New member function Fl_Quartz_Graphics_Driver::draw_CGImage() used internally for all image drawing.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3-porting@11165 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

3 files changed, 42 insertions, 18 deletions

diff --git a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx
index a8ed4185e..81d916819 100644
--- a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx
+++ b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.cxx
@@ -65,11 +65,8 @@ void Fl_Quartz_Graphics_Driver::copy_offscreen(int x,int y,int w,int h,Fl_Offscr
   CGDataProviderRef src_bytes = CGDataProviderCreateWithData( src, data, sw*sh*4, bmProviderRelease);
   CGImageRef img = CGImageCreate( sw, sh, 8, 4*8, 4*sw, lut, alpha,
                                  src_bytes, 0L, false, kCGRenderingIntentDefault);
-  // fl_push_clip();
-  CGRect rect = CGRectMake(x, y, w, h);
-  Fl_X::q_begin_image(rect, srcx, srcy, sw, sh);
-  CGContextDrawImage(fl_gc, rect, img);
-  Fl_X::q_end_image();
+  draw_CGImage(img, x, y, w, h, srcx, srcy,  sw, sh);
+
   CGImageRelease(img);
   CGColorSpaceRelease(lut);
   CGDataProviderRelease(src_bytes);
@@ -153,7 +150,42 @@ void fl_end_offscreen() {
 
 /** @} */
 
-
+void Fl_Quartz_Graphics_Driver::draw_CGImage(CGImageRef cgimg, int x, int y, int w, int h, int srcx, int srcy, int sw, int sh)
+{
+  CGRect rect = CGRectMake(x, y, w, h);
+  CGContextSaveGState(fl_gc);
+  CGContextClipToRect(fl_gc, CGRectOffset(rect, -0.5, -0.5 ));
+  // move graphics context to origin of vertically reversed image
+  // The 0.5 here cancels the 0.5 offset present in Quartz graphics contexts.
+  // Thus, image and surface pixels are in phase if there's no scaling.
+  CGContextTranslateCTM(fl_gc, rect.origin.x - srcx - 0.5, rect.origin.y - srcy + sh - 0.5);
+  CGContextScaleCTM(fl_gc, 1, -1);
+  CGAffineTransform at = CGContextGetCTM(fl_gc);
+  if (at.a == at.d && at.b == 0 && at.c == 0) { // proportional scaling, no rotation
+    // We handle x2 and /2 scalings that occur when drawing to
+    // a double-resolution bitmap, and when drawing a double-resolution bitmap to display.
+    bool doit = false;
+    // phase image with display pixels
+    CGFloat deltax = 0, deltay = 0;
+    if (at.a == 2) { // make .tx and .ty have even values
+      deltax = (at.tx/2 - round(at.tx/2));
+      deltay = (at.ty/2 - round(at.ty/2));
+      doit = true;
+    } else if (at.a == 0.5) {
+      doit = true;
+      if (Fl_Display_Device::high_resolution()) { // make .tx and .ty have int or half-int values
+        deltax = (at.tx*2 - round(at.tx*2));
+        deltay = (at.ty*2 - round(at.ty*2));
+      } else { // make .tx and .ty have integral values
+        deltax = (at.tx - round(at.tx))*2;
+        deltay = (at.ty - round(at.ty))*2;
+      }
+    }
+    if (doit) CGContextTranslateCTM(fl_gc, -deltax, -deltay);
+  }
+  CGContextDrawImage(fl_gc, CGRectMake(0, 0, sw, sh), cgimg);
+  CGContextRestoreGState(fl_gc);
+}
 
 //
 // End of "$Id$".
diff --git a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.h b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.h
index 5d2c0ccb0..93fbbfeb3 100644
--- a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.h
+++ b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver.h
@@ -64,6 +64,7 @@ public:
   static Fl_Offscreen create_offscreen_with_alpha(int w, int h);
 #endif
   void copy_offscreen(int x, int y, int w, int h, Fl_Offscreen pixmap, int srcx, int srcy);
+  void draw_CGImage(CGImageRef cgimg, int x, int y, int w, int h, int srcx, int srcy, int sw, int sh);
 protected:
   // --- implementation is in src/fl_rect.cxx which includes src/cfg_gfx/quartz_rect.cxx
   void point(int x, int y);
diff --git a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver_image.cxx b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver_image.cxx
index 868d81ec8..c15e767a2 100644
--- a/src/drivers/Quartz/Fl_Quartz_Graphics_Driver_image.cxx
+++ b/src/drivers/Quartz/Fl_Quartz_Graphics_Driver_image.cxx
@@ -90,10 +90,7 @@ static void innards(const uchar *buf, int X, int Y, int W, int H,
                             src, 0L, false, kCGRenderingIntentDefault);
   // draw the image into the destination context
   if (img) {
-    CGRect rect = CGRectMake( X, Y,  W, H);
-    Fl_X::q_begin_image(rect, 0, 0, W, H);
-    CGContextDrawImage(fl_gc, rect, img);
-    Fl_X::q_end_image();
+    ((Fl_Quartz_Graphics_Driver*)fl_graphics_driver)->draw_CGImage(img, X,Y,W,H, 0,0,W,H);
     // release all allocated resources
     CGImageRelease(img);
   }
@@ -170,10 +167,7 @@ void Fl_Quartz_Graphics_Driver::draw(Fl_Bitmap *bm, int XP, int YP, int WP, int
     return;
   }
   if (bm->id_ && fl_gc) {
-    CGRect rect = { { (CGFloat)X, (CGFloat)Y }, { (CGFloat)W, (CGFloat)H } };
-    Fl_X::q_begin_image(rect, cx, cy, bm->w(), bm->h());
-    CGContextDrawImage(fl_gc, rect, (CGImageRef)bm->id_);
-    Fl_X::q_end_image();
+    draw_CGImage((CGImageRef)bm->id_, X,Y,W,H, cx, cy, bm->w(), bm->h());
   }
 }
 
@@ -249,10 +243,7 @@ void Fl_Quartz_Graphics_Driver::draw(Fl_RGB_Image *img, int XP, int YP, int WP,
       CGColorSpaceRelease(lut);
       CGDataProviderRelease(src);
     }
-    CGRect rect = CGRectMake(X, Y, W, H);
-    Fl_X::q_begin_image(rect, cx, cy, img->w(), img->h());
-    CGContextDrawImage(fl_gc, rect, (CGImageRef)img->id_);
-    Fl_X::q_end_image();
+    draw_CGImage((CGImageRef)img->id_, X,Y,W,H, cx,cy, img->w(), img->h());
   }
 }