSI_VAR_FONT)

   ' Register the window class
   szClassName        = "MyClassName"
   wcex.cbSize        = SIZEOF(wcex)
   wcex.style         = 0 ' %CS_HREDRAW OR %CS_VREDRAW
   wcex.lpfnWndProc   = CODEPTR(WndProc)
   wcex.cbClsExtra    = 0
   wcex.cbWndExtra    = 0
   wcex.hInstance     = hInstance
   wcex.hCursor       = LoadCursor (%NULL, BYVAL %IDC_ARROW)
   wcex.hbrBackground = GetStockObject(%WHITE_BRUSH)
   wcex.lpszMenuName  = %NULL
   wcex.lpszClassName = VARPTR(szClassName)
   wcex.hIcon         = LoadIcon (%NULL, BYVAL %IDI_APPLICATION) ' Sample, if resource icon: LoadIcon(hInst, "APPICON")
   wcex.hIconSm       = LoadIcon (%NULL, BYVAL %IDI_APPLICATION) ' Remember to set small icon too..
   RegisterClassEx wcex

   ' Window caption
   szCaption = "Cairo Example: Gradient"

   ' Create a window using the registered class
   hWndMain = CreateWindowEx(%WS_EX_CONTROLPARENT, _           ' extended style
                             szClassName, _                    ' window class name
                             szCaption, _                      ' window caption
                             %WS_OVERLAPPEDWINDOW OR _
                             %WS_CLIPCHILDREN, _               ' window style
                             %CW_USEDEFAULT, _                 ' initial x position
                             %CW_USEDEFAULT, _                 ' initial y position
                             %CW_USEDEFAULT, _                 ' initial x nSize
                             %CW_USEDEFAULT, _                 ' initial y nSize
                             %NULL, _                          ' parent window handle
                             0, _                              ' window menu handle
                             hInstance, _                      ' program instance handle
                             BYVAL %NULL)                      ' creation parameters

   ' Show the window
   ShowWindow hWndMain, nCmdShow
   UpdateWindow hWndMain

   ' Message handler loop
   LOCAL uMsg AS tagMsg
   WHILE GetMessage(uMsg, %NULL, 0, 0)
      IF ISFALSE IsDialogMessage(hWndMain, uMsg) THEN
         TranslateMessage uMsg
         DispatchMessage uMsg
      END IF
   WEND

   FUNCTION = uMsg.wParam

END FUNCTION
' ========================================================================================

' ========================================================================================
' Main Window procedure
' ========================================================================================
FUNCTION WndProc (BYVAL hWnd AS DWORD, BYVAL wMsg AS DWORD, BYVAL wParam AS DWORD, BYVAL lParam AS LONG) AS LONG

   LOCAL hDC AS DWORD
   LOCAL ps AS PAINTSTRUCT

   SELECT CASE wMsg

      CASE %WM_COMMAND
         SELECT CASE LO(WORD, wParam)
            CASE %IDCANCEL
               IF HI(WORD, wParam) = %BN_CLICKED THEN
                  SendMessage hWnd, %WM_CLOSE, 0, 0
                  FUNCTION = 0
                  EXIT FUNCTION
               END IF
         END SELECT

      CASE %WM_SYSCOMMAND
         ' Capture this message and send a WM_CLOSE message
         IF (wParam AND &HFFF0) = %SC_CLOSE THEN
            SendMessage hWnd, %WM_CLOSE, 0, 0
            EXIT FUNCTION
         END IF

      CASE %WM_PAINT
         hDC = BeginPaint(hWnd, ps)
         RenderScene hDC
         EndPaint(hWnd, ps)

      CASE %WM_DESTROY
         PostQuitMessage 0
         EXIT FUNCTION

   END SELECT

   FUNCTION = DefWindowProc(hWnd, wMsg, wParam, lParam)

END FUNCTION
' ========================================================================================


CWindow Version

Code Select Expand


#COMPILE EXE
#DIM ALL
%UNICODE = 1

' // Include files for external files
#INCLUDE ONCE "CWindow.inc"
#INCLUDE ONCE "cairo_win32.inc"

