Add support of Fl_Region to the Cairo graphics driver

and remove it from the Wayland graphics driver.

FL/platform_types.h

@@ -115,7 +115,7 @@ typedef struct HGLRC__ *GLContext;
 
 #elif defined(FLTK_USE_WAYLAND)
 typedef struct fl_wld_buffer *Fl_Offscreen; /**< an offscreen drawing buffer */
-typedef struct flWaylandRegion* Fl_Region;
+typedef struct flCairoRegion* Fl_Region;
 typedef int FL_SOCKET; /**< socket or file descriptor */
 typedef void *EGLContext;
 typedef EGLContext GLContext;

FL/wayland.H

@@ -20,7 +20,7 @@
 
 typedef struct wld_window *Window;
 
-struct flWaylandRegion {
+struct flCairoRegion {
   int count;
   struct _cairo_rectangle *rects;
 }; // a region is the union of a series of rectangles

FL/x11.H

@@ -86,6 +86,13 @@ extern FL_EXPORT Fl_XFont_On_Demand fl_xfont;
 
 extern FL_EXPORT char fl_override_redirect; // hack into Fl_X::make_xid()
 
+#if USE_PANGO
+struct flCairoRegion {
+  int count;
+  struct _cairo_rectangle *rects;
+}; // a region is the union of a series of rectangles
+#endif
+
 #endif // FL_LIBRARY || FL_INTERNALS
 
 #endif // FL_DOXYGEN

src/drivers/Cairo/Fl_Cairo_Graphics_Driver.H

@@ -176,6 +176,9 @@ public:
   virtual const char *font_name(int num);
   virtual void font_name(int num, const char *name);  virtual const char* get_font_name(Fl_Font fnum, int* ap);
   virtual int get_font_sizes(Fl_Font fnum, int*& sizep);
+  virtual Fl_Region XRectangleRegion(int x, int y, int w, int h);
+  virtual void XDestroyRegion(Fl_Region r);
+  virtual void add_rectangle_to_region(Fl_Region r, int X, int Y, int W, int H);
 };
 
 #endif // FL_CAIRO_GRAPHICS_DRIVER_H

src/drivers/Cairo/Fl_Cairo_Graphics_Driver.cxx

@@ -621,11 +621,6 @@ int Fl_Cairo_Graphics_Driver::clip_box(int x, int y, int w, int h, int &X, int &
 }
 
 
-void Fl_Cairo_Graphics_Driver::restore_clip() {
-  if (cairo_) cairo_reset_clip(cairo_);
-}
-
-
 void Fl_Cairo_Graphics_Driver::point(int x, int y) {
   rectf(x, y, 1, 1);
 }
@@ -1178,5 +1173,63 @@ void Fl_Cairo_Graphics_Driver::text_extents(const char* txt, int n, int& dx, int
   h = ink_rect.height;
 }
 
+//
+// Region-handling member functions.
+// They are used ONLY if the cairo graphics driver is the display graphics driver.
+// They are not used if the cairo graphics driver is used to draw PostScript.
+//
+
+Fl_Region Fl_Cairo_Graphics_Driver::XRectangleRegion(int x, int y, int w, int h) {
+  struct flCairoRegion *R = (struct flCairoRegion*)malloc(sizeof(*R));
+  R->count = 1;
+  R->rects = (cairo_rectangle_t *)malloc(sizeof(cairo_rectangle_t));
+  R->rects->x=x, R->rects->y=y, R->rects->width=w; R->rects->height=h;
+  return (Fl_Region)R;
+}
+
+
+// r1 ⊂ r2
+static bool CairoRectContainsRect(cairo_rectangle_t *r1, cairo_rectangle_t *r2) {
+  return r1->x >= r2->x && r1->y >= r2->y && r1->x+r1->width <= r2->x+r2->width &&
+    r1->y+r1->height <= r2->y+r2->height;
+}
+
+
+void Fl_Cairo_Graphics_Driver::add_rectangle_to_region(Fl_Region r_, int X, int Y, int W, int H) {
+  struct flCairoRegion *r = (struct flCairoRegion*)r_;
+  cairo_rectangle_t arg = {double(X), double(Y), double(W), double(H)};
+  int j; // don't add a rectangle totally inside the Fl_Region
+  for (j = 0; j < r->count; j++) {
+    if (CairoRectContainsRect(&arg, &(r->rects[j]))) break;
+  }
+  if (j >= r->count) {
+    r->rects = (cairo_rectangle_t*)realloc(r->rects, (++(r->count)) * sizeof(cairo_rectangle_t));
+    r->rects[r->count - 1] = arg;
+  }
+}
+
+
+void Fl_Cairo_Graphics_Driver::XDestroyRegion(Fl_Region r_) {
+  if (r_) {
+    struct flCairoRegion *r = (struct flCairoRegion*)r_;
+    free(r->rects);
+    free(r);
+  }
+}
+
+
+void Fl_Cairo_Graphics_Driver::restore_clip() {
+  if (cairo_) {
+    cairo_reset_clip(cairo_);
+    // apply what's in rstack
+    struct flCairoRegion *r = (struct flCairoRegion*)rstack[rstackptr];
+    if (r) {
+      for (int i = 0; i < r->count; i++) {
+        cairo_rectangle(cairo_, r->rects[i].x, r->rects[i].y, r->rects[i].width, r->rects[i].height);
+      }
+      cairo_clip(cairo_);
+    }
+  }
+}
 
