Rewrite all fl_XXX_offscreen() functions so they use an Fl_Image_Surface object.

These functions become therefore platform-independent.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3-porting@11241 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

8 files changed, 139 insertions, 145 deletions

diff --git a/src/Fl_Copy_Surface.cxx b/src/Fl_Copy_Surface.cxx
index 1484504b6..8076325bc 100644
--- a/src/Fl_Copy_Surface.cxx
+++ b/src/Fl_Copy_Surface.cxx
@@ -77,6 +77,7 @@ Fl_Copy_Surface::Fl_Copy_Surface(int w, int h) :  Fl_Widget_Surface(NULL)
   Fl::first_window()->make_current();
   oldwindow = fl_xid(Fl::first_window());
   xid = fl_create_offscreen(w,h);
+  _ss = NULL;
   Fl_Surface_Device *present_surface = Fl_Surface_Device::surface();
   set_current();
   fl_color(FL_WHITE);
@@ -128,7 +129,7 @@ void Fl_Copy_Surface::set_current()
 #  pragma message "FL_PORTING: implement Fl_Copy_Surface::set_current"
 #else
   fl_window=xid;
-  _ss = Fl_Surface_Device::surface();
+  if (!_ss) _ss = Fl_Surface_Device::surface();
   Fl_Surface_Device::set_current();
   fl_push_no_clip();
 #endif
diff --git a/src/Fl_Double_Window.cxx b/src/Fl_Double_Window.cxx
index 975c23dd4..243101f96 100644
--- a/src/Fl_Double_Window.cxx
+++ b/src/Fl_Double_Window.cxx
@@ -81,20 +81,6 @@ void Fl_Double_Window::show() {
 }
 
 
-/** \addtogroup fl_drawings
- @{
- */
-/** Copy a rectangular area of the given offscreen buffer into the current drawing destination.
- \param x,y	position where to draw the copied rectangle
- \param w,h	size of the copied rectangle
- \param pixmap  offscreen buffer containing the rectangle to copy
- \param srcx,srcy origin in offscreen buffer of rectangle to copy
- */
-void fl_copy_offscreen(int x, int y, int w, int h, Fl_Offscreen pixmap, int srcx, int srcy) {
-  fl_graphics_driver->copy_offscreen(x, y, w, h, pixmap, srcx, srcy);
-}
-/** @} */
-
 /** see fl_copy_offscreen() */
 void Fl_Graphics_Driver::copy_offscreen(int x, int y, int w, int h, Fl_Offscreen pixmap, int srcx, int srcy)
 {
@@ -209,7 +195,7 @@ void Fl_Double_Window::flush(int eraseoverlay) {
   // on Irix (at least) it is faster to reduce the area copied to
   // the current clip region:
   int X,Y,W,H; fl_clip_box(0,0,w(),h(),X,Y,W,H);
-  if (myi->other_xid) fl_copy_offscreen(X, Y, W, H, myi->other_xid, X, Y);
+  if (myi->other_xid) fl_graphics_driver->copy_offscreen(X, Y, W, H, myi->other_xid, X, Y);
 }
 
 void Fl_Double_Window::resize(int X,int Y,int W,int H) {
diff --git a/src/Fl_Image_Surface.cxx b/src/Fl_Image_Surface.cxx
index e8642c2bf..747b051af 100644
--- a/src/Fl_Image_Surface.cxx
+++ b/src/Fl_Image_Surface.cxx
@@ -40,38 +40,56 @@
 
