Add support of Fl_Region to the Cairo graphics driver

and remove it from the Wayland graphics driver.

2 files changed, 61 insertions, 5 deletions

diff --git a/src/drivers/Cairo/Fl_Cairo_Graphics_Driver.H b/src/drivers/Cairo/Fl_Cairo_Graphics_Driver.H
index b291f63b0..8345fbd47 100644
--- a/src/drivers/Cairo/Fl_Cairo_Graphics_Driver.H
+++ b/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
diff --git a/src/drivers/Cairo/Fl_Cairo_Graphics_Driver.cxx b/src/drivers/Cairo/Fl_Cairo_Graphics_Driver.cxx
index 036fe5418..a93b128e5 100644
--- a/src/drivers/Cairo/Fl_Cairo_Graphics_Driver.cxx
+++ b/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