New member function Fl_Image_Surface::mask(Fl_RGB_Image*)

3 files changed, 93 insertions, 0 deletions

diff --git a/src/drivers/GDI/Fl_GDI_Graphics_Driver.H b/src/drivers/GDI/Fl_GDI_Graphics_Driver.H
index 4d1f45c82..03371c8c4 100644
--- a/src/drivers/GDI/Fl_GDI_Graphics_Driver.H
+++ b/src/drivers/GDI/Fl_GDI_Graphics_Driver.H
@@ -70,6 +70,7 @@ public:
 
   // --- bitmap stuff
   static HBITMAP create_bitmask(int w, int h, const uchar *array); // NOT virtual
+  static HBITMAP calc_HBITMAP_mask(Fl_RGB_Image *mask);
   void delete_bitmask(fl_uintptr_t bm) FL_OVERRIDE;
   HBITMAP create_alphamask(int w, int h, int d, int ld, const uchar *array);
   void draw_unscaled(const char* str, int n, int x, int y) FL_OVERRIDE;
diff --git a/src/drivers/GDI/Fl_GDI_Image_Surface_Driver.H b/src/drivers/GDI/Fl_GDI_Image_Surface_Driver.H
index d44d57cd6..129a4ecbc 100644
--- a/src/drivers/GDI/Fl_GDI_Image_Surface_Driver.H
+++ b/src/drivers/GDI/Fl_GDI_Image_Surface_Driver.H
@@ -26,6 +26,12 @@ class Fl_GDI_Image_Surface_Driver : public Fl_Image_Surface_Driver {
 public:
   HWND pre_window;
   int _savedc;
+  void mask(const Fl_RGB_Image *) FL_OVERRIDE;
+  struct shape_data_type {
+    HBITMAP background;
+    uchar *vBits;
+    Fl_RGB_Image* mask;
+  } *shape_data_;
   Fl_GDI_Image_Surface_Driver(int w, int h, int high_res, Fl_Offscreen off);
   ~Fl_GDI_Image_Surface_Driver();
   void set_current() FL_OVERRIDE;
diff --git a/src/drivers/GDI/Fl_GDI_Image_Surface_Driver.cxx b/src/drivers/GDI/Fl_GDI_Image_Surface_Driver.cxx
index 5a4d5ada7..7e1c2f24e 100644
--- a/src/drivers/GDI/Fl_GDI_Image_Surface_Driver.cxx
+++ b/src/drivers/GDI/Fl_GDI_Image_Surface_Driver.cxx
@@ -19,6 +19,7 @@
 #include "../WinAPI/Fl_WinAPI_Screen_Driver.H"
 #include "Fl_GDI_Image_Surface_Driver.H"
 #include <FL/platform.H>
+#include <FL/Fl_Bitmap.H>
 #include <windows.h>
 
 
@@ -35,10 +36,16 @@ Fl_GDI_Image_Surface_Driver::Fl_GDI_Image_Surface_Driver(int w, int h, int high_
   driver(Fl_Graphics_Driver::newMainGraphicsDriver());
   if (d != 1 && high_res) ((Fl_GDI_Graphics_Driver*)driver())->scale(d);
   origin.x = origin.y = 0;
+  shape_data_ = NULL;
 }
 
 
 Fl_GDI_Image_Surface_Driver::~Fl_GDI_Image_Surface_Driver() {
+  if (shape_data_ && shape_data_->background) {
+    DeleteObject(shape_data_->background);
+    delete shape_data_->mask;
+    free(shape_data_);
+  }
   if (offscreen && !external_offscreen) DeleteObject((HBITMAP)offscreen);
   delete driver();
 }
@@ -67,6 +74,43 @@ void Fl_GDI_Image_Surface_Driver::untranslate() {
 