 /** Constructor with optional high resolution.
  \param w and \param h give the size in pixels of the resulting image.
- \param highres if non-zero, the surface pixel size is twice as high and wide as w and h,
+ \param high_res if non-zero, the surface pixel size is twice as high and wide as w and h,
  which is useful to draw it later on a high resolution display (e.g., retina display).
  This is implemented for the Mac OS platform only.
  If \p highres is non-zero, use Fl_Image_Surface::highres_image() to get the image data.
  \version 1.3.4 (1.3.3 without the highres parameter)
  */
-Fl_Image_Surface::Fl_Image_Surface(int w, int h, int highres) : Fl_Widget_Surface(NULL) {
+Fl_Image_Surface::Fl_Image_Surface(int w, int h, int high_res) : Fl_Widget_Surface(NULL) {
+  initialize_(NULL, w, h, high_res);
+}
+
+void Fl_Image_Surface::initialize_(Fl_Offscreen pixmap, int w, int h, int high_res) {
   width = w;
   height = h;
+  previous = 0;
 #ifdef __APPLE__ // PORTME: platform image surface
-  offscreen = fl_create_offscreen(highres ? 2*w : w, highres ? 2*h : h);
+  int W = high_res ? 2*w : w;
+  int H = high_res ? 2*h : h;
+  CGColorSpaceRef lut = CGColorSpaceCreateDeviceRGB();
+  offscreen = CGBitmapContextCreate(calloc(W*H,4), W, H, 8, W*4, lut, kCGImageAlphaPremultipliedLast);
+  CGColorSpaceRelease(lut);
   driver(new Fl_Quartz_Graphics_Driver);
-  if (highres) {
+  CGContextTranslateCTM(offscreen, -0.5, 0.5); // as when drawing to a window
+  if (high_res) {
     CGContextScaleCTM(offscreen, 2, 2);
   }
   CGContextSetShouldAntialias(offscreen, false);
   CGContextSaveGState(offscreen);
   CGContextTranslateCTM(offscreen, 0, height);
   CGContextScaleCTM(offscreen, 1.0f, -1.0f);
-  CGContextSetRGBFillColor(offscreen, 1, 1, 1, 1);
+  CGContextSetRGBFillColor(offscreen, 1, 1, 1, 0);
   CGContextFillRect(offscreen, CGRectMake(0,0,w,h));
 #elif defined(WIN32)
-  offscreen = fl_create_offscreen(w, h);
+  offscreen = CreateCompatibleBitmap( (fl_graphics_driver->gc() ? (HDC)fl_graphics_driver->gc() : fl_GetDC(0) ) , w, h);
   driver(new Fl_Translated_GDI_Graphics_Driver);
+  _sgc = NULL;
 #elif defined(FL_PORTING)
 #  pragma message "FL_PORTING: implement Fl_Image_Surface"
 #else
-  offscreen = fl_create_offscreen(w, h);
+  offscreen = pixmap ? pixmap : XCreatePixmap(fl_display, RootWindow(fl_display, fl_screen), w, h, fl_visual->depth);
   driver(new Fl_Translated_Xlib_Graphics_Driver());
 #endif
 }
 
+#if USE_X11
+// private constructor for X11 only
+Fl_Image_Surface::Fl_Image_Surface(Fl_Offscreen pixmap, int w, int h) : Fl_Widget_Surface(NULL) {
+    initialize_(pixmap, w, h, 0);
+  }
+#endif
+
 /** The destructor.
  */
 Fl_Image_Surface::~Fl_Image_Surface() {
@@ -80,11 +98,11 @@ Fl_Image_Surface::~Fl_Image_Surface() {
   free(data);
   CGContextRelease((CGContextRef)offscreen);
 #elif defined(WIN32)
-  fl_delete_offscreen(offscreen);
+  DeleteObject(offscreen);
 #elif defined(FL_PORTING)
 #  pragma message "FL_PORTING: implement Fl_Image_Surface"
 #else
-  fl_delete_offscreen(offscreen);
+  XFreePixmap(fl_display, offscreen);
 #endif
 }
 
