New member function Fl_Image_Surface::mask(Fl_RGB_Image*)

2 files changed, 80 insertions, 1 deletions

diff --git a/src/drivers/Wayland/Fl_Wayland_Image_Surface_Driver.H b/src/drivers/Wayland/Fl_Wayland_Image_Surface_Driver.H
index 285222ced..ae32ac3df 100644
--- a/src/drivers/Wayland/Fl_Wayland_Image_Surface_Driver.H
+++ b/src/drivers/Wayland/Fl_Wayland_Image_Surface_Driver.H
@@ -25,6 +25,12 @@ class Fl_Wayland_Image_Surface_Driver : public Fl_Image_Surface_Driver {
 public:
   Fl_Wayland_Image_Surface_Driver(int w, int h, int high_res, Fl_Offscreen off);
   ~Fl_Wayland_Image_Surface_Driver();
+  void mask(const Fl_RGB_Image *) FL_OVERRIDE;
+  struct shape_data_type {
+    double scale;
+    cairo_pattern_t *mask_pattern_;
+    cairo_t *bg_cr;
+  } *shape_data_;
   void set_current() FL_OVERRIDE;
   void translate(int x, int y) FL_OVERRIDE;
   void untranslate() FL_OVERRIDE;
diff --git a/src/drivers/Wayland/Fl_Wayland_Image_Surface_Driver.cxx b/src/drivers/Wayland/Fl_Wayland_Image_Surface_Driver.cxx
index 83419e5b2..f25fe025d 100644
--- a/src/drivers/Wayland/Fl_Wayland_Image_Surface_Driver.cxx
+++ b/src/drivers/Wayland/Fl_Wayland_Image_Surface_Driver.cxx
@@ -22,6 +22,7 @@
 
 Fl_Wayland_Image_Surface_Driver::Fl_Wayland_Image_Surface_Driver(int w, int h,
       int high_res, Fl_Offscreen off) : Fl_Image_Surface_Driver(w, h, high_res, off) {
+  shape_data_ = NULL;
   float s = 1;
   int d = 1;
   if (!off) {
@@ -51,6 +52,19 @@ Fl_Wayland_Image_Surface_Driver::Fl_Wayland_Image_Surface_Driver(int w, int h,
 
 
 Fl_Wayland_Image_Surface_Driver::~Fl_Wayland_Image_Surface_Driver() {
+  if (shape_data_) {
+    cairo_surface_t *surf;
+    cairo_pattern_get_surface(shape_data_->mask_pattern_, &surf);
+    unsigned char *bits = cairo_image_surface_get_data(surf);
+    cairo_pattern_destroy(shape_data_->mask_pattern_);
+    delete[] bits;
+    struct Fl_Wayland_Graphics_Driver::draw_buffer *off_ =
+    Fl_Wayland_Graphics_Driver::offscreen_buffer((Fl_Offscreen)shape_data_->bg_cr);
+    delete[] off_->buffer;
+    free(off_);
+    cairo_destroy(shape_data_->bg_cr);
+    free(shape_data_);
+  }
   if (offscreen && !external_offscreen) {
     struct Fl_Wayland_Graphics_Driver::draw_buffer *buffer =
       Fl_Wayland_Graphics_Driver::offscreen_buffer(offscreen);
@@ -91,10 +105,38 @@ void Fl_Wayland_Image_Surface_Driver::untranslate() {
 
