Added Fl_Shared_Image::scale(width, height) to support scaled image drawing (STR #3185).

Useful for printing, PostScript or PDF output, or retina displays.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10615 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

4 files changed, 228 insertions, 21 deletions

diff --git a/src/Fl_Image.cxx b/src/Fl_Image.cxx
index 3df1efde4..e4e88478e 100644
--- a/src/Fl_Image.cxx
+++ b/src/Fl_Image.cxx
@@ -3,7 +3,7 @@
 //
 // Image drawing code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2014 by Bill Spitzak and others.
+// Copyright 1998-2015 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -548,6 +548,21 @@ static int start(Fl_RGB_Image *img, int XP, int YP, int WP, int HP, int w, int h
   return 0;
 }
 
+/** Draws an Fl_RGB_Image scaled to width \p W & height \p H with top-left corner at \em X,Y
+ \return zero when the graphics driver doesn't implement scaled drawing, non-zero if it does implement it.
+ */
+int Fl_Graphics_Driver::draw_scaled(Fl_RGB_Image *img, int X, int Y, int W, int H) {
+  return 0;
+}
+
+/** Draws an Fl_Pixmap scaled to width \p W & height \p H with top-left corner at \em X,Y
+ \return zero when the graphics driver doesn't implement scaled drawing, non-zero if it does implement it.
+ */
+int Fl_Graphics_Driver::draw_scaled(Fl_Pixmap *img, int X, int Y, int W, int H) {
+  return 0;
+}
+
+
 #ifdef __APPLE__
 static void imgProviderReleaseData (void *info, const void *data, size_t size)
 {
@@ -612,7 +627,40 @@ void Fl_Quartz_Graphics_Driver::draw(Fl_RGB_Image *img, int XP, int YP, int WP,
   }
 }
 
+int Fl_Quartz_Graphics_Driver::draw_scaled(Fl_RGB_Image *img, int XP, int YP, int WP, int HP) {
+  int X, Y, W, H;
+  fl_clip_box(XP,YP,WP,HP,X,Y,W,H); // X,Y,W,H will give the unclipped area of XP,YP,WP,HP
+  if (W == 0 || H == 0) return 1;
+  fl_push_no_clip(); // remove the FLTK clip that can't be rescaled
+  CGContextSaveGState(fl_gc);
+  CGContextClipToRect(fl_gc, CGRectMake(X, Y, W, H)); // this clip path will be rescaled & translated
+  CGContextTranslateCTM(fl_gc, XP, YP);
+  CGContextScaleCTM(fl_gc, float(WP)/img->w(), float(HP)/img->h());
+  draw(img, 0, 0, img->w(), img->h(), 0, 0);
+  CGContextRestoreGState(fl_gc);
+  fl_pop_clip(); // restore FLTK's clip
+  return 1;
+}
+
 #elif defined(WIN32)
+static Fl_Offscreen build_id(Fl_RGB_Image *img, void **pmask)
+{
+  Fl_Offscreen offs = fl_create_offscreen(img->w(), img->h());
+  if ((img->d() == 2 || img->d() == 4) && fl_can_do_alpha_blending()) {
+    fl_begin_offscreen(offs);
+    fl_draw_image(img->array, 0, 0, img->w(), img->h(), img->d()|FL_IMAGE_WITH_ALPHA, img->ld());
+    fl_end_offscreen();
+  } else {
+    fl_begin_offscreen(offs);
+    fl_draw_image(img->array, 0, 0, img->w(), img->h(), img->d(), img->ld());
+    fl_end_offscreen();
+    if (img->d() == 2 || img->d() == 4) {
+      *pmask = fl_create_alphamask(img->w(), img->h(), img->d(), img->ld(), img->array);
+    }
+  }
+  return offs;
+}
+
 void Fl_GDI_Graphics_Driver::draw(Fl_RGB_Image *img, int XP, int YP, int WP, int HP, int cx, int cy) {
   int X, Y, W, H;
   // Don't draw an empty image...
@@ -623,21 +671,7 @@ void Fl_GDI_Graphics_Driver::draw(Fl_RGB_Image *img, int XP, int YP, int WP, int
   if (start(img, XP, YP, WP, HP, img->w(), img->h(), cx, cy, X, Y, W, H)) {
     return;
   }
-  if (!img->id_) {
-    img->id_ = fl_create_offscreen(img->w(), img->h());
-    if ((img->d() == 2 || img->d() == 4) && fl_can_do_alpha_blending()) {
-      fl_begin_offscreen((Fl_Offscreen)img->id_);
-      fl_draw_image(img->array, 0, 0, img->w(), img->h(), img->d()|FL_IMAGE_WITH_ALPHA, img->ld());
-      fl_end_offscreen();
-    } else {
-      fl_begin_offscreen((Fl_Offscreen)img->id_);
-      fl_draw_image(img->array, 0, 0, img->w(), img->h(), img->d(), img->ld());
-      fl_end_offscreen();
-      if (img->d() == 2 || img->d() == 4) {
-        img->mask_ = fl_create_alphamask(img->w(), img->h(), img->d(), img->ld(), img->array);
-      }
-    }
-  }
+  if (!img->id_) img->id_ = build_id(img, &(img->mask_));
   if (img->mask_) {
     HDC new_gc = CreateCompatibleDC(fl_gc);
     int save = SaveDC(new_gc);
@@ -654,6 +688,20 @@ void Fl_GDI_Graphics_Driver::draw(Fl_RGB_Image *img, int XP, int YP, int WP, int
   }
 }
 