@@ -100,24 +118,16 @@ Fl_RGB_Image* Fl_Image_Surface::image()
   CGContextFlush(offscreen);
   W = CGBitmapContextGetWidth(offscreen);
   H = CGBitmapContextGetHeight(offscreen);
-  Fl_X::set_high_resolution(0);
   data = fl_read_image(NULL, 0, 0, W, H, 0);
 #elif defined(WIN32)
-  fl_pop_clip(); 
   data = fl_read_image(NULL, 0, 0, width, height, 0);
-  HDC gc = (HDC)driver()->gc();
-  RestoreDC(gc, _savedc);
-  DeleteDC(gc);
-  _ss->set_current(); 
-  fl_window=_sw; 
-  _ss->driver()->gc(_sgc);
+  end_current();
+  previous->driver()->gc(_sgc);
 #elif defined(FL_PORTING)
 #  pragma message "FL_PORTING: implement Fl_Image_Surface"
 #else
-  fl_pop_clip(); 
   data = fl_read_image(NULL, 0, 0, width, height, 0);
-  fl_window = pre_window; 
-  previous->set_current();
+  end_current();
 #endif
   Fl_RGB_Image *image = new Fl_RGB_Image(data, W, H);
   image->alloc_array = 1;
@@ -141,32 +151,49 @@ Fl_Shared_Image* Fl_Image_Surface::highres_image()
 
 void Fl_Image_Surface::set_current()
 {
+  pre_window = fl_window;
+  if (!previous) previous = Fl_Surface_Device::surface();
 #if defined(__APPLE__) // PORTME: Fl_Surface_Driver - platform image surface
   driver()->gc(offscreen);
   fl_window = 0;
   Fl_Surface_Device::set_current();
+  was_high = Fl_Display_Device::high_resolution();
   Fl_X::set_high_resolution( CGBitmapContextGetWidth(offscreen) > width );
 #elif defined(WIN32)
-  _sw = fl_window;
-  _ss = Fl_Surface_Device::surface(); 
-  _sgc = (HDC)_ss->driver()->gc();
+  if (!_sgc) _sgc = (HDC)previous->driver()->gc();
   HDC gc = fl_makeDC(offscreen);
   Fl_Surface_Device::set_current();
   driver()->gc(gc);
-   _savedc = SaveDC(gc);
-  fl_window=(HWND)offscreen; 
+  _savedc = SaveDC(gc);
+  fl_window=(HWND)offscreen;
   fl_push_no_clip();
 #elif defined(FL_PORTING)
 #  pragma message "FL_PORTING: implement Fl_Image_Surface"
 #else
-  pre_window = fl_window; 
-  fl_window = offscreen; 
-  previous = Fl_Surface_Device::surface(); 
+  fl_window = offscreen;
   Fl_Surface_Device::set_current();
   fl_push_no_clip();
 #endif
 }
 
+void Fl_Image_Surface::end_current()
+{
+#if defined(__APPLE__)
+  Fl_X::set_high_resolution(was_high);
+#elif defined(WIN32)
+  HDC gc = (HDC)driver()->gc();
+  RestoreDC(gc, _savedc);
+  DeleteDC(gc);
+  fl_pop_clip();
+#elif defined(FL_PORTING)
+#  pragma message "FL_PORTING: implement Fl_Image_Surface"
+#else
+  fl_pop_clip();
+#endif
+  previous->Fl_Surface_Device::set_current();
+  fl_window = pre_window;
+}
+
 #if defined(__APPLE__) // PORTME: Fl_Surface_Driver - platform image surface
 
 void Fl_Image_Surface::translate(int x, int y) {
@@ -205,6 +232,76 @@ void Fl_Image_Surface::untranslate() {
 
