Fix for issue #155 - continued

The issue lies in details how floating point scaled coordinates are converted
to integer values and its impact on the drawing of large SVG images.
This commit fixes the X11 platform.
The macOS platform is immune because drawing uses floating point
coordinates.
The Windows platform still needs fixing.

1 files changed, 9 insertions, 4 deletions

diff --git a/src/Fl_Graphics_Driver.cxx b/src/Fl_Graphics_Driver.cxx
index 7b46d691e..c5cd9d6c5 100644
--- a/src/Fl_Graphics_Driver.cxx
+++ b/src/Fl_Graphics_Driver.cxx
@@ -29,6 +29,7 @@
 #include <FL/Fl_Image_Surface.H>
 #include <FL/math.h>
 #include <FL/platform.H>
+#include <FL/Fl_SVG_Image.H>
 
 FL_EXPORT Fl_Graphics_Driver *fl_graphics_driver; // the current driver of graphics operations
 
@@ -201,7 +202,7 @@ unsigned Fl_Graphics_Driver::font_desc_size() {
 /** Converts \p width and \p height from FLTK units to drawing units.
  The conversion performed consists in multiplying \p width and \p height by
  scale() and in slightly modifying that to help support tiled images. */
-void Fl_Graphics_Driver::cache_size(int &width, int &height)
+void Fl_Graphics_Driver::cache_size(Fl_Image *img, int &width, int &height)
 {
   if ( int(scale()) == scale() ) {
     width  = width * scale();
@@ -210,6 +211,10 @@ void Fl_Graphics_Driver::cache_size(int &width, int &height)
     width  = (width+1) * scale();
     height = (height+1) * scale();
   }
+  if (img->d() == 4 && ((Fl_RGB_Image*)img)->as_svg_image()) { // check for SVG image
+    Fl_SVG_Image *svg = (Fl_SVG_Image*)img;
+    svg->cache_size(width, height);
+  }
 }
 
 /** Draws an Fl_Pixmap object using this graphics driver.
@@ -223,7 +228,7 @@ void Fl_Graphics_Driver::draw_pixmap(Fl_Pixmap *pxm, int XP, int YP, int WP, int
   }
   // to allow rescale at runtime
   int w2=pxm->w(), h2=pxm->h();
-  cache_size(w2, h2); // after this, w2 x h2 is size of desired cached image
+  cache_size(pxm, w2, h2); // after this, w2 x h2 is size of desired cached image
   int *pw, *ph;
   cache_w_h(pxm, pw, ph); // after this, *pw x *ph is current size of cached form of bitmap
   if (*id(pxm) && (*pw != w2 || *ph != h2)) {
@@ -256,7 +261,7 @@ void Fl_Graphics_Driver::draw_bitmap(Fl_Bitmap *bm, int XP, int YP, int WP, int
     return;
   }
   int w2 = bm->w(), h2 = bm->h();
-  cache_size(w2, h2); // after this, w2 x h2 is size of desired cached image
+  cache_size(bm, w2, h2); // after this, w2 x h2 is size of desired cached image
   int *pw, *ph;
   cache_w_h(bm, pw, ph); // after this, *pw x *ph is current size of cached form of bitmap
   if (*id(bm) && (*pw != w2 || *ph != h2)) {
@@ -296,7 +301,7 @@ void Fl_Graphics_Driver::draw_rgb(Fl_RGB_Image *img, int XP, int YP, int WP, int
   int w2, h2, *pw, *ph;
   if (need_scaled_drawing) {
     w2 = img->w(); h2 = img->h();
-    cache_size(w2, h2);
+    cache_size(img, w2, h2);
   } else {
     w2 = img->data_w(); h2 = img->data_h();
   } // after this, w2 x h2 is desired cached image size