Use type cairo_region_t* for Fl_Region under Wayland platform

FL/platform_types.h

@@ -49,7 +49,7 @@ typedef opaque Fl_Offscreen;
  Pointer to a platform-specific structure representing a collection of rectangles.
   \note This pointer can be safely cast to these types on each platform:
   \li X11: Region as defined by X11
-  \li Wayland: struct flCairoRegion *
+  \li Wayland:  cairo_region_t *
   \li Windows: HRGN
   \li macOS:  struct flCocoaRegion *
  */

src/drivers/Cairo/Fl_Cairo_Graphics_Driver.H

@@ -28,10 +28,6 @@ typedef struct _PangoLayout  PangoLayout;
 typedef struct _PangoContext PangoContext;
 typedef struct _PangoFontDescription PangoFontDescription;
 
-struct flCairoRegion {
-  int count;
-  struct _cairo_rectangle *rects;
-}; // a region is the union of a series of rectangles
 
 class Fl_Cairo_Font_Descriptor : public Fl_Font_Descriptor {
 public:

src/drivers/Cairo/Fl_Cairo_Graphics_Driver.cxx

@@ -1396,41 +1396,19 @@ void Fl_Cairo_Graphics_Driver::text_extents(const char* txt, int n, int& dx, int
 //
 
 Fl_Region Fl_Cairo_Graphics_Driver::XRectangleRegion(int x, int y, int w, int h) {
-  struct flCairoRegion *R = (struct flCairoRegion*)malloc(sizeof(*R));
+  cairo_rectangle_int_t rect = {x, y, w, h};
-  R->count = 1;
+  return cairo_region_create_rectangle(&rect);
-  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_int_t rect = {X, Y, W, H};
-  cairo_rectangle_t arg = {double(X), double(Y), double(W), double(H)};
+  cairo_region_union_rectangle((cairo_region_t*)r_, &rect);
-  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_) {
+  cairo_region_destroy((cairo_region_t*)r_);
-    struct flCairoRegion *r = (struct flCairoRegion*)r_;
-    free(r->rects);
-    free(r);
-  }
 }
 
 #define fl_max(a,b) ((a) > (b) ? (a) : (b))
@@ -1440,27 +1418,24 @@ 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];
+    cairo_region_t *r = (cairo_region_t*)rstack[rstackptr];
     if (r) {
       if (!clip_) {
         clip_ = new Clip();
         clip_->prev = NULL;
       }
-      for (int i = 0; i < r->count; i++) {
+      int count = cairo_region_num_rectangles(r);
-        cairo_rectangle(cairo_, r->rects[i].x - 0.5, r->rects[i].y - 0.5, r->rects[i].width, r->rects[i].height);
+      cairo_rectangle_int_t rect;
-        // put in clip_ the bounding rect of region r
+      for (int i = 0; i < count; i++) {
-        if (i == 0) {
+        cairo_region_get_rectangle(r, i, &rect);
-          clip_->x = r->rects[0].x; clip_->y = r->rects[0].y;
+        cairo_rectangle(cairo_, rect.x - 0.5, rect.y - 0.5, rect.width, rect.height);
-          clip_->w = r->rects[0].width; clip_->h = r->rects[0].height;
-        } else {
-          int R = fl_max(r->rects[i].x + r->rects[i].width, clip_->x + clip_->w);
-          int B = fl_max(r->rects[i].y + r->rects[i].height, clip_->y + clip_->h);
-          clip_->x = fl_min(r->rects[i].x, clip_->x) ;
-          clip_->y = fl_min(r->rects[i].y, clip_->y);
-          clip_->w = R - clip_->x;
-          clip_->h = B - clip_->y;
-        }
       }
+      // put in clip_ the bounding rect of region r
+      cairo_region_get_extents(r, &rect);
+      clip_->x = rect.x;
+      clip_->y = rect.y;
+      clip_->w = rect.width;
+      clip_->h = rect.height;
       cairo_clip(cairo_);
     } else if (clip_) {
       clip_->w = -1;

src/drivers/Wayland/Fl_Wayland_Graphics_Driver.H

@@ -60,7 +60,7 @@ public:
   static struct wld_buffer *create_wld_buffer(int width, int height, bool with_shm = true);
   static void create_shm_buffer(wld_buffer *buffer);
   static void buffer_release(struct wld_window *window);
-  static void buffer_commit(struct wld_window *window, struct flCairoRegion *r = NULL);
+  static void buffer_commit(struct wld_window *window, cairo_region_t *r = NULL);
   static void cairo_init(struct draw_buffer *buffer, int width, int height, int stride,
                          cairo_format_t format);
   // used by class Fl_Wayland_Gl_Window_Driver

src/drivers/Wayland/Fl_Wayland_Graphics_Driver.cxx

@@ -22,7 +22,7 @@
 #include <unistd.h> // for close()
 #include <errno.h>
 #include <string.h> // for strerror()
-
+#include <cairo/cairo.h>
 
 extern "C" {
 #  include "../../../libdecor/src/os-compatibility.h" // for libdecor_os_create_anonymous_file()
@@ -139,15 +139,18 @@ const struct wl_callback_listener *Fl_Wayland_Graphics_Driver::p_surface_frame_l
 
 
 // copy pixels in region r from the Cairo surface to the Wayland buffer
-static void copy_region(struct wld_window *window, struct flCairoRegion *r) {
+static void copy_region(struct wld_window *window, cairo_region_t *r) {
   struct Fl_Wayland_Graphics_Driver::wld_buffer *buffer = window->buffer;
   float f = Fl::screen_scale(window->fl_win->screen_num()) *
     Fl_Wayland_Window_Driver::driver(window->fl_win)->wld_scale();
-  for (int i = 0; i < r->count; i++) {
+  int count = cairo_region_num_rectangles(r);
-    int left = r->rects[i].x * f;
+  cairo_rectangle_int_t rect;
-    int top = r->rects[i].y * f;
+  for (int i = 0; i < count; i++) {
-    int width = r->rects[i].width * f;
+    cairo_region_get_rectangle(r, i, &rect);
-    int height = r->rects[i].height * f;
+    int left = rect.x * f;
+    int top = rect.y * f;
+    int width = rect.width * f;
+    int height = rect.height * f;
     int offset = top * buffer->draw_buffer.stride + 4 * left;
     int W4 = 4 * width;
     for (int l = 0; l < height; l++) {
@@ -163,7 +166,7 @@ static void copy_region(struct wld_window *window, struct flCairoRegion *r) {
 }
 
 
-void Fl_Wayland_Graphics_Driver::buffer_commit(struct wld_window *window, struct flCairoRegion *r)
+void Fl_Wayland_Graphics_Driver::buffer_commit(struct wld_window *window, cairo_region_t *r)
 {
   if (!window->buffer->wl_buffer) create_shm_buffer(window->buffer);
   cairo_surface_t *surf = cairo_get_target(window->buffer->draw_buffer.cairo_);

src/drivers/Wayland/Fl_Wayland_Window_Driver.cxx

@@ -408,7 +408,7 @@ void Fl_Wayland_Window_Driver::flush() {
   if (!window || !window->configured_width) return;
 
   Fl_X *ip = Fl_X::flx(pWindow);
-  struct flCairoRegion* r = (struct flCairoRegion*)ip->region;
+  cairo_region_t* r = (cairo_region_t*)ip->region;
   if (!window->buffer || pWindow->as_overlay_window()) r = NULL;
 
   Fl_Wayland_Window_Driver::in_flush_ = true;