 #endif
 
+static Fl_Image_Surface *offscreen_api_surface[20];
+static int count = 0;
+static int current;
+
+static int find_slot() { // return an available slot to memorize an Fl_Image_Surface object
+    for (int num = 0; num < count; num++) {
+        if (!offscreen_api_surface[num]) return num;
+      }
+    if (count >= sizeof(offscreen_api_surface)/sizeof(Fl_Image_Surface*)) return -1;
+    return count++;
+  }
+
+/** \addtogroup fl_drawings
+   @{
+   */
+
+/**
+   Creation of an offscreen graphics buffer.
+   \param w,h     width and height in pixels of the buffer.
+   \return    the created graphics buffer.
+   */
+Fl_Offscreen fl_create_offscreen(int w, int h) {
+  int rank = find_slot();
+  if (rank < 0) return NULL;
+  offscreen_api_surface[rank] = new Fl_Image_Surface(w, h);
+  return offscreen_api_surface[rank]->offscreen;
+}
+
+#if USE_X11
+Fl_Offscreen fl_create_offscreen_with_alpha(int w, int h) {
+  int rank = find_slot();
+  if (rank < 0) return NULL;
+  Fl_Offscreen pixmap = XCreatePixmap(fl_display, RootWindow(fl_display, fl_screen), w, h, 32);
+  offscreen_api_surface[rank] = new Fl_Image_Surface(pixmap, w, h);
+  return pixmap;
+}
+#endif
+
+/**  Deletion of an offscreen graphics buffer.
+   \param ctx     the buffer to be deleted.
+   */
+void fl_delete_offscreen(Fl_Offscreen ctx) {
+  if (!ctx) return;
+  for (int i = 0; i < count; i++) {
+    if (offscreen_api_surface[i] && offscreen_api_surface[i]->offscreen == ctx) {
+      delete offscreen_api_surface[i];
+      offscreen_api_surface[i] = NULL;
+    }
+  }
+}
+
+/**  Send all subsequent drawing commands to this offscreen buffer.
+   \param ctx     the offscreen buffer.
+   */
+void fl_begin_offscreen(Fl_Offscreen ctx) {
+  for (current = 0; current < count; current++) {
+    if (offscreen_api_surface[current] && offscreen_api_surface[current]->offscreen == ctx) {
+      offscreen_api_surface[current]->set_current();
+      return;
+    }
+  }
+}
+
+/** Quit sending drawing commands to the current offscreen buffer.
+   */
+void fl_end_offscreen() {
+  offscreen_api_surface[current]->end_current();
+}
+
+/** @} */
 
