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| author | Michael R Sweet <michael.r.sweet@gmail.com> | 1999-01-13 19:28:54 +0000 |
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| committer | Michael R Sweet <michael.r.sweet@gmail.com> | 1999-01-13 19:28:54 +0000 |
| commit | d7b88a3bcc7e76f38ee5799be7722fd5a10781ef (patch) | |
| tree | d8984d45424c9b2cdb199c1918f38bfea4a8211d /documentation/drawing.html | |
| parent | 30fa233681467b82b165e7d42cd0bea778b93768 (diff) | |
Updated all links so they work between files.
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diff --git a/documentation/drawing.html b/documentation/drawing.html index 9219273eb..df1e395fb 100644 --- a/documentation/drawing.html +++ b/documentation/drawing.html @@ -1,681 +1,507 @@ -<HTML> -<BODY> - +<HTML><BODY> <H1><A NAME=drawing>5 - Drawing Things in FLTK</A></H1> - -This chapter covers the drawing functions that are provided with FLTK. - -<h2>When Can You Draw Things in FLTK?</h2> - -There are only certain places you can execute drawing code in FLTK. -Calling these functions at other places will result in undefined -behavior! - -<ul> - - <li>The most common is inside the virtual method <a - href="#draw"><tt>Fl_Widget::draw()</tt></a>. To write code - here, you must subclass one of the existing <tt>Fl_Widget</tt> - classes and implement your own version of <tt>draw()</tt>. - - <li>You can also write <a href="#boxtypes">boxtypes</a> and <a - href="#labeltypes">labeltypes</a>. These are small procedures - that can be called by existing <tt>Fl_Widget</tt> - <tt>draw()</tt> methods. These "types" are identified by an - 8-bit index that is stored in the widget's <tt>box()</tt>, - <tt>labeltype()</tt>, and possibly other properties. - - <li>You can call <a - href="#Fl_Window.make_current"><tt>Fl_Window::make_current()</tt></a> - to do incremental update of a widget. Use <a - href="#Fl_Widget.window"><tt>Fl_Widget::window()</tt></a> to - find the window. <i>Under X this only works for the base - <tt>Fl_Window</tt> class, not for double buffered, overlay, or - OpenGL windows!</i> - -</ul> - -<h2>FLTK Drawing Functions</h2> - -To use the drawing functions you must first include the -<tt><FL/fl_draw.H></tt> header file. FLTK provides the following types -of drawing functions: - -<ul> - <li><a href="#clipping">Clipping</a> - <li><a href="#color">Colors</a> - <li><a href="#fast">Fast Shapes</a> - <li><a href="#vertex">Complex Shapes</a> - <li><a href="#text">Text</a> - <li><a href="#images">Images</a> - <li><a href="#cursor">Cursor</a> - <li><a href="#overlay">Overlay</a> -</ul> - -<h3><a name="clipping">Clipping</a></h3> - -You can limit all your drawing to a rectangular region by calling -<tt>fl_clip</tt>, and put the drawings back by using -<tt>fl_pop_clip</tt>. This rectangle is measured in pixels (it is -unaffected by the current transformation matrix). - -<p>In addition, the system may provide clipping when updating windows, -this clip region may be more complex than a simple rectangle. - -<h4>void fl_clip(int x, int y, int w, int h)</h4> - -Intersect the current clip region with a rectangle and push this new -region onto the stack. - -<h4>void fl_pop_clip()</h4> - -Restore the previous clip region. <i>You must call -<tt>fl_pop_clip()</tt> once for every time you call -<tt>fl_clip()</tt>. If you return to FLTK with the clip stack not -empty unpredictable results occur.</i> - -<h4>int fl_not_clipped(int x, int y, int w, int h)</h4> - -Returns true if any of the rectangle intersects the current clip -region. If this returns false you don't have to draw the object. -<i>Under X this returns 2 if the rectangle is partially clipped, and 1 -if it is entirely inside the clip region</i>. - -<h4>int fl_clip_box(int x, int y, int w, int h, int &X, int &Y, int &W, int &H)</h4> - -Intersect the rectangle <tt>x,y,w,h</tt> with the current clip region -and returns the bounding box of the result in <tt>X,Y,W,H</tt>. -Returns non-zero if the resulting rectangle is different than the -original. This can be used to limit the necessary drawing to a -rectangle. <tt>W</tt> and <tt>H</tt> are set to zero if the