Fix for STR#3142 where fl_read_image() correctly reads GL data under X11, but ignores them under MSWindows and Mac OS X.

Moreover, fl_read_image() behaves differently with and without OS virtualization for X11 and MSWindows.
The patched function reads whatever is in the rectangle transmitted in arguments, with and without GL data, with and without subwindows,
on ‘true’ OS or on virtualized OS.


git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10436 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 47 insertions, 50 deletions

diff --git a/src/Fl_Gl_Device_Plugin.cxx b/src/Fl_Gl_Device_Plugin.cxx
index fbcb2f613..ed2889dbe 100644
--- a/src/Fl_Gl_Device_Plugin.cxx
+++ b/src/Fl_Gl_Device_Plugin.cxx
@@ -3,7 +3,7 @@
 //
 // implementation of class Fl_Gl_Device_Plugin for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2010 by Bill Spitzak and others.
+// Copyright 2010-2014 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -20,19 +20,36 @@
 #include <FL/Fl_Printer.H>
 #include <FL/Fl_Gl_Window.H>
 #include "Fl_Gl_Choice.H"
+#include <FL/Fl_RGB_Image.H>
 #include "FL/Fl.H"
-#ifndef __APPLE__
-#include "FL/fl_draw.H"
-#endif
 
 #if defined(__APPLE__)
-static void imgProviderReleaseData (void *info, const void *data, size_t size)
+uchar *convert_BGRA_to_RGB(uchar *baseAddress, int w, int h, int mByteWidth)
 {
-  free((void *)data);
+  uchar *newimg = new uchar[3*w*h];
+  uchar *to = newimg;
+  for (int i = 0; i < h; i++) {
+    uchar *from = baseAddress + i * mByteWidth;
+    for (int j = 0; j < w; j++, from += 4) {
+#if __ppc__
+      memcpy(to, from + 1, 3);
+      to += 3;
+#else
+      *(to++) = *(from+2);
+      *(to++) = *(from+1);
+      *(to++) = *from;
+#endif
+    }
+  }
+  delete[] baseAddress;
+  return newimg;
 }
 #endif
 
-static void print_gl_window(Fl_Gl_Window *glw, int x, int y, int height)
+static Fl_RGB_Image* capture_gl_rectangle(Fl_Gl_Window *glw, int x, int y, int w, int h)
+/* captures a rectangle of a Fl_Gl_Window window, and returns it as a RGB image
+ stored from bottom to top.
+ */
 {
 #if defined(__APPLE__)
   const int bytesperpixel = 4;
@@ -48,66 +65,46 @@ static void print_gl_window(Fl_Gl_Window *glw, int x, int y, int height)
   glPixelStorei(GL_PACK_SKIP_ROWS, 0);
   glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
   // Read a block of pixels from the frame buffer
-  int mByteWidth = glw->w() * bytesperpixel;                
+  int mByteWidth = w * bytesperpixel;
   mByteWidth = (mByteWidth + 3) & ~3;    // Align to 4 bytes
-  uchar *baseAddress = (uchar*)malloc(mByteWidth * glw->h());
-  glReadPixels(0, 0, glw->w(), glw->h(), 
+  uchar *baseAddress = new uchar[mByteWidth * h];
+  glReadPixels(x, glw->h() - (y+h), w, h,
 #if defined(__APPLE__)
-	       GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV,
+               GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV,
 #else
-	       GL_RGB, GL_UNSIGNED_BYTE,
+               GL_RGB, GL_UNSIGNED_BYTE,
 #endif
-	       baseAddress);
+               baseAddress);
   glPopClientAttrib();
 #if defined(__APPLE__)
-// kCGBitmapByteOrder32Host and CGBitmapInfo are supposed to arrive with 10.4
-// but some 10.4 don't have kCGBitmapByteOrder32Host, so we play a little #define game
-#if MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_4
-#define kCGBitmapByteOrder32Host 0
-#define CGBitmapInfo CGImageAlphaInfo
-#elif ! defined(kCGBitmapByteOrder32Host)
-#ifdef __BIG_ENDIAN__
-#define kCGBitmapByteOrder32Host (4 << 12)
-#else    /* Little endian. */
-#define kCGBitmapByteOrder32Host (2 << 12)
-#endif
+  baseAddress = convert_BGRA_to_RGB(baseAddress, w, h, mByteWidth);
+  mByteWidth = 3 * w;
 #endif
-  CGColorSpaceRef cSpace = CGColorSpaceCreateDeviceRGB();
-  CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, baseAddress, mByteWidth * glw->h(), imgProviderReleaseData);
-  CGImageRef image = CGImageCreate(glw->w(), glw->h(), 8, 8*bytesperpixel, mByteWidth, cSpace, 
-				   (CGBitmapInfo)(kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Host), 
-				   provider, NULL, false, kCGRenderingIntentDefault);
-  if(image == NULL) return;
-  CGContextSaveGState(fl_gc);
-  CGContextTranslateCTM(fl_gc, 0, height);
-  CGContextScaleCTM(fl_gc, 1.0f, -1.0f);
-  CGRect rect = { { x, height - y - glw->h() }, { glw->w(), glw->h() } };
-  Fl_X::q_begin_image(rect, 0, 0, glw->w(), glw->h());
-  CGContextDrawImage(fl_gc, rect, image);
-  Fl_X::q_end_image();
-  CGContextRestoreGState(fl_gc);
-  CGImageRelease(image);
-  CGColorSpaceRelease(cSpace);
-  CGDataProviderRelease(provider);  
-#else
-  fl_draw_image(baseAddress + (glw->h() - 1) * mByteWidth, x, y , glw->w(), glw->h(), bytesperpixel, - mByteWidth);
-  free(baseAddress);
-#endif // __APPLE__
+  Fl_RGB_Image *img = new Fl_RGB_Image(baseAddress, w, h, 3, mByteWidth);
+  img->alloc_array = 1;
+  return img;
 }
 
 /**
- This class will make sure that OpenGL printing is available if fltk_gl
- was linked to the program.
+ This class will make sure that OpenGL printing/screen capture is available if fltk_gl
+ was linked to the program
  */
 class Fl_Gl_Device_Plugin : public Fl_Device_Plugin {
 public:
   Fl_Gl_Device_Plugin() : Fl_Device_Plugin(name()) { }
   virtual const char *name() { return "opengl.device.fltk.org"; }
-  virtual int print(Fl_Widget *w, int x, int y, int height) {
+  virtual int print(Fl_Widget *w, int x, int y, int height /*useless*/) {
     Fl_Gl_Window *glw = w->as_gl_window();
     if (!glw) return 0;
-    print_gl_window(glw, x, y, height);
-    return 1; 
+    Fl_RGB_Image *img = capture_gl_rectangle(glw, 0, 0, glw->w(), glw->h());
+    fl_draw_image(img->array + (glw->h() - 1) * img->ld(), x, y , glw->w(), glw->h(), 3, - img->ld());
+    delete img;
+    return 1;
+  }
+  virtual Fl_RGB_Image* rectangle_capture(Fl_Widget *widget, int x, int y, int w, int h) {
+    Fl_Gl_Window *glw = widget->as_gl_window();
+    if (!glw) return NULL;
+    return capture_gl_rectangle(glw, x, y, w, h);
   }
 };