 #endif // USE_PANGO

src/drivers/Wayland/Fl_Wayland_Graphics_Driver.H

@@ -77,10 +77,6 @@ public:
   Fl_Wayland_Graphics_Driver();
   static const uint32_t wld_format;
   void activate(struct fl_wld_buffer *buffer, float scale);
-  void clip_region(Fl_Region r);
-  Fl_Region XRectangleRegion(int x, int y, int w, int h);
-  void add_rectangle_to_region(Fl_Region r, int X, int Y, int W, int H);
-  void XDestroyRegion(Fl_Region r);
   void set_color(Fl_Color i, unsigned c);
   void copy_offscreen(int x, int y, int w, int h, Fl_Offscreen osrc, int srcx, int srcy);
   static struct fl_wld_buffer *create_shm_buffer(int width, int height);

src/drivers/Wayland/Fl_Wayland_Graphics_Driver.cxx

@@ -177,56 +177,6 @@ void Fl_Wayland_Graphics_Driver::activate(struct fl_wld_buffer *buffer, float sc
 }
 
 
-void Fl_Wayland_Graphics_Driver::clip_region(Fl_Region r) {
-  if (cairo_) {
-    cairo_reset_clip(cairo_);
-    if (r) {
-      for (int i = 0; i < r->count; i++) {
-        cairo_rectangle(cairo_, r->rects[i].x-0.5 , r->rects[i].y-0.5 , r->rects[i].width  , r->rects[i].height);
-      }
-      cairo_clip(cairo_);
-    }
-  }
-}
-
-
-Fl_Region Fl_Wayland_Graphics_Driver::XRectangleRegion(int x, int y, int w, int h) {
-  Fl_Region R = (Fl_Region)malloc(sizeof(*R));
-  R->count = 1;
-  R->rects = (cairo_rectangle_t *)malloc(sizeof(cairo_rectangle_t));
-  R->rects->x=x, R->rects->y=y, R->rects->width=w; R->rects->height=h;
-  return R;
-}
-
-
-// r1 ⊂ r2
-static bool CairoRectContainsRect(cairo_rectangle_t *r1, cairo_rectangle_t *r2) {
-  return r1->x >= r2->x && r1->y >= r2->y && r1->x+r1->width <= r2->x+r2->width &&
-    r1->y+r1->height <= r2->y+r2->height;
-}
-
-
-void Fl_Wayland_Graphics_Driver::add_rectangle_to_region(Fl_Region r, int X, int Y, int W, int H) {
-  cairo_rectangle_t arg = {double(X), double(Y), double(W), double(H)};
-  int j; // don't add a rectangle totally inside the Fl_Region
-  for (j = 0; j < r->count; j++) {
-    if (CairoRectContainsRect(&arg, &(r->rects[j]))) break;
-  }
-  if (j >= r->count) {
-    r->rects = (cairo_rectangle_t*)realloc(r->rects, (++(r->count)) * sizeof(cairo_rectangle_t));
-    r->rects[r->count - 1] = arg;
-  }
-}
-
-
-void Fl_Wayland_Graphics_Driver::XDestroyRegion(Fl_Region r) {
-  if (r) {
-    free(r->rects);
-    free(r);
-  }
-}
-
-
 void Fl_Wayland_Graphics_Driver::set_color(Fl_Color i, unsigned c) {
   if (fl_cmap[i] != c) {
     fl_cmap[i] = c;