fltk/FL/Fl_Image.H

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//
// "$Id$"
//
// Image header file for the Fast Light Tool Kit (FLTK).
//
Introduce HiDPI + rescaling support for the X11 platform (+ partial support for WIN32) Corresponds to STR #3320 1) HiDPI support consists in detecting the adequate scaling factor for the screen on which FLTK maps a window, and scaling all FLTK units by this factor. FLTK tries to detect the correct value of this factor at startup (see more details below). Environment variable FLTK_SCALING_FACTOR can also be used to set this value. 2) Rescaling support consists in changing the scaling factor of all FLTK windows in reply to ctrl/+/-/0/ keystrokes. More details for the various platforms : - X11: Support is very advanced. Some details need still to be improved. Automatic detection of the correct starting value of the scaling factor works well with the gnome desktop. The present code contains no support for this on other desktops. FLTK_SCALING_FACTOR provides a workaround. -WIN32: Support is incomplete at this point, although many test applications have partial or complete HiDPI and scaling support. The current value of the system's scaling factor is correctly detected at application startup. Apps respond to changes of this value in real time. Support needs to define the FLTK_HIDPI_SUPPORT preprocessor variable at compile time. This way, standard builds produce a code with the default WIN32 HiDPI support, that is, where all graphics goes to an internal buffer that gets enlarged by the system and then mapped to the HiDPI display. To experiment with (or develop) the new HiDPI support requires a modified build procedure in which FLTK_HIDPI_SUPPORT is defined at compile time. When the support will be complete, the requirement for the definition of this preprocessor variable will be removed. The present commit contains support for a single scaling factor. Eventually, per-screen scaling factors should be implemented, as done for X11. - MacOS: this commit does not give new HiDPI for this platform. Eventually, window rescaling in reply to command/+/-/0/ is desirable. Per-screen scaling factor makes no sense on this platform because the OS itself takes care of the difference between the resolutions of traditional and retina displays. git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12239 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
2017-05-17 14:54:18 +03:00
// Copyright 1998-2017 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
// file is missing or damaged, see the license at:
//
// http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
/** \file
Fl_Image, Fl_RGB_Image classes. */
#ifndef Fl_Image_H
#define Fl_Image_H
#include "Enumerations.H"
#include <stdlib.h>
#include "Fl_Widget.H" // for fl_uintptr_t
class Fl_Widget;
class Fl_Pixmap;
struct Fl_Menu_Item;
struct Fl_Label;
class Fl_RGB_Image;
/** \enum Fl_RGB_Scaling
The scaling algorithm to use for RGB images.
*/
enum Fl_RGB_Scaling {
FL_RGB_SCALING_NEAREST = 0, ///< default RGB image scaling algorithm
FL_RGB_SCALING_BILINEAR ///< more accurate, but slower RGB image scaling algorithm
};
/**
\brief Base class for image caching and drawing.
Fl_Image is the base class used for caching and drawing all kinds of images
in FLTK. This class keeps track of common image data such as the pixels,
colormap, width, height, and depth. Virtual methods are used to provide
type-specific image handling.
Since the Fl_Image class does not support image
drawing by itself, calling the draw() method results in
a box with an X in it being drawn instead.
*/
class FL_EXPORT Fl_Image {
friend class Fl_Graphics_Driver;
public:
static const int ERR_NO_IMAGE = -1;
static const int ERR_FILE_ACCESS = -2;
static const int ERR_FORMAT = -3;
private:
int w_, h_, d_, ld_, count_;
const char * const *data_;
static Fl_RGB_Scaling RGB_scaling_;
// Forbid use of copy constructor and assign operator
Fl_Image & operator=(const Fl_Image &);
Fl_Image(const Fl_Image &);
protected:
/**
Sets the current image width in pixels.
*/
void w(int W) {w_ = W;}
/**
Sets the current image height in pixels.
*/
void h(int H) {h_ = H;}
/**
Sets the current image depth.
*/
void d(int D) {d_ = D;}
/**
Sets the current line data size in bytes.
Color images may contain extra data that is included after every
line of color image data and is normally not present.