' ========================================================================================
' Main
' ========================================================================================
FUNCTION WinMain (BYVAL hInstance AS DWORD, BYVAL hPrevInstance AS DWORD, BYVAL lpszCmdLine AS WSTRINGZ PTR, BYVAL nCmdShow AS LONG) AS LONG

   ' // Create an instance of the class
   LOCAL pWindow AS IWindow
   pWindow = CLASS "CWindow"
   IF ISNOTHING(pWindow) THEN EXIT FUNCTION

   ' // Create the main window
   ' // Note: CW_USEDEFAULT is used as the default value When passing 0's as the width and height
   pWindow.CreateWindow(%NULL, "Cairo Example: Gradient", 0, 0, 0, 0, -1, -1, CODEPTR(WindowProc))
   ' // Change the brush for the background
   pWindow.Brush = GetStockObject(%WHITE_BRUSH)

   ' // Center the window
   pWindow.CenterWindow

   ' // Default message pump (you can replace it with your own)
   pWindow.DoEvents(nCmdShow)

END FUNCTION
' ========================================================================================

' ========================================================================================
' Main callback function.
' ========================================================================================
FUNCTION WindowProc (BYVAL hwnd AS DWORD, BYVAL uMsg AS DWORD, BYVAL wParam AS DWORD, BYVAL lParam AS LONG) AS LONG

   LOCAL hDC AS DWORD
   LOCAL ps AS PAINTSTRUCT

   ' // Process window mesages
   SELECT CASE uMsg

      CASE %WM_COMMAND
         SELECT CASE LO(WORD, wParam)
            CASE %IDCANCEL
               ' // If the Escape key has been pressed...
               IF HI(WORD, wParam) = %BN_CLICKED THEN
                  ' // ... close the application by sending a WM_CLOSE message
                  SendMessage hwnd, %WM_CLOSE, 0, 0
                  EXIT FUNCTION
               END IF
         END SELECT

      CASE %WM_PAINT
         hDC = BeginPaint(hWnd, ps)
         RenderScene hDC
         EndPaint(hWnd, ps)

      CASE %WM_DESTROY
         ' // End the application
         PostQuitMessage 0
         EXIT FUNCTION

   END SELECT

   ' // Pass unprocessed messages to Windows
   FUNCTION = DefWindowProc(hwnd, uMsg, wParam, lParam)

END FUNCTION
' ========================================================================================

' ========================================================================================
' Render the scene
' ========================================================================================
SUB RenderScene (BYVAL hdc AS DWORD)

   ' // Create a cairo surface we can draw on directly
   LOCAL cairo_surface AS DWORD   ' cairo_surface_t*
   cairo_surface = cairo_win32_surface_create(hdc)

   ' // Create a cairo context with the surface as the target
   LOCAL cairo_image AS DWORD     ' cairo_t*
   cairo_image = cairo_create(cairo_surface)

   ' // Draw the scene
   LOCAL pat AS DWORD   ' cairo_pattern_t

   pat = cairo_pattern_create_linear(0.0, 0.0,  0.0, 256.0)
   cairo_pattern_add_color_stop_rgba(pat, 1, 0, 0, 0, 1)
   cairo_pattern_add_color_stop_rgba(pat, 0, 1, 1, 1, 1)
   cairo_rectangle(cairo_image, 0, 0, 256, 256)
   cairo_set_source(cairo_image, pat)
   cairo_fill(cairo_image)
   cairo_pattern_destroy(pat)

   pat = cairo_pattern_create_radial(115.2, 102.4, 25.6, 102.4, 102.4, 128.0)
   cairo_pattern_add_color_stop_rgba(pat, 0, 1, 1, 1, 1)
   cairo_pattern_add_color_stop_rgba(pat, 1, 0, 0, 0, 1)
   cairo_set_source(cairo_image, pat)
   cairo_arc(cairo_image, 128.0, 128.0, 76.8, 0, 2 * 3.141592654)
   cairo_fill(cairo_image)
   cairo_pattern_destroy(pat)

   ' // Tear down the cairo object now that we don't need it anymore.
   cairo_destroy(cairo_image)
   cairo_surface_destroy(cairo_surface)

END SUB
' ========================================================================================