OK, I believe I fixed the transparency issues on WIN32. Please everyone, test the code on all machines.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.1@5436 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

5 files changed, 59 insertions, 8 deletions

diff --git a/FL/Enumerations.H b/FL/Enumerations.H
index 257af0eb7..0ed610131 100644
--- a/FL/Enumerations.H
+++ b/FL/Enumerations.H
@@ -401,6 +401,10 @@ enum Fl_Mode { // visual types and Fl_Gl_Window::mode() (values match Glut)
   FL_FAKE_SINGLE = 512	// Fake single buffered windows using double-buffer
 };
 
+// image alpha blending
+
+#define FL_IMAGE_WITH_ALPHA 0x40000000
+
 // damage masks
 
 enum Fl_Damage {
diff --git a/FL/win32.H b/FL/win32.H
index fdab206af..ad1b69369 100644
--- a/FL/win32.H
+++ b/FL/win32.H
@@ -132,6 +132,7 @@ extern FL_EXPORT HDC fl_makeDC(HBITMAP);
   fl_pop_clip(); RestoreDC(fl_gc, _savedc); DeleteDC(fl_gc); fl_window=_sw; fl_gc = _sgc
 
 FL_EXPORT void fl_copy_offscreen(int x,int y,int w,int h,HBITMAP pixmap,int srcx,int srcy);
+FL_EXPORT void fl_copy_offscreen_with_alpha(int x,int y,int w,int h,HBITMAP pixmap,int srcx,int srcy);
 #define fl_delete_offscreen(bitmap) DeleteObject(bitmap);
 
 // Bitmap masks
diff --git a/src/Fl_Double_Window.cxx b/src/Fl_Double_Window.cxx
index 4f87f0bc3..e648fa4ab 100644
--- a/src/Fl_Double_Window.cxx
+++ b/src/Fl_Double_Window.cxx
@@ -87,7 +87,6 @@ static fl_alpha_blend_func fl_alpha_blend = NULL;
  * and finds the required function if so.
  */
 char fl_can_do_alpha_blending() {
-  return 0;
   static char been_here = 0;
   static char can_do = 0;
   if (been_here) return can_do;
@@ -111,8 +110,16 @@ HDC fl_makeDC(HBITMAP bitmap) {
 }
 
 void fl_copy_offscreen(int x,int y,int w,int h,HBITMAP bitmap,int srcx,int srcy) {
-  static FL_BLENDFUNCTION blendfunc = { 0, 0, 255, 1};
+  HDC new_gc = CreateCompatibleDC(fl_gc);
+  int save = SaveDC(new_gc);
+  SelectObject(new_gc, bitmap);
+  BitBlt(fl_gc, x, y, w, h, new_gc, srcx, srcy, SRCCOPY);
+  RestoreDC(new_gc, save);
+  DeleteDC(new_gc);
+}
 