+int Fl_GDI_Printer_Graphics_Driver::draw_scaled(Fl_RGB_Image *img, int XP, int YP, int WP, int HP) {
+  XFORM old_tr, tr;
+  GetWorldTransform(fl_gc, &old_tr); // storing old transform
+  tr.eM11 = float(WP)/float(img->w());
+  tr.eM22 = float(HP)/float(img->h());
+  tr.eM12 = tr.eM21 = 0;
+  tr.eDx =  XP;
+  tr.eDy =  YP;
+  ModifyWorldTransform(fl_gc, &tr, MWT_LEFTMULTIPLY);
+  Fl_GDI_Graphics_Driver::draw(img, 0, 0, img->w(), img->h(), 0, 0);
+  SetWorldTransform(fl_gc, &old_tr);
+return 1;
+}
+
 #else
 void Fl_Xlib_Graphics_Driver::draw(Fl_RGB_Image *img, int XP, int YP, int WP, int HP, int cx, int cy) {
   int X, Y, W, H;
diff --git a/src/Fl_Pixmap.cxx b/src/Fl_Pixmap.cxx
index 8064979dd..2bb776b6b 100644
--- a/src/Fl_Pixmap.cxx
+++ b/src/Fl_Pixmap.cxx
@@ -135,6 +135,21 @@ void Fl_Quartz_Graphics_Driver::draw(Fl_Pixmap *pxm, int XP, int YP, int WP, int
   copy_offscreen(X, Y, W, H, (Fl_Offscreen)pxm->id_, cx, cy);
 }
 
+int Fl_Quartz_Graphics_Driver::draw_scaled(Fl_Pixmap *img, int XP, int YP, int WP, int HP) {
+  int X, Y, W, H;
+  fl_clip_box(XP,YP,WP,HP,X,Y,W,H); // X,Y,W,H will give the unclipped area of XP,YP,WP,HP
+  if (W == 0 || H == 0) return 1;
+  fl_push_no_clip(); // remove the FLTK clip that can't be rescaled
+  CGContextSaveGState(fl_gc);
+  CGContextClipToRect(fl_gc, CGRectMake(X, Y, W, H)); // this clip path will be rescaled & translated
+  CGContextTranslateCTM(fl_gc, XP, YP);
+  CGContextScaleCTM(fl_gc, float(WP)/img->w(), float(HP)/img->h());
+  draw(img, 0, 0, img->w(), img->h(), 0, 0);
+  CGContextRestoreGState(fl_gc);
+  fl_pop_clip(); // restore FLTK's clip
+  return 1;
+}
+
 #elif defined(WIN32)
 void Fl_GDI_Graphics_Driver::draw(Fl_Pixmap *pxm, int XP, int YP, int WP, int HP, int cx, int cy) {
   int X, Y, W, H;
@@ -181,6 +196,20 @@ void Fl_GDI_Printer_Graphics_Driver::draw(Fl_Pixmap *pxm, int XP, int YP, int WP
   }
 }
 
+int Fl_GDI_Printer_Graphics_Driver::draw_scaled(Fl_Pixmap *img, int XP, int YP, int WP, int HP) {
+  XFORM old_tr, tr;
+  GetWorldTransform(fl_gc, &old_tr); // storing old transform
+  tr.eM11 = float(WP)/float(img->w());
+  tr.eM22 = float(HP)/float(img->h());
+  tr.eM12 = tr.eM21 = 0;
+  tr.eDx =  XP;
+  tr.eDy =  YP;
+  ModifyWorldTransform(fl_gc, &tr, MWT_LEFTMULTIPLY);
+  draw(img, 0, 0, img->w(), img->h(), 0, 0);
+  SetWorldTransform(fl_gc, &old_tr);
+}
+
+
 #else // Xlib
 void Fl_Xlib_Graphics_Driver::draw(Fl_Pixmap *pxm, int XP, int YP, int WP, int HP, int cx, int cy) {
   int X, Y, W, H;
diff --git a/src/Fl_Shared_Image.cxx b/src/Fl_Shared_Image.cxx
index 2289ccdb4..4a05a46ef 100644
--- a/src/Fl_Shared_Image.cxx
+++ b/src/Fl_Shared_Image.cxx
@@ -3,7 +3,7 @@
 //
 // Shared image code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2010 by Bill Spitzak and others.
+// Copyright 1998-2015 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -25,7 +25,8 @@
 #include <FL/Fl_Shared_Image.H>
 #include <FL/Fl_XBM_Image.H>
 #include <FL/Fl_XPM_Image.H>
-
+#include <FL/Fl_Preferences.H>
+#include <FL/fl_draw.H>
 