 
 //
diff --git a/src/Fl_cocoa.mm b/src/Fl_cocoa.mm
index 898c68136..5b70130ad 100644
--- a/src/Fl_cocoa.mm
+++ b/src/Fl_cocoa.mm
@@ -3309,7 +3309,7 @@ void Fl_X::q_release_context(Fl_X *x) {
   if (!gc) return;
   CGContextRestoreGState(gc); // match the CGContextSaveGState's of make_current
   CGContextRestoreGState(gc);
-  Fl_X::set_high_resolution(false);
+//  Fl_X::set_high_resolution(false);
   CGContextFlush(gc);
   Fl_Display_Device::display_device()->driver()->gc(0);
 #if defined(FLTK_USE_CAIRO)
@@ -3886,12 +3886,13 @@ static NSImage *imageFromText(const char *text, int *pwidth, int *pheight)
   }
   height = nl * fl_height() + 3;
   width += 6;
-  Fl_Offscreen off = Fl_Quartz_Graphics_Driver::create_offscreen_with_alpha(width, height);
+  Fl_Offscreen off = fl_create_offscreen(width, height);
   fl_begin_offscreen(off);
   CGContextSetRGBFillColor( (CGContextRef)off, 0,0,0,0);
   fl_rectf(0,0,width,height);
   fl_color(FL_BLACK);
   p = text;
+  fl_font(FL_HELVETICA, 10);
   int y = fl_height();
   while(TRUE) {
     q = strchr(p, '\n');
@@ -3922,7 +3923,7 @@ static NSImage *defaultDragImage(int *pwidth, int *pheight)
   else {
     width = 16; height = 16;
     }
-  Fl_Offscreen off = Fl_Quartz_Graphics_Driver::create_offscreen_with_alpha(width, height);
+  Fl_Offscreen off = fl_create_offscreen(width, height);
   fl_begin_offscreen(off);
   if (fl_mac_os_version >= version_threshold) {
     fl_font(FL_HELVETICA, 20);
diff --git a/src/drivers/GDI/Fl_GDI_Graphics_Driver_image.cxx b/src/drivers/GDI/Fl_GDI_Graphics_Driver_image.cxx
index 4a1c6e007..f750e1785 100644
--- a/src/drivers/GDI/Fl_GDI_Graphics_Driver_image.cxx
+++ b/src/drivers/GDI/Fl_GDI_Graphics_Driver_image.cxx
@@ -173,7 +173,7 @@ static void innards(const uchar *buf, int X, int Y, int W, int H,
   int blocking = h;
   {int size = linesize*h;
   // when printing, don't limit buffer size not to get a crash in StretchDIBits
-  if (size > MAXBUFFER && Fl_Surface_Device::surface() == Fl_Display_Device::display_device()) {
+  if (size > MAXBUFFER && !fl_graphics_driver->has_feature(Fl_Graphics_Driver::PRINTER)) {
     size = MAXBUFFER;
     blocking = MAXBUFFER/linesize;
   }
@@ -251,7 +251,7 @@ static void innards(const uchar *buf, int X, int Y, int W, int H,
         }            
       }
     }
-    if (Fl_Surface_Device::surface() != Fl_Display_Device::display_device()) {
+    if (fl_graphics_driver->has_feature(Fl_Graphics_Driver::PRINTER)) {
       // if print context, device and logical units are not equal, so SetDIBitsToDevice
       // does not do the expected job, whereas StretchDIBits does it.
       StretchDIBits(gc, x, y+j-k, w, k, 0, 0, w, k,
@@ -633,11 +633,11 @@ fl_uintptr_t Fl_GDI_Graphics_Driver::cache(Fl_Pixmap *img, int w, int h, const c
   id = fl_create_offscreen(w, h);
   fl_begin_offscreen(id);
   uchar *bitmap = 0;
-  mask_bitmap(&bitmap);
+  fl_graphics_driver->mask_bitmap(&bitmap);
   fl_draw_pixmap(data, 0, 0, FL_BLACK);
   extern UINT win_pixmap_bg_color; // computed by fl_draw_pixmap()
   img->pixmap_bg_color = win_pixmap_bg_color;
-  mask_bitmap(0);
+  fl_graphics_driver->mask_bitmap(0);
   if (bitmap) {
     img->mask_ = (fl_uintptr_t)fl_create_bitmask(w, h, bitmap);
     delete[] bitmap;
diff --git a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx
index 7186a030a..f1b159960 100644
--- a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx
+++ b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx
@@ -40,16 +40,6 @@ Fl_Graphics_Driver *Fl_Graphics_Driver::newMainGraphicsDriver()
   return new Fl_Quartz_Graphics_Driver();
 }
 
-#ifndef FL_DOXYGEN
-Fl_Offscreen Fl_Quartz_Graphics_Driver::create_offscreen_with_alpha(int w, int h) {
-  void *data = calloc(w*h,4);
-  CGColorSpaceRef lut = CGColorSpaceCreateDeviceRGB();
-  CGContextRef ctx = CGBitmapContextCreate(data, w, h, 8, w*4, lut, kCGImageAlphaPremultipliedLast);
-  CGColorSpaceRelease(lut);
-  return (Fl_Offscreen)ctx;
-}
-#endif
-
 char Fl_Quartz_Graphics_Driver::can_do_alpha_blending() {
   return 1;
 }
@@ -80,86 +70,6 @@ void Fl_Quartz_Graphics_Driver::copy_offscreen(int x,int y,int w,int h,Fl_Offscr
   CGDataProviderRelease(src_bytes);
 }
 