 Fl_RGB_Image* Fl_GDI_Image_Surface_Driver::image()
 {
+  if (shape_data_ && shape_data_->background) {
+    // get the offscreen size in pixels
+    HDC gc = fl_makeDC((HBITMAP)offscreen);
+    BITMAPINFO bmi;
+    bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
+    bmi.bmiHeader.biCompression = BI_RGB;
+    bmi.bmiHeader.biPlanes = 1;
+    bmi.bmiHeader.biBitCount = 0;
+    bmi.bmiHeader.biSizeImage = 0;
+    GetDIBits(gc, (HBITMAP)offscreen, 0, 0, NULL, &bmi, DIB_RGB_COLORS);
+    int W = bmi.bmiHeader.biWidth;
+    int H = bmi.bmiHeader.biHeight;
+    int line_size = ((3*W+3)/4) * 4;
+
+    // read bits of main offscreen
+    uchar *dib_src = new uchar[line_size * H];
+    bmi.bmiHeader.biWidth = W;
+    bmi.bmiHeader.biHeight = H;
+    bmi.bmiHeader.biCompression = BI_RGB;
+    bmi.bmiHeader.biBitCount = 24;
+    GetDIBits(gc, (HBITMAP)offscreen, 0, H,
+                       dib_src, &bmi, DIB_RGB_COLORS);
+        
+    // draw above the secondary offscreen the main offscreen masked by shape_data_->mask
+    GdiFlush();
+    Fl_Image_Surface_Driver::copy_with_mask(shape_data_->mask, shape_data_->vBits, dib_src, ((3*W+3)/4) * 4, true);
+    delete shape_data_->mask;
+    delete[] dib_src;
+
+    // write bits of main offscreen
+    SetDIBits(gc, (HBITMAP)offscreen, 0, H, shape_data_->vBits, &bmi, DIB_RGB_COLORS);
+    DeleteDC(gc);
+    DeleteObject(shape_data_->background);
+    shape_data_->background = NULL;
+    free(shape_data_);
+    shape_data_ = NULL;
+   }
   Fl_RGB_Image *image = Fl::screen_driver()->read_win_rectangle( 0, 0, width, height, 0);
   return image;
 }
@@ -81,3 +125,45 @@ void Fl_GDI_Image_Surface_Driver::end_current()
   fl_window = pre_window;
   Fl_Surface_Device::end_current();
 }
+
+
+void Fl_GDI_Image_Surface_Driver::mask(const Fl_RGB_Image *mask) {
+  shape_data_ =  (struct shape_data_type*)calloc(1, sizeof(struct shape_data_type));
+  // get the offscreen size in pixels
+  HDC gc = fl_makeDC((HBITMAP)offscreen);
+  BITMAPINFO bmi;
+  bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
+  bmi.bmiHeader.biCompression = BI_RGB;
+  bmi.bmiHeader.biPlanes = 1;
+  bmi.bmiHeader.biBitCount = 0;
+  bmi.bmiHeader.biSizeImage = 0;
+
+  GetDIBits(gc, (HBITMAP)offscreen, 0, 0, NULL, &bmi, DIB_RGB_COLORS);
+  int W = bmi.bmiHeader.biWidth;
+  int H = bmi.bmiHeader.biHeight;
+  
+  shape_data_->mask = Fl_Image_Surface_Driver::RGB3_to_RGB1(mask, W, H);
+  
+  // duplicate current offscreen content to new offscreen
+  int line_size = ((3*W+3)/4) * 4;
+  uchar *dib = new uchar[line_size * H];  // create temporary buffer to read DIB
+  bmi.bmiHeader.biWidth = W;
+  bmi.bmiHeader.biHeight = H;
+  bmi.bmiHeader.biCompression = BI_RGB;
+  bmi.bmiHeader.biBitCount = 24;
+  
+  GetDIBits(gc, (HBITMAP)offscreen, 0, H, dib, &bmi, DIB_RGB_COLORS);
+  
+  HDC background_gc = CreateCompatibleDC(gc);
+  shape_data_->background = 
+    CreateDIBSection(background_gc, &bmi, DIB_RGB_COLORS,
+                     (void**)&shape_data_->vBits, NULL, 0);
+  if (!shape_data_->background) {
+    Fl::error("CreateDIBSection error=%lu", GetLastError());
+  }
+  memcpy(shape_data_->vBits, dib, H * line_size);
+  delete[] dib;
+  DeleteDC(background_gc);
+  DeleteDC(gc);
+}
+