SVG support: draw images at full screen resolution also when there are several pixels per graphical unit, as with Apple retina displays.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12456 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 19 insertions, 2 deletions

diff --git a/src/Fl_SVG_Image.cxx b/src/Fl_SVG_Image.cxx
index 91be0c70d..4e4645d3f 100644
--- a/src/Fl_SVG_Image.cxx
+++ b/src/Fl_SVG_Image.cxx
@@ -22,6 +22,8 @@
 
 #include <FL/Fl_SVG_Image.H>
 #include <FL/fl_utf8.h>
+#include <FL/fl_draw.H>
+#include <FL/Fl_Screen_Driver.H>
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -182,8 +184,23 @@ void Fl_SVG_Image::resize(int width, int height) {
 
 
 void Fl_SVG_Image::draw(int X, int Y, int W, int H, int cx, int cy) {
-  resize(w(), h());
-  Fl_RGB_Image::draw(X, Y, W, H, cx, cy);
+  static float f = Fl::screen_driver()->retina_factor();
+  int w1 = w(), h1 = h();
+  /* When f > 1, there may be several pixels per drawing unit in an area
+   of size w() x h() of the display. This occurs, e.g., with Apple retina displays.
+   The SVG is rasterized to the area dimension in pixels. The image is then drawn
+   scaled to its size expressed in drawing units. With this procedure,
+   the SVG image is drawn using the full resolution of the display.
+   */
+  resize(f*w(), f*h());
+  if (f == 1) {
+    Fl_RGB_Image::draw(X, Y, W, H, cx, cy);
+  } else {
+    bool need_clip = (cx || cy || W != w1 || H != h1);
+    if (need_clip) fl_push_clip(X, Y, W, H);
+    fl_graphics_driver->draw_scaled(this, X-cx, Y-cy, w1, h1);
+    if (need_clip) fl_pop_clip();
+  }
 }