-/** \addtogroup fl_drawings
- @{
- */
-
-// FIXME: driver system
-/**
- Creation of an offscreen graphics buffer.
- \param w,h     width and height in pixels of the buffer.
- \return    the created graphics buffer.
- */
-Fl_Offscreen fl_create_offscreen(int w, int h) {
-  void *data = calloc(w*h,4);
-  CGColorSpaceRef lut = CGColorSpaceCreateDeviceRGB();
-  CGContextRef ctx = CGBitmapContextCreate(
-                                           data, w, h, 8, w*4, lut, kCGImageAlphaNoneSkipLast);
-  CGColorSpaceRelease(lut);
-  return (Fl_Offscreen)ctx;
-}
-
-// FIXME: driver system
-/**  Deletion of an offscreen graphics buffer.
- \param ctx     the buffer to be deleted.
- */
-void fl_delete_offscreen(Fl_Offscreen ctx) {
-  if (!ctx) return;
-  void *data = CGBitmapContextGetData((CGContextRef)ctx);
-  CFIndex count = CFGetRetainCount(ctx);
-  CGContextRelease((CGContextRef)ctx);
-  if(count == 1) free(data);
-}
-
-// FIXME: driver system
-const int stack_max = 16;
-static int stack_ix = 0;
-static CGContextRef stack_gc[stack_max];
-static Window stack_window[stack_max];
-static Fl_Surface_Device *_ss;
-
-// FIXME: driver system
-/**  Send all subsequent drawing commands to this offscreen buffer.
- \param ctx     the offscreen buffer.
- */
-void fl_begin_offscreen(Fl_Offscreen ctx) {
-  _ss = Fl_Surface_Device::surface();
-  Fl_Display_Device::display_device()->set_current();
-  if (stack_ix<stack_max) {
-    stack_gc[stack_ix] = (CGContextRef)fl_graphics_driver->gc();
-    stack_window[stack_ix] = fl_window;
-  } else
-    fprintf(stderr, "FLTK CGContext Stack overflow error\n");
-  stack_ix++;
-
-  fl_graphics_driver->gc(ctx);
-  fl_window = 0;
-  CGContextSaveGState(ctx);
-  fl_graphics_driver->push_no_clip();
-}
-
-// FIXME: driver system
-/** Quit sending drawing commands to the current offscreen buffer.
- */
-void fl_end_offscreen() {
-  fl_graphics_driver->pop_clip();
-  CGContextRef gc = (CGContextRef)fl_graphics_driver->gc();
-
-  CGContextRestoreGState(gc); // matches CGContextSaveGState in fl_begin_offscreen()
-  CGContextFlush(gc);
-  if (stack_ix>0)
-    stack_ix--;
-  else
-    fprintf(stderr, "FLTK CGContext Stack underflow error\n");
-  if (stack_ix<stack_max) {
-    fl_graphics_driver->gc(stack_gc[stack_ix]);
-    fl_window = stack_window[stack_ix];
-  }
-  _ss->set_current();
-}
-
-/** @} */
-
 //
 // End of "$Id$".
 //
diff --git a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver_image.cxx b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver_image.cxx
index a72e09b1e..3574adce5 100644
--- a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver_image.cxx
+++ b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver_image.cxx
@@ -301,8 +301,7 @@ fl_uintptr_t Fl_Quartz_Graphics_Driver::cache(Fl_Bitmap*, int w, int h, const uc
 }
 
 fl_uintptr_t Fl_Quartz_Graphics_Driver::cache(Fl_Pixmap *img, int w, int h, const char *const*data) {
-  Fl_Offscreen id;
-  id = create_offscreen_with_alpha(w, h);
+  Fl_Offscreen id = fl_create_offscreen(w, h);
   fl_begin_offscreen(id);
   fl_draw_pixmap(data, 0, 0, FL_BLACK);
   fl_end_offscreen();
diff --git a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx
index e1da7df3f..723c22838 100644
--- a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx
+++ b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx
@@ -812,9 +812,9 @@ fl_uintptr_t Fl_Xlib_Graphics_Driver::cache(Fl_Pixmap *img, int w, int h, const
   id = fl_create_offscreen(w, h);
   fl_begin_offscreen(id);
   uchar *bitmap = 0;
-  mask_bitmap(&bitmap);
+  fl_graphics_driver->mask_bitmap(&bitmap);
   fl_draw_pixmap(data, 0, 0, FL_BLACK);
-  mask_bitmap(0);
+  fl_graphics_driver->mask_bitmap(0);
   if (bitmap) {
     img->mask_ = (fl_uintptr_t)fl_create_bitmask(w, h, bitmap);
     delete[] bitmap;