If \p LD is zero, then line data size is assumed to be w() * d() bytes.
If \p LD is non-zero, then it must be positive and larger than w() * d()
to account for the extra data per line.
*/
void ld(int LD) {ld_ = LD;}
/**
Sets the current array pointer and count of pointers in the array.
*/
void data(const char * const *p, int c) {data_ = p; count_ = c;}
void draw_empty(int X, int Y);
static void labeltype(const Fl_Label *lo, int lx, int ly, int lw, int lh, Fl_Align la);
static void measure(const Fl_Label *lo, int &lw, int &lh);
virtual int draw_scaled(int X, int Y, int W, int H);
public:
/**
Returns the current image width in pixels.
*/
int w() const {return w_;}
/**
Returns the current image height in pixels.
*/
int h() const {return h_;}
/**
Returns the current image depth.
The return value will be 0 for bitmaps, 1 for
pixmaps, and 1 to 4 for color images.</P>
*/
int d() const {return d_;}
/**
Returns the current line data size in bytes.
\see ld(int)
*/
int ld() const {return ld_;}
/**
The count() method returns the number of data values
associated with the image. The value will be 0 for images with
no associated data, 1 for bitmap and color images, and greater
than 2 for pixmap images.
*/
int count() const {return count_;}
/**
Returns a pointer to the current image data array.
Use the count() method to find the size of the data array.
*/
const char * const *data() const {return data_;}
int fail();
Fl_Image(int W, int H, int D);
virtual ~Fl_Image();
virtual Fl_Image *copy(int W, int H);
/**
The copy() method creates a copy of the specified
image. If the width and height are provided, the image is
resized to the specified size. The image should be deleted (or in
the case of Fl_Shared_Image, released) when you are done
with it.
*/
Fl_Image *copy() { return copy(w(), h()); }
virtual void color_average(Fl_Color c, float i);
/**
The inactive() method calls
color_average(FL_BACKGROUND_COLOR, 0.33f) to produce
an image that appears grayed out.
An internal copy is made of the original image before
changes are applied, to avoid modifying the original image.
*/
void inactive() { color_average(FL_GRAY, .33f); }
virtual void desaturate();
virtual void label(Fl_Widget*w);
virtual void label(Fl_Menu_Item*m);
/**
Draws the image to the current drawing surface with a bounding box.
Arguments <tt>X,Y,W,H</tt> specify
a bounding box for the image, with the origin
(upper-left corner) of the image offset by the \c cx
and \c cy arguments.
In other words: <tt>fl_push_clip(X,Y,W,H)</tt> is applied,
the image is drawn with its upper-left corner at <tt>X-cx,Y-cy</tt> and its own width and height,
<tt>fl_pop_clip</tt><tt>()</tt> is applied.
*/
virtual void draw(int X, int Y, int W, int H, int cx=0, int cy=0); // platform dependent
/**
Draws the image to the current drawing surface.
\param X, Y specify the upper-lefthand corner of the image.
*/
void draw(int X, int Y) {draw(X, Y, w(), h(), 0, 0);} // platform dependent
virtual void uncache();
// used by fl_define_FL_IMAGE_LABEL() to avoid 'friend' declaration
static Fl_Labeltype define_FL_IMAGE_LABEL();
// set RGB image scaling method
static void RGB_scaling(Fl_RGB_Scaling);
// get RGB image scaling method
static Fl_RGB_Scaling RGB_scaling();
/** Use this method if you have an Fl_Image object and want to know whether it is derived
from class Fl_RGB_Image.
If the method returns non-NULL, then the image in question is
derived from Fl_RGB_Image, and the returned value is a pointer to this image.
*/
virtual Fl_RGB_Image *as_rgb_image() {return NULL;}
};
/**
The Fl_RGB_Image class supports caching and drawing
of full-color images with 1 to 4 channels of color information.
Images with an even number of channels are assumed to contain
alpha information, which is used to blend the image with the
contents of the screen.
Fl_RGB_Image is defined in
&lt;FL/Fl_Image.H&gt;, however for compatibility reasons
&lt;FL/Fl_RGB_Image.H&gt; should be included.