+void fl_copy_offscreen_with_alpha(int x,int y,int w,int h,HBITMAP bitmap,int srcx,int srcy) {
+  static FL_BLENDFUNCTION blendfunc = { 0, 0, 255, 1};
   HDC new_gc = CreateCompatibleDC(fl_gc);
   int save = SaveDC(new_gc);
   SelectObject(new_gc, bitmap);
diff --git a/src/Fl_Image.cxx b/src/Fl_Image.cxx
index f1247512a..649b1373e 100644
--- a/src/Fl_Image.cxx
+++ b/src/Fl_Image.cxx
@@ -331,7 +331,7 @@ void Fl_RGB_Image::draw(int XP, int YP, int WP, int HP, int cx, int cy) {
   // account for current clip region (faster on Irix):
   int X,Y,W,H; fl_clip_box(XP,YP,WP,HP,X,Y,W,H);
   cx += X-XP; cy += Y-YP;
-  // clip the box down to the size of image, quit if empty:
+ // clip the box down to the size of image, quit if empty:
   if (cx < 0) {W += cx; X -= cx; cx = 0;}
   if (cx+W > w()) W = w()-cx;
   if (W <= 0) return;
@@ -347,12 +347,26 @@ void Fl_RGB_Image::draw(int XP, int YP, int WP, int HP, int cx, int cy) {
         src, 0L, false, kCGRenderingIntentDefault);
     CGColorSpaceRelease(lut);
     CGDataProviderRelease(src);
+#elif defined(WIN32)
+    id = fl_create_offscreen(w(), h());
+    if (d() == 2 || d() == 4 && fl_can_do_alpha_blending()) {
+      fl_begin_offscreen((Fl_Offscreen)id);
+      fl_draw_image(array, 0, 0, w(), h(), d()|FL_IMAGE_WITH_ALPHA, ld());
+      fl_end_offscreen();
+    } else {
+      fl_begin_offscreen((Fl_Offscreen)id);
+      fl_draw_image(array, 0, 0, w(), h(), d(), ld());
+      fl_end_offscreen();
+      if (d() == 2 || d() == 4) {
+        mask = fl_create_alphamask(w(), h(), d(), ld(), array);
+      }
+    }
 #else
     id = fl_create_offscreen(w(), h());
     fl_begin_offscreen((Fl_Offscreen)id);
     fl_draw_image(array, 0, 0, w(), h(), d(), ld());
     fl_end_offscreen();
-    if (d() == 2 || d() == 4 && !fl_can_do_alpha_blending()) {
+    if (d() == 2 || d() == 4) {
       mask = fl_create_alphamask(w(), h(), d(), ld(), array);
     }
 #endif
@@ -367,6 +381,8 @@ void Fl_RGB_Image::draw(int XP, int YP, int WP, int HP, int cx, int cy) {
     BitBlt(fl_gc, X, Y, W, H, new_gc, cx, cy, SRCPAINT);
     RestoreDC(new_gc,save);
     DeleteDC(new_gc);
+  } else if (d()==2 || d()==4) {
+    fl_copy_offscreen_with_alpha(X, Y, W, H, (Fl_Offscreen)id, cx, cy);
   } else {
     fl_copy_offscreen(X, Y, W, H, (Fl_Offscreen)id, cx, cy);
   }
diff --git a/src/fl_draw_image_win32.cxx b/src/fl_draw_image_win32.cxx
index f55ca9720..05fc7ee8c 100644
--- a/src/fl_draw_image_win32.cxx
+++ b/src/fl_draw_image_win32.cxx
@@ -259,18 +259,41 @@ static void innards(const uchar *buf, int X, int Y, int W, int H,
 static int fl_abs(int v) { return v<0 ? -v : v; }
 
 void fl_draw_image(const uchar* buf, int x, int y, int w, int h, int d, int l){
-  innards(buf,x,y,w,h,d,l,fl_abs(d),0,0);
+  if (fl_abs(d)&FL_IMAGE_WITH_ALPHA) {
+    d ^= FL_IMAGE_WITH_ALPHA;
+    innards(buf,x,y,w,h,d,l,fl_abs(d),0,0);
+  } else {
+    innards(buf,x,y,w,h,d,l,(d<3&&d>-3),0,0);
+  }
 }
+
 void fl_draw_image(Fl_Draw_Image_Cb cb, void* data,
 		   int x, int y, int w, int h,int d) {
-  innards(0,x,y,w,h,d,0,fl_abs(d),cb,data);
+  if (fl_abs(d)&FL_IMAGE_WITH_ALPHA) {
+    d ^= FL_IMAGE_WITH_ALPHA;
+    innards(0,x,y,w,h,d,0,(d<3&&d>-3),cb,data);
+  } else {
+    innards(0,x,y,w,h,d,0,(d<3&&d>-3),cb,data);
+  }
 }
+
 void fl_draw_image_mono(const uchar* buf, int x, int y, int w, int h, int d, int l){
-  innards(buf,x,y,w,h,d,l,fl_abs(d),0,0);
+  if (fl_abs(d)&FL_IMAGE_WITH_ALPHA) {
+    d ^= FL_IMAGE_WITH_ALPHA;
+    innards(buf,x,y,w,h,d,l,1,0,0);
+  } else {
+    innards(buf,x,y,w,h,d,l,1,0,0);
+  }
 }
+
 void fl_draw_image_mono(Fl_Draw_Image_Cb cb, void* data,
 		   int x, int y, int w, int h,int d) {
-  innards(0,x,y,w,h,d,0,fl_abs(d),cb,data);
+  if (fl_abs(d)&FL_IMAGE_WITH_ALPHA) {
+    d ^= FL_IMAGE_WITH_ALPHA;
+    innards(0,x,y,w,h,d,0,1,cb,data);
+  } else {
+    innards(0,x,y,w,h,d,0,1,cb,data);
+  }
 }
 
 void fl_rectf(int x, int y, int w, int h, uchar r, uchar g, uchar b) {