fltk/documentation/Fl_Image.html
Michael R Sweet 4dc5732a3e Image class docos.
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<H2><A name="Fl_Image">class Fl_Image</A></H2>
<HR>
<H3>Class Hierarchy</H3>
<UL><PRE>
<B>Fl_Image</B>
|
+----<A href="Fl_Bitmap.html">Fl_Bitmap</A>,
<A href="Fl_Pixmap.html">Fl_Pixmap</A>,
<A href="Fl_RGB_Image.html">Fl_RGB_Image</A>,
<A href="Fl_Shared_Image.html">Fl_Shared_Image</A>,
<A href="Fl_Tiled_Image.html">Fl_Tiled_Image</A>
</PRE></UL>
<H3>Include Files</H3>
<UL><PRE>
#include &lt;FL/Fl_Image.H&gt;
</PRE></UL>
<H3>Description</H3>
<P><TT>Fl_Image</TT> 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.</P>
<P>Since the <TT>Fl_Image</TT> class does not support image
drawing by itself, calling the <TT>draw()</TT> method results in
a box with an X in it being drawn instead.</P>
<H3>Methods</H3>
<UL>
<LI><A href="#Fl_Image.Fl_Image">Fl_Image</A></LI>
<LI><A href="#Fl_Image.~Fl_Image">~Fl_Image</A></LI>
<LI><A href="#Fl_Image.color_average">color_average</A></LI>
<LI><A href="#Fl_Image.copy">copy</A></LI>
<LI><A href="#Fl_Image.count">count</A></LI>
<LI><A href="#Fl_Image.d">d</A></LI>
<LI><A href="#Fl_Image.data">data</A></LI>
<LI><A href="#Fl_Image.desaturate">desaturate</A></LI>
<LI><A href="#Fl_Image.draw">draw</A></LI>
<LI><A href="#Fl_Image.draw_empty">draw_empty</A></LI>
<LI><A href="#Fl_Image.h">h</A></LI>
<LI><A href="#Fl_Image.inactive">inactive</A></LI>
<LI><A href="#Fl_Image.label">label</A></LI>
<LI><A href="#Fl_Image.ld">ld</A></LI>
<LI><A href="#Fl_Image.w">w</A></LI>
</UL>
<H4><A NAME="Fl_Image.Fl_Image">Fl_Image(int W, int H, int D);</A></H4>
<P>The constructor creates an empty image with the specified
width, height, and depth. The width and height are in pixels.
The depth is 0 for bitmaps, 1 for pixmap (colormap) images, and
1 to 4 for color images.</P>
<H4><A NAME="Fl_Image.~Fl_Image">virtual ~Fl_Image();</A></H4>
<P>The destructor is a virtual method that frees all memory used
by the image.</P>
<H4><A NAME="Fl_Image.color_average">virtual void color_average(Fl_Color c, float i);</A></H4>
<P>The <TT>color_average()</TT> method averages the colors in
the image with the FLTK color value <TT>c</TT>. The <TT>i</TT>
argument specifies the amount of the original image to combine
with the color, so a value of 1.0 results in no color blend, and
a value of 0.0 results in a constant image of the specified
color. <I>The original image data is not altered by this
method.</I></P>
<H4><A NAME="Fl_Image.copy">virtual Fl_Image *copy(int W, int H);<BR>
copy();</A></H4>
<P>The <TT>copy()</TT> method creates a copy of the specified
image. If the width and height are provided, the image is
resized to the specified size.</P>
<H4><A NAME="Fl_Image.count">int count();</A></H4>
<P>The <TT>count()</TT> 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.</P>
<H4><A NAME="Fl_Image.d">int d();<BR>
protected void d(int D);</A></H4>
<P>The first form of the <TT>d()</TT> method returns the current
image depth. The return value will be 0 for bitmaps, 1 for
pixmaps, and 1 to 4 for color images.</P>
<P>The second form is a protected method that sets the current
image depth.</P>
<H4><A NAME="Fl_Image.data">const char * const *data();<BR>
protected void data(const char * const *data, int count);</A></H4>
<P>The first form of the <TT>data()</TT> method returns a
pointer to the current image data array. Use the
<TT>count()</TT> method to find the size of the data array.</P>
<P>The second form is a protected method that sets the current
array pointer and count of pointers in the array.</P>
<H4><A NAME="Fl_Image.desaturate">virtual void desaturate()</A></H4>
<P>The <TT>desaturate()</TT> method converts an image to
grayscale. If the image contains an alpha channel (depth = 4),
the alpha channel is preserved. <I>This method does not alter
the original image data.</I></P>
<H4><A NAME="Fl_Image.draw">void draw(int X, int Y);<BR>
virtual void draw(int X, int Y, int W, int H, int cx, int cy);</A></H4>
<P>The <TT>draw()</TT> methods draw the image. The first form
specifies the upper-lefthand corner of the image. The second
form specifies a bounding box for the image, with the origin
(upper-lefthand corner) of the image offset by the <TT>cx</TT>
and <TT>cy</TT> arguments.</P>
<H4><A NAME="Fl_Image.draw_empty">protected void draw_empty(int X, int Y);</A></H4>
<P>The protected method <TT>draw_empty()</TT> draws a box with
an X in it. It can be used to draw any image that lacks image
data.</P>
<H4><A NAME="Fl_Image.h">int h();<BR>
protected void h(int H);</A></H4>
<P>The first form of the <TT>h()</TT> method returns the current
image height in pixels.</P>
<P>The second form is a protected method that sets the current
image height.</P>
<H4><A NAME="Fl_Image.inactive">void inactive();</A></H4>
<P>The <TT>inactive()</TT> method calls
<TT>color_average(FL_GRAY, 0.33f)</TT> to produce an image that
appears grayed out. <I>This method does not alter the original
image data.</I></P>
<H4><A NAME="Fl_Image.label">virtual void label(Fl_Widget *w);
virtual void label(Fl_Menu_Item *m);</A></H4>
<P>The <TT>label()</TT> methods are an obsolete way to set the
image attribute of a widget or menu item. Use the
<TT>image()</TT> or <TT>deimage()</TT> methods of the
<TT>Fl_Widget</TT> and <TT>Fl_Menu_Item</TT> classes
instead.</P>
<H4><A NAME="Fl_Image.ld">int ld();<BR>
protected void ld(int LD);</A></H4>
<P>The first form of the <TT>ld()</TT> method returns the current
line data size in bytes. Line data is extra data that is included
after each line of color image data and is normally not present.</P>
<P>The second form is a protected method that sets the current
line data size in bytes.</P>
<H4><A NAME="Fl_Image.w">int w();<BR>
protected void w(int W);</A></H4>
<P>The first form of the <TT>w()</TT> method returns the current
image width in pixels.</P>
<P>The second form is a protected method that sets the current
image width.</P>
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