 
 Fl_RGB_Image* Fl_Wayland_Image_Surface_Driver::image() {
+  if (shape_data_ && shape_data_->mask_pattern_) {
+    // draw above the secondary offscreen the main offscreen masked by mask_pattern_
+    cairo_t *c = ((Fl_Cairo_Graphics_Driver*)driver())->cr();
+    cairo_pattern_t *paint_pattern = cairo_pattern_create_for_surface(cairo_get_target(c));
+    cairo_set_source(shape_data_->bg_cr, paint_pattern);
+    cairo_mask(shape_data_->bg_cr, shape_data_->mask_pattern_);
+    cairo_pattern_destroy(paint_pattern);
+    // copy secondary offscreen to the main offscreen
+    cairo_pattern_t *pat = cairo_pattern_create_for_surface(cairo_get_target(shape_data_->bg_cr));
+    cairo_scale(c, shape_data_->scale, shape_data_->scale);
+    cairo_set_source(c, pat),
+    cairo_paint(c);
+    cairo_pattern_destroy(pat);
+    // delete secondary offscreen
+    cairo_surface_t *surf;
+    cairo_pattern_get_surface(shape_data_->mask_pattern_, &surf);
+    unsigned char *bits = cairo_image_surface_get_data(surf);
+    cairo_pattern_destroy(shape_data_->mask_pattern_);
+    delete[] bits;
+    struct Fl_Wayland_Graphics_Driver::draw_buffer *off_ =
+    Fl_Wayland_Graphics_Driver::offscreen_buffer((Fl_Offscreen)shape_data_->bg_cr);
+    delete[] off_->buffer;
+    free(off_);
+    cairo_destroy(shape_data_->bg_cr);
+    free(shape_data_);
+    shape_data_ = NULL;
+  }
+  
   // Convert depth-4 image in draw_buffer to a depth-3 image while exchanging R and B colors
   struct Fl_Wayland_Graphics_Driver::draw_buffer *off_buf =
     Fl_Wayland_Graphics_Driver::offscreen_buffer(offscreen);
-  int height = off_buf->data_size / off_buf->stride;
+  int height = int(off_buf->data_size / off_buf->stride);
   uchar *rgb = new uchar[off_buf->width * height * 3];
   uchar *p = rgb;
   uchar *q;
@@ -111,3 +153,34 @@ Fl_RGB_Image* Fl_Wayland_Image_Surface_Driver::image() {
   image->alloc_array = 1;
   return image;
 }
+
+
+void Fl_Wayland_Image_Surface_Driver::mask(const Fl_RGB_Image *mask) {
+  bool using_copy = false;
+  shape_data_ =  (struct shape_data_type*)calloc(1, sizeof(struct shape_data_type));
+  int W, H;
+  struct Fl_Wayland_Graphics_Driver::draw_buffer *off_buf =
+  Fl_Wayland_Graphics_Driver::offscreen_buffer(offscreen);
+  W = off_buf->width;
+  H = (int)(off_buf->data_size / off_buf->stride);
+  if (W != mask->data_w() || H != mask->data_h()) {
+    Fl_RGB_Image *copy = (Fl_RGB_Image*)mask->copy(W, H);
+    mask = copy;
+    using_copy = true;
+  }
+  shape_data_->mask_pattern_ = Fl_Cairo_Graphics_Driver::calc_cairo_mask(mask);
+  //duplicate current offscreen content to new cairo_t* shape_data_->bg_cr
+  int width, height;
+  printable_rect(&width, &height);
+  struct Fl_Wayland_Graphics_Driver::draw_buffer *off_ =
+  (struct Fl_Wayland_Graphics_Driver::draw_buffer*)calloc(1,
+                                                          sizeof(struct Fl_Wayland_Graphics_Driver::draw_buffer));
+  Fl_Wayland_Graphics_Driver::cairo_init(off_, W, H,
+                                         cairo_format_stride_for_width(CAIRO_FORMAT_RGB24, W),
+                                         CAIRO_FORMAT_RGB24);
+  cairo_set_user_data(off_->cairo_, &Fl_Wayland_Graphics_Driver::key, off_, NULL);
+  shape_data_->bg_cr = off_->cairo_;
+  memcpy(off_->buffer, off_buf->buffer, off_buf->data_size);
+  shape_data_->scale = double(width) / W;
+  if (using_copy) delete mask;
+}