*/
class FL_EXPORT Fl_RGB_Image : public Fl_Image {
friend class Fl_Graphics_Driver;
static size_t max_size_;
public:
/** Points to the start of the object's data array
*/
const uchar *array;
/** If non-zero, the object's data array is delete[]'d when deleting the object.
*/
int alloc_array;
private:
// These two variables are used to cache the image and mask for the main display graphics driver
fl_uintptr_t id_;
fl_uintptr_t mask_;
Introduce HiDPI + rescaling support for the X11 platform (+ partial support for WIN32) Corresponds to STR #3320 1) HiDPI support consists in detecting the adequate scaling factor for the screen on which FLTK maps a window, and scaling all FLTK units by this factor. FLTK tries to detect the correct value of this factor at startup (see more details below). Environment variable FLTK_SCALING_FACTOR can also be used to set this value. 2) Rescaling support consists in changing the scaling factor of all FLTK windows in reply to ctrl/+/-/0/ keystrokes. More details for the various platforms : - X11: Support is very advanced. Some details need still to be improved. Automatic detection of the correct starting value of the scaling factor works well with the gnome desktop. The present code contains no support for this on other desktops. FLTK_SCALING_FACTOR provides a workaround. -WIN32: Support is incomplete at this point, although many test applications have partial or complete HiDPI and scaling support. The current value of the system's scaling factor is correctly detected at application startup. Apps respond to changes of this value in real time. Support needs to define the FLTK_HIDPI_SUPPORT preprocessor variable at compile time. This way, standard builds produce a code with the default WIN32 HiDPI support, that is, where all graphics goes to an internal buffer that gets enlarged by the system and then mapped to the HiDPI display. To experiment with (or develop) the new HiDPI support requires a modified build procedure in which FLTK_HIDPI_SUPPORT is defined at compile time. When the support will be complete, the requirement for the definition of this preprocessor variable will be removed. The present commit contains support for a single scaling factor. Eventually, per-screen scaling factors should be implemented, as done for X11. - MacOS: this commit does not give new HiDPI for this platform. Eventually, window rescaling in reply to command/+/-/0/ is desirable. Per-screen scaling factor makes no sense on this platform because the OS itself takes care of the difference between the resolutions of traditional and retina displays. git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12239 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
2017-05-17 14:54:18 +03:00
float cache_scale_; // graphics scaling value when id_ was computed
protected:
virtual int draw_scaled(int X, int Y, int W, int H);
public:
Fl_RGB_Image(const uchar *bits, int W, int H, int D=3, int LD=0);
Fl_RGB_Image(const Fl_Pixmap *pxm, Fl_Color bg=FL_GRAY);
virtual ~Fl_RGB_Image();
virtual Fl_Image *copy(int W, int H);
Fl_Image *copy() { return copy(w(), h()); }
virtual void color_average(Fl_Color c, float i);
virtual void desaturate();
virtual void draw(int X, int Y, int W, int H, int cx=0, int cy=0);
void draw(int X, int Y) {draw(X, Y, w(), h(), 0, 0);}
virtual void label(Fl_Widget*w);
virtual void label(Fl_Menu_Item*m);
virtual void uncache();
/** Sets the maximum allowed image size in bytes when creating an Fl_RGB_Image object.
The image size in bytes of an Fl_RGB_Image object is the value of the product w() * h() * d().
If this product exceeds size, the created object of a derived class of Fl_RGB_Image
won't be loaded with the image data.
This does not apply to direct RGB image creation with
Fl_RGB_Image::Fl_RGB_Image(const uchar *bits, int W, int H, int D, int LD).
The default max_size() value is essentially infinite.
*/
static void max_size(size_t size) { max_size_ = size;}
/** Returns the maximum allowed image size in bytes when creating an Fl_RGB_Image object.
\sa void Fl_RGB_Image::max_size(size_t)
*/
static size_t max_size() {return max_size_;}
virtual Fl_RGB_Image *as_rgb_image() {return this;}
};
#endif // !Fl_Image_H
//
// End of "$Id$".
//