rectangle -is completely outside the region. - -<h3><a name="colors">Colors</a></h3> - -<h4>void fl_color(Fl_Color)</h4> - -Set the color for all subsequent drawing operations. <tt>Fl_Color</tt> -is an enumeration type, and all values are in the range 0-255. This is -<i>not</i> the X or WIN32 pixel, it is an index into an internal -table! The table provides several general colors, a 24-entry gray -ramp, and a 5x8x5 color cube. All of these are named with -poorly-documented symbols in <a -href=#enumerations><tt><FL/Enumerations.H></tt></a>. - -<p>For colormapped displays, a color cell will be allocated out of -<tt>fl_colormap</tt> the first time you use a color. If the colormap -fills up then a least-squares algorithm is used to find the closest -color. - -<h4>Fl_Color fl_color()</h4> - -Returns the last <tt>fl_color()</tt> that was set. This can be used for state -save/restore. - -<h4>void fl_color(uchar r, uchar g, uchar b)</h4> - -Set the color for all subsequent drawing operations. The closest -possible match to the RGB color is used. The RGB color is used -directly on TrueColor displays. For colormap visuals the nearest index -in the gray ramp or color cube is used. - -<h3><a name="fast_shapes">Fast Shapes</a></h3> - -These are used to draw almost all the FLTK widgets. They draw on exact -pixel boundaries and are as fast as possible, and their behavior will -be duplicated exactly on any platform FLTK is ported to. It is -undefined whether these are affected by the <a -href="#complex_shapes">transformation matrix</a>, so you should only call these -while it is the identity. - -<h4>void fl_rectf(int x, int y, int w, int h)</h4> - -Color a rectangle that exactly fills the given bounding box. - -<h4>void fl_rectf(int x, int y, int w, int h, uchar r, uchar g, uchar b)</h4> - -Color a rectangle with "exactly" the passed <tt>r,g,b</tt> color. On -screens with less than 24 bits of color this is done by drawing a -solid-colored block using <a -href="#fl_draw_image"><tt>fl_draw_image()</tt></a> so that dithering is -produced. - -<h4>void fl_rect(int x, int y, int w, int h)</h4> - -Draw a 1-pixel border <i>inside</i> this bounding box. - -<h4>void fl_line(int x, int y, int x1, int y1)<br> -void fl_line(int x, int y, int x1, int y1, int x2, int y2)</h4> - -Draw one or two 1-pixel thick lines between the given points. - -<h4>void fl_loop(int x, int y, int x1, int y1, int x2, int y2)<br> -void fl_loop(int x, int y, int x1, int y1, int x2, int y2, int x3, int y3)</h4> - -Outline a 3 or 4-sided polygon with 1-pixel thick lines. - -<h4>void fl_polygon(int x, int y, int x1, int y1, int x2, int y2)<br> -void fl_polygon(int x, int y, int x1, int y1, int x2, int y2, int x3, int y3)</h4> - -Fill a 3 or 4-sided polygon. The polygon must be convex. - -<h4>void fl_xyline(int x, int y, int x1, int y1)<br> -void fl_xyline(int x, int y, int x1, int y1, int x2)<br> -void fl_xyline(int x, int y, int x1, int y1, int x2, int y3)</h4> - -Draw 1-pixel wide horizontal and vertical lines. A horizontal line is -drawn first, then a vertical, then a horizontal. - -<h4>void fl_yxline(int x, int y, int y1)<br> -void fl_yxline(int x, int y, int y1, int x2)<br> -void fl_yxline(int x, int y, int y1, int x2, int y3)</h4> - -Draw 1-pixel wide vertical and horizontal lines. A vertical line is -drawn first, then a horizontal, then a vertical. - -<h4>void fl_arc(int x, int y, int w, int h, double a1, double a2)<br> -void fl_pie(int x, int y, int w, int h, double a1, double a2)<br> -void fl_chord(int x, int y, int w, int h, double a1, double a2)</h4> - -High-speed ellipse sections. These functions match the rather limited -circle drawing code provided by X and MSWindows. The advantage over -using <a href="#fl_arc"><tt>fl_arc</tt></a> is that they are faster -because they often use the hardware, and they draw much nicer small -circles, since the small sizes are often hard-coded bitmaps. - -<p>If a complete circle is drawn it will fit inside the passed -bounding box. The two angles are measured in degrees counterclockwise -from 3'oclock and are the starting and ending angle of the arc, <tt>a2</tt> -must be greater or equal to <tt>a1</tt>. - -<p><tt>fl_arc()</tt> draws a 1-pixel thick line (notice this has a different -number of arguments than the <a href="#fl_arc"><tt>fl_arc()</tt></a> described -below. - -<p><tt>fl_pie()</tt> draws a filled-in pie slice. This slice may extend outside -the line drawn by <tt>fl_arc</tt>, to avoid this use <tt>w - 1</tt> and -<tt>h - 1</tt>. - -<p><tt>fl_chord()</tt> is not yet implemented. - -<h3><a name="complex_shapes">Complex Shapes</a></h3> - -These functions let you draw arbitrary shapes with 2-D linear -transformations. The functionality matches that found in Adobe® -PostScript<sup>TM</sup>. The exact pixels filled in is less defined -than for the above calls, so that FLTK can take advantage of drawing -hardware. The transformed vertices are rounded to integers before -drawing the line segments. This severely limits the accuracy of these -functions for complex graphics. Use OpenGL when greater accuracy -and/or performance is required. - -<h4>void fl_push_matrix()<br> -void fl_pop_matrix()</h4> - -Save and restore the current transformation. The maximum depth of the -stack is 4. - -<h4>void fl_scale(float x, float y)<br> -void fl_scale(float x)<br> -void fl_translate(float x, float y)<br> -void fl_rotate(float d)<br> -void fl_mult_matrix(float a, float b, float c, float d, float x, float y)</h4> - -Concatenate another transformation onto the current one. The rotation angle -is in degrees (not radians) and is counter-clockwise. - -<h4>void fl_begin_line()<br> -void fl_end_line()</h4> - -Start and end drawing 1-pixel thick lines. - -<h4>void fl_begin_loop()<br> -void fl_end_loop()</h4> - -Start and end drawing a closed sequence of 1-pixel thick lines. - -<h4>void fl_begin_polygon()<br> -void fl_end_polygon()</h4> - -Start and end drawing a convex filled polygon. - -<h4>void fl_begin_complex_polygon()<br> -void fl_gap()<br> -void fl_end_complex_polygon()</h4> - -Start and end drawing a complex filled polygon. This polygon may be -concave, may have holes in it, or may be several disconnected pieces. -Call <tt>fl_gap()</tt> to seperate loops of the path (it is unnecessary -but harmless to call <tt>fl_gap()</tt> before the first vertex, after -the last one, or several times in a row). For portability, you should -only draw polygons that appear the same whether "even/odd" or -"non-zero" winding rules are used to fill them. This mostly means that -holes should be drawn in the opposite direction of the outside. - -<p><tt>fl_gap()</tt> should only be called between -<tt>fl_begin_complex_polygon()</tt> and -<tt>fl_end_complex_polygon()</tt>. To outline the polygon, use -<tt>fl_begin_loop()</tt> and replace each <tt>fl_gap()</tt> with -<tt>fl_end_loop();fl_begin_loop()<tt>. - -<h4>void fl_vertex(float x, float y)</h4> - -Add a single vertex to the current path. - -<h4>void fl_curve(float x, float y, float x1, float y1, float x2, float y2, float x3, float y3)</h4> - -Add a series of points on a Bezier curve to the path. The curve ends -(and two of the points) are at <tt>x,y</tt> and <tt>x3,y3</tt>. - -<h4>void fl_arc(float x, float y, float r, float start, float end)</h4> - -Add a series of points to the current path on the arc of a circle (you -can get elliptical paths by using scale and rotate before calling -this). <tt>x,y</tt> are the center of the circle, and <tt>r</tt> is -its radius. <tt>fl_arc()</tt> takes <tt>start</tt> and <tt>end</tt> -angles that are measured in degrees counter-clockwise from 3 o'clock. -If <tt>end</tt> is less than <tt>start</tt> then it draws the arc in a -clockwise direction. - -<h4>void fl_circle(float x, float y, float r)</h4> - -<tt>fl_circle()</tt> is equivalent to <tt>fl_arc(...,0,360)</tt> but -may be faster. It must be the <i>only</i> thing in the path: if you -want a circle as part of a complex polygon you must use -<tt>fl_arc()</tt>. <i>This draws incorrectly if the transformation is -both rotated and non-square scaled.</i> - -<h3><a name="text">Text</a></h3> - -All text is drawn in the <a href="#fl_font">current font</a>. It is -undefined whether this location or the characters are modified by the -current transformation. - -<h4>void fl_draw(const char *, float x, float y)<br> -void fl_draw(const char *, int n, float x, float y)</h4> - -Draw a nul-terminated string or an array of <tt>n</tt> characters -starting at the given location. - -<h4>void fl_draw(const char *, int x, int y, int w, int h, Fl_Align)</h4> - -Fancy string drawing function which is used to draw all the labels. -The string is formatted and aligned inside the passed box. Handles -'\t' and '\n', expands all other control characters to ^X, and aligns -inside or against the edges of the box. See <a -href="#Fl_Widget.align"><tt>Fl_Widget::align()</tt></a> for values for -<tt>align</tt>. The value <tt>FL_ALIGN_INSIDE</tt> is ignored, as this -function always prints inside the box. - -<h4>void fl_measure(const char *, int &w, int &h)</h4> - -Measure how wide and tall the string will be when printed by the -<tt>fl_draw(...align)</tt> function. If the incoming <tt>w</tt> is -non-zero it will wrap to that width. - -<h4>int fl_height()</h4> - -Recommended minimum line spacing for the current font. You can also -just use the value of <tt>size</tt> passed to <a href="#fl_font"> -<tt>fl_font()</tt></a>. - -<h4>int fl_descent()</h4> - -Recommended distance above the bottom of a <tt>fl_height()</tt> tall -box to draw the text at so it looks centered vertically in that box. - -<h4>float fl_width(const char*)<br> -float fl_width(const char*, int n)<br> -float fl_width(uchar)</h4> - -Return the width of a nul-terminated string, a sequence of <tt>n</tt> -characters, or a single character. - -<h4>const char *fl_shortcut_label(ulong)</h4> - -Unparse a shortcut value as used by <a -href="#Fl_Button.shortcut"><tt>Fl_Button</tt></a> or <a -href="#Fl_Menu_Item"><tt>Fl_Menu_Item</tt></a> into a human-readable -string like "Alt+N". This only works if the shortcut is a character -key or a numbered function key. If the shortcut is zero an empty -string is returned. The return value points at a static buffer that is -overwritten with each call. - -<h3><a name="fonts">Fonts</a></h3> - -<h4><a name="fl_font">void fl_font(int face, int size)</a></h4> - -Set the current font, which is then used by the routines described -above. You may call this outside a draw context if necessary to call -<tt>fl_width()</tt>, but on X this will open the display. - -<p>The font is identified by a <tt>face</tt> and a <tt>size</tt>. The -size of the font is measured in <tt>pixels</tt> (i.e. it is not -"resolution [in]dependent"). Lines should be spaced <tt>size</tt> -pixels apart (or more). - -<p>The <tt>face</tt> is an index into an internal table. Initially -only the first 16 faces are filled in. There are symbolic names for -them: <tt>FL_HELVETICA</tt>, <tt>FL_TIMES</tt>, <tt>FL_COURIER</tt>, -and modifier values <tt>FL_BOLD</tt> and <tt>FL_ITALIC</tt> which can -be added to these, and <tt>FL_SYMBOL</tt> and -<tt>FL_ZAPF_DINGBATS</tt>. Faces greater than 255 cannot be used in -<tt>Fl_Widget</tt> labels, since it stores the index as a byte. - -<h4>int fl_font()<br> -int fl_size()</h4> - -Returns the face and size set by the most recent call to -<tt>fl_font(a,b)</tt>. This can be used to save/restore the font. - -<h3><a name="cursor">Cursor</a></h3> - -<h4>void fl_cursor(Fl_Cursor, Fl_Color = FL_WHITE, Fl_Color = FL_BLACK)</h4> - -Change the cursor. Depending on the system this may affect the cursor -everywhere, or only when it is pointing at the window that is current -when you call this. For portability you should change the cursor back -to the default in response to <tt>FL_LEAVE</tt> events. - -<p>The type <tt>Fl_Cursor</tt> is an enumeration defined in <a -href="#enumerations"><tt><Enumerations.H></tt></a>. The -double-headed arrows are bitmaps provided by FLTK on X, the others are -provided by system-defined cursors. Under X you can get any XC_cursor -value by passing <tt>Fl_Cursor((XC_foo/2)+1)</tt>. - -<p>The following standard cursors are available: - -<ul> - <li><tt>FL_CURSOR_DEFAULT</tt> - the default cursor, usually an arrow - <li><tt>FL_CURSOR_ARROW</tt> - an arrow pointer - <li><tt>FL_CURSOR_CROSS</tt> - crosshair - <li><tt>FL_CURSOR_WAIT</tt> - watch or hourglass - <li><tt>FL_CURSOR_INSERT</tt> - I-beam - <li><tt>FL_CURSOR_HAND</tt> - hand (uparrow on MSWindows) - <li><tt>FL_CURSOR_HELP</tt> - question mark - <li><tt>FL_CURSOR_MOVE</tt> - 4-pointed arrow - <li><tt>FL_CURSOR_NS</tt> - up/down arrow - <li><tt>FL_CURSOR_WE</tt> - left/right arrow - <li><tt>FL_CURSOR_NWSE</tt> - diagonal arrow - <li><tt>FL_CURSOR_NESW</tt> - diagonal arrow - <li><tt>FL_CURSOR_NONE</tt> - invisible -</ul> - -<h3><a name="overlay">Overlays</a></h3> - -<h4>void fl_overlay_rect(int x, int y, int w, int h)<br> -void fl_overlay_clear()</h4> - -These functions allow you to draw interactive selection rectangles -without using the overlay hardware. FLTK will XOR a single rectangle -outline over a window. Calling this will erase any previous rectangle -(by XOR'ing it), and then draw the new one. Calling -<tt>fl_overlay_clear()</tt> will erase the rectangle without drawing a -new one. - -<p>Using this is tricky. You should make a widget with both a -<tt>handle()</tt> and <tt>draw()</tt> method. <tt>draw()</tt> should -call <tt>fl_overlay_clear()</tt> before doing anything else. Your -<tt>handle()</tt> method should call <tt>window()->make_current()</tt> -and then <tt>fl_overlay_rect()</tt> after <tt>FL_DRAG</tt> events, and -should call <tt>fl_overlay_clear()</tt> after a <tt>FL_RELEASE</tt> -event. - -<h2><a name="images">Images</a></h2> - -To draw images, you can either do it directly from data in your memory, -or you can create <a href="#Fl_Bitmap"><tt>Fl_Bitmap</tt></a>, <a -href="#Fl_Image"><tt>Fl_Image</tt></a>, or <a -href="#Fl_Pixmap"><tt>Fl_Pixmap</tt></a> objects. The advantage of -drawing directly is that it is more intuitive, and it is faster if the -image data changes more often than it is redrawn. The advantage of -using the object is that FLTK will cache translated forms of the image -(on X it uses a server pixmap) and thus redrawing is <i>much</i> -faster. - -<h3>Direct Image Drawing</h3> - -It is undefined whether the location or drawing of the image is -affected by the current transformation, so you should only call these -when it is the identity. - -<h4>void fl_draw_bitmap(const uchar *, int X, int Y, int W, int H, int LD = 0)</h4> - -This function is planned but not yet implemented (it may be impossible -under X without allocating a pixmap). - -<h4>void fl_draw_image(const uchar *, int X, int Y, int W, int H, int D = 3, int LD = 0)<br> -void fl_draw_image_mono(const uchar *, int X, int Y, int W, int H, int D = 1, int LD = 0)</h4> - -Draw an 8-bit per color RGB or luminance image. The pointer points at -the "r" data of the top-left pixel. Data must be in <tt>r,g,b</tt> -order. <tt>X,Y</tt> are where to put the top-left corner. <tt>W</tt> -and <tt>H</tt> define the size of the image. <tt>D</tt> is the delta -to add to the pointer between pixels, it may be any value greater or -equal to <tt>3</tt>, or it can be negative to flip the image -horizontally. <tt>LD</tt> is the delta to add to the pointer between -lines (if 0 is passed it uses <tt>W * D</tt>), and may be larger than -<tt>W * D</tt> to crop data, or negative to flip the image vertically. - -<p>It is highly recommended that you put the following code before the -first <tt>show()</tt> of <i>any</i> window in your program to get rid -of the dithering if possible: - -<ul><pre> + This chapter covers the drawing functions that are provided with FLTK. +<H2>When Can You Draw Things in FLTK?</H2> + There are only certain places you can execute drawing code in FLTK. +Calling these functions at other places will result in undefined +behavior! +<UL> +<LI>The most common is inside the virtual method <A href=#draw><TT> +Fl_Widget::draw()</TT></A>. To write code here, you must subclass one +of the existing <TT>Fl_Widget</TT> classes and implement your own +version of <TT>draw()</TT>. </LI> +<LI>You can also write <A href=common.html#boxtypes>boxtypes</A> and <A href=#labeltypes> +labeltypes</A>. These are small procedures that can be called by +existing <TT>Fl_Widget</TT><TT>draw()</TT> methods. These "types" are +identified by an 8-bit index that is stored in the widget's <TT>box()</TT> +, <TT>labeltype()</TT>, and possibly other properties. </LI> +<LI>You can call <A href=Fl_Window.html#Fl_Window.make_current><TT> +Fl_Window::make_current()</TT></A> to do incremental update of a +widget. Use <A href=Fl_Widget.html#Fl_Widget.window><TT> +Fl_Widget::window()</TT></A> to find the window. <I>Under X this only +works for the base <TT>Fl_Window</TT> class, not for double buffered, +overlay, or OpenGL windows!