 //
 // Global class vars...
@@ -89,6 +90,9 @@ Fl_Shared_Image::Fl_Shared_Image() : Fl_Image(0,0,0) {
   original_    = 0;
   image_       = 0;
   alloc_image_ = 0;
+#if FLTK_ABI_VERSION >= 10304
+  scaled_image_= 0;
+#endif
 }
 
 
@@ -109,6 +113,9 @@ Fl_Shared_Image::Fl_Shared_Image(const char *n,		// I - Filename
   image_       = img;
   alloc_image_ = !img;
   original_    = 1;
+#if FLTK_ABI_VERSION >= 10304
+  scaled_image_= 0;
+#endif
 
   if (!img) reload();
   else update();
@@ -170,6 +177,9 @@ Fl_Shared_Image::update() {
 Fl_Shared_Image::~Fl_Shared_Image() {
   if (name_) delete[] (char *)name_;
   if (alloc_image_) delete image_;
+#if FLTK_ABI_VERSION >= 10304
+  delete scaled_image_;
+#endif
 }
 
 
@@ -317,13 +327,95 @@ Fl_Shared_Image::desaturate() {
 //
 // 'Fl_Shared_Image::draw()' - Draw a shared image...
 //
-
-void
-Fl_Shared_Image::draw(int X, int Y, int W, int H, int cx, int cy) {
+void Fl_Shared_Image::draw(int X, int Y, int W, int H, int cx, int cy) {
+#if FLTK_ABI_VERSION >= 10304
+  if (!image_) {
+    Fl_Image::draw(X, Y, W, H, cx, cy);
+    return;
+  }
+  if (w() == image_->w() && h() == image_->h()) {
+    image_->draw(X, Y, W, H, cx, cy);
+    return;
+  }
+  fl_push_clip(X, Y, W, H);
+  int use_scaled_image = 0, done;
+  if (image_->d() == 0) { // handles Fl_Bitmap
+    use_scaled_image = 1;
+  }
+  else if (image_->count() >= 2) { // handles Fl_Pixmap
+    done = fl_graphics_driver->draw_scaled((Fl_Pixmap*)image_, X-cx, Y-cy, w(), h());
+    if (done == 0) use_scaled_image = 1;
+  }
+  else { // handles Fl_RGB_Image
+    done = fl_graphics_driver->draw_scaled((Fl_RGB_Image*)image_, X-cx, Y-cy, w(), h());
+    if (done == 0) use_scaled_image = 1;
+  }
+  if (use_scaled_image) {
+    if (scaled_image_ && (scaled_image_->w() != w() || scaled_image_->h() != h())) {
+      delete scaled_image_;
+      scaled_image_ = NULL;
+    }
+    if (!scaled_image_) {
+      Fl_RGB_Scaling previous = RGB_scaling();
+      RGB_scaling(scaling_algorithm_); // useless but no harm if image_ is not an Fl_RGB_Image
+      scaled_image_ = image_->copy(w(), h());
+      RGB_scaling(previous);
+    }
+    scaled_image_->draw(X-cx, Y-cy, scaled_image_->w(), scaled_image_->h(), 0, 0);
+  }
+  fl_pop_clip();
+#else
   if (image_) image_->draw(X, Y, W, H, cx, cy);
   else Fl_Image::draw(X, Y, W, H, cx, cy);
+#endif // FLTK_ABI_VERSION
 }
 
