diff options
| -rw-r--r-- | FL/Fl_Image.H | 17 | ||||
| -rw-r--r-- | src/Fl_Image.cxx | 95 |
2 files changed, 98 insertions, 14 deletions
diff --git a/FL/Fl_Image.H b/FL/Fl_Image.H index edba4fe29..7a1f4fdbc 100644 --- a/FL/Fl_Image.H +++ b/FL/Fl_Image.H @@ -154,6 +154,14 @@ class FL_EXPORT Fl_Image { virtual void uncache(); }; +/// \enum Fl_RGB_Scaling +/// The scaling algorithm to use. +/// +enum Fl_RGB_Scaling { + FL_SCALING_NEAREST = 0, + FL_SCALING_BILINEAR +}; + /** The Fl_RGB_Image class supports caching and drawing of full-color images with 1 to 4 channels of color information. @@ -170,6 +178,7 @@ class FL_EXPORT Fl_RGB_Image : public Fl_Image { friend class Fl_GDI_Graphics_Driver; friend class Fl_Xlib_Graphics_Driver; static size_t max_size_; + static Fl_RGB_Scaling scaling_; public: const uchar *array; @@ -230,6 +239,14 @@ public: \sa void Fl_RGB_Image::max_size(size_t) */ static size_t max_size() {return max_size_;} + + /** Sets the currently used scaling method. + Applies to all RGB images, defaults to FL_SCALING_NEAREST. + */ + static void scaling(Fl_RGB_Scaling); + + /** Returns the currently used scaling method. */ + static Fl_RGB_Scaling scaling(); }; #endif // !Fl_Image_H diff --git a/src/Fl_Image.cxx b/src/Fl_Image.cxx index c27d90b63..7d1643f56 100644 --- a/src/Fl_Image.cxx +++ b/src/Fl_Image.cxx @@ -164,6 +164,7 @@ Fl_Image::measure(const Fl_Label *lo, // I - Label // RGB image class... // size_t Fl_RGB_Image::max_size_ = ~((size_t)0); +Fl_RGB_Scaling Fl_RGB_Image::scaling_ = FL_SCALING_NEAREST; int fl_convert_pixmap(const char*const* cdata, uchar* out, Fl_Color bg); @@ -260,25 +261,84 @@ Fl_Image *Fl_RGB_Image::copy(int W, int H) { new_image = new Fl_RGB_Image(new_array, W, H, d()); new_image->alloc_array = 1; - // Scale the image using a nearest-neighbor algorithm... - for (dy = H, sy = 0, yerr = H, new_ptr = new_array; dy > 0; dy --) { - for (dx = W, xerr = W, old_ptr = array + sy * line_d; dx > 0; dx --) { - for (c = 0; c < d(); c ++) *new_ptr++ = old_ptr[c]; + if (scaling_ == FL_SCALING_NEAREST) { + // Scale the image using a nearest-neighbor algorithm... + for (dy = H, sy = 0, yerr = H, new_ptr = new_array; dy > 0; dy --) { + for (dx = W, xerr = W, old_ptr = array + sy * line_d; dx > 0; dx --) { + for (c = 0; c < d(); c ++) *new_ptr++ = old_ptr[c]; - old_ptr += xstep; - xerr -= xmod; + old_ptr += xstep; + xerr -= xmod; - if (xerr <= 0) { - xerr += W; - old_ptr += d(); + if (xerr <= 0) { + xerr += W; + old_ptr += d(); + } + } + + sy += ystep; + yerr -= ymod; + if (yerr <= 0) { + yerr += H; + sy ++; } } + } else { + // Bilinear scaling + const float xscale = (w() - 1) / (float) W; + const float yscale = (h() - 1) / (float) H; + for (dy = 0; dy < H; dy++) { + float oldy = dy * yscale; + if (oldy >= h()) + oldy = h() - 1; + const float yfract = oldy - (unsigned) oldy; + + for (dx = 0; dx < W; dx++) { + new_ptr = new_array + dy * W * d() + dx * d(); + + float oldx = dx * xscale; + if (oldx >= w()) + oldx = w() - 1; + const float xfract = oldx - (unsigned) oldx; + + const unsigned leftx = oldx; + const unsigned lefty = oldy; + const unsigned rightx = oldx + 1 >= w() ? oldx : oldx + 1; + const unsigned righty = oldy; + const unsigned dleftx = oldx; + const unsigned dlefty = oldy + 1 >= h() ? oldy : oldy + 1; + const unsigned drightx = rightx; + const unsigned drighty = dlefty; + + uchar left[4], right[4], downleft[4], downright[4]; + memcpy(left, array + lefty * line_d + leftx * d(), d()); + memcpy(right, array + righty * line_d + rightx * d(), d()); + memcpy(downleft, array + dlefty * line_d + dleftx * d(), d()); + memcpy(downright, array + drighty * line_d + drightx * d(), d()); + + // TODO: how to check if it's premultiplied alpha? + int i; + if (d() == 4) { + for (i = 0; i < 3; i++) { + left[i] *= left[3] / 255.0f; + right[i] *= right[3] / 255.0f; + downleft[i] *= downleft[3] / 255.0f; + downright[i] *= downright[3] / 255.0f; + } + } + + const float leftf = 1 - xfract; + const float rightf = xfract; + const float upf = 1 - yfract; + const float downf = yfract; - sy += ystep; - yerr -= ymod; - if (yerr <= 0) { - yerr += H; - sy ++; + for (i = 0; i < d(); i++) { + new_ptr[i] = (left[i] * leftf + + right[i] * rightf) * upf + + (downleft[i] * leftf + + downright[i] * rightf) * downf; + } + } } } @@ -614,6 +674,13 @@ void Fl_RGB_Image::label(Fl_Menu_Item* m) { m->label(_FL_IMAGE_LABEL, (const char*)this); } +void Fl_RGB_Image::scaling(Fl_RGB_Scaling method) { + scaling_ = method; +} + +Fl_RGB_Scaling Fl_RGB_Image::scaling() { + return scaling_; +} // // End of "$Id$". |