</I></LI> +</UL> +<H2>FLTK Drawing Functions</H2> + To use the drawing functions you must first include the <TT> +<FL/fl_draw.H></TT> header file. FLTK provides the following types of +drawing functions: +<UL> +<LI><A href=#clipping>Clipping</A></LI> +<LI><A href=#color>Colors</A></LI> +<LI><A href=#fast>Fast Shapes</A></LI> +<LI><A href=#vertex>Complex Shapes</A></LI> +<LI><A href=#text>Text</A></LI> +<LI><A href=#images>Images</A></LI> +<LI><A href=#cursor>Cursor</A></LI> +<LI><A href=#overlay>Overlay</A></LI> +</UL> +<H3><A name=clipping>Clipping</A></H3> + You can limit all your drawing to a rectangular region by calling <TT> +fl_clip</TT>, and put the drawings back by using <TT>fl_pop_clip</TT>. + This rectangle is measured in pixels (it is unaffected by the current +transformation matrix). +<P>In addition, the system may provide clipping when updating windows, +this clip region may be more complex than a simple rectangle. </P> +<H4>void fl_clip(int x, int y, int w, int h)</H4> + Intersect the current clip region with a rectangle and push this new +region onto the stack. +<H4>void fl_pop_clip()</H4> + Restore the previous clip region. <I>You must call <TT>fl_pop_clip()</TT> + once for every time you call <TT>fl_clip()</TT>. If you return to +FLTK with the clip stack not empty unpredictable results occur.</I> +<H4>int fl_not_clipped(int x, int y, int w, int h)</H4> + Returns true if any of the rectangle intersects the current clip +region. If this returns false you don't have to draw the object. <I> +Under X this returns 2 if the rectangle is partially clipped, and 1 if +it is entirely inside the clip region</I>. +<H4>int fl_clip_box(int x, int y, int w, int h, int &X, int &Y, int &W, +int &H)</H4> + Intersect the rectangle <TT>x,y,w,h</TT> with the current clip region +and returns the bounding box of the result in <TT>X,Y,W,H</TT>. + Returns non-zero if the resulting rectangle is different than the +original. This can be used to limit the necessary drawing to a +rectangle. <TT>W</TT> and <TT>H</TT> are set to zero if the rectangle +is completely outside the region. +<H3><A name=colors>Colors</A></H3> +<H4>void fl_color(Fl_Color)</H4> + Set the color for all subsequent drawing operations. <TT>Fl_Color</TT> + is an enumeration type, and all values are in the range 0-255. This +is <I>not</I> the X or WIN32 pixel, it is an index into an internal +table! The table provides several general colors, a 24-entry gray +ramp, and a 5x8x5 color cube. All of these are named with +poorly-documented symbols in <A href=enumerations.html#enumerations><TT> +<FL/Enumerations.H></TT></A>. +<P>For colormapped displays, a color cell will be allocated out of <TT> +fl_colormap</TT> the first time you use a color. If the colormap fills +up then a least-squares algorithm is used to find the closest color. </P> +<H4>Fl_Color fl_color()</H4> + Returns the last <TT>fl_color()</TT> that was set. This can be used +for state save/restore. +<H4>void fl_color(uchar r, uchar g, uchar b)</H4> + Set the color for all subsequent drawing operations. The closest +possible match to the RGB color is used. The RGB color is used +directly on TrueColor displays. For colormap visuals the nearest index +in the gray ramp or color cube is used. +<H3><A name=fast_shapes>Fast Shapes</A></H3> + These are used to draw almost all the FLTK widgets. They draw on +exact pixel boundaries and are as fast as possible, and their behavior +will be duplicated exactly on any platform FLTK is ported to. It is +undefined whether these are affected by the <A href=#complex_shapes> +transformation matrix</A>, so you should only call these while it is +the identity. +<H4>void fl_rectf(int x, int y, int w, int h)</H4> + Color a rectangle that exactly