+/** Sets the drawing size of the shared image.
+ This function gives the shared image its own size, independently from the size of the original image
+ that is typically larger than the shared image.
+ This can be useful to draw a shared image on a drawing surface whose resolution is higher
+ than the drawing unit for this surface. Examples of such drawing surfaces: laser printers,
+ PostScript files, PDF printers, retina displays on Apple hardware.
+
+ \param width,height   maximum width and height (in drawing units) to use when drawing the shared image
+ \param proportional   if not null, keep the width and height of the shared image proportional to those of its original image
+ \param can_expand  if null, the width and height of the shared image will not exceed those of the original image
+ 
+ \version 1.3.4 and requires compiling with FLTK_ABI_VERSION = 10304
+ 
+ Example code: scale an image to fit in a box
+ \code
+ Fl_Box *b = ...  // a box
+ Fl_Shared_Image *shared = Fl_Shared_Image::get("/path/to/picture.jpeg"); // read a picture file
+ b->image(shared); // use the shared image as the box image
+ b->align(FL_ALIGN_INSIDE | FL_ALIGN_CENTER | FL_ALIGN_CLIP); // the image is to be drawn centered in the box
+ shared->scale(b->w(), b->h(), 1); // set the drawing size of the shared image to the size of the box
+ \endcode
+ */
+void Fl_Shared_Image::scale(int width, int height, int proportional, int can_expand)
+{
+#if FLTK_ABI_VERSION >= 10304
+  w(width);
+  h(height);
+  if (!image_) return;
+  float fw = image_->w() / float(width);
+  float fh = image_->h() / float(height);
+  if (proportional) {
+    if (fh > fw) fw = fh;
+    else fh = fw;
+  }
+  if (!can_expand) {
+    if (fw < 1) fw = 1;
+    if (fh < 1) fh = 1;
+  }
+  w(image_->w() / fw);
+  h(image_->h() / fh);
+#endif
+}
+
+
+Fl_RGB_Scaling Fl_Shared_Image::scaling_algorithm_ = FL_RGB_SCALING_BILINEAR;
+
 
 //
 // 'Fl_Shared_Image::uncache()' - Uncache the shared image...
@@ -408,6 +500,18 @@ Fl_Shared_Image* Fl_Shared_Image::get(const char *n, int W, int H) {
   return temp;
 }
 
+/** Builds a shared image from a pre-existing Fl_RGB_Image
+ \param rgb  an Fl_RGB_Image used to build a new shared image.
+ \param own_it 1 if the shared image should delete \p rgb when it is itself deleted, 0 otherwise
+ \version 1.3.4
+ */
+Fl_Shared_Image *Fl_Shared_Image::get(Fl_RGB_Image *rgb, int own_it)
+{
+  Fl_Shared_Image *shared = new Fl_Shared_Image(Fl_Preferences::newUUID(), rgb);
+  shared->alloc_image_ = own_it;
+  shared->add();
+  return shared;
+}
 
 
 /** Adds a shared image handler, which is basically a test function for adding new formats */
diff --git a/src/ps_image.cxx b/src/ps_image.cxx
index 3939a7511..ca71121b9 100644
--- a/src/ps_image.cxx
+++ b/src/ps_image.cxx
@@ -602,6 +602,32 @@ void Fl_PostScript_Graphics_Driver::draw(Fl_RGB_Image * rgb,int XP, int YP, int
   mask=0;
 }
 
+int Fl_PostScript_Graphics_Driver::draw_scaled(Fl_RGB_Image *rgb, int XP, int YP, int WP, int HP){
+  int X, Y, W, H;
+  clip_box(XP,YP,WP,HP,X,Y,W,H); // X,Y,W,H will give the unclipped area of XP,YP,WP,HP
+  if (W == 0 || H == 0) return 1;
+  push_no_clip(); // remove the FLTK clip that can't be rescaled
+  clocale_printf("%d %d %i %i CL\n", X, Y, W, H);
+  clocale_printf("GS %d %d TR  %f %f SC GS\n", XP, YP, float(WP)/rgb->w(), float(HP)/rgb->h());
+  draw(rgb, 0, 0, rgb->w(), rgb->h(), 0, 0);
+  clocale_printf("GR GR\n");
+  pop_clip(); // restore FLTK's clip
+  return 1;
+}
+
+int Fl_PostScript_Graphics_Driver::draw_scaled(Fl_Pixmap *img, int XP, int YP, int WP, int HP){
+  int X, Y, W, H;
+  clip_box(XP,YP,WP,HP,X,Y,W,H); // X,Y,W,H will give the unclipped area of XP,YP,WP,HP
+  if (W == 0 || H == 0) return 1;
+  push_no_clip(); // remove the FLTK clip that can't be rescaled
+  clocale_printf("%d %d %i %i CL\n", X, Y, W, H);
+  clocale_printf("GS %d %d TR  %f %f SC GS\n", XP, YP, float(WP)/img->w(), float(HP)/img->h());
+  draw(img, 0, 0, img->w(), img->h(), 0, 0);
+  clocale_printf("GR GR\n");
+  pop_clip(); // restore FLTK's clip
+  return 1;
+}
+
 void Fl_PostScript_Graphics_Driver::draw(Fl_Bitmap * bitmap,int XP, int YP, int WP, int HP, int cx, int cy){
   const uchar  * di = bitmap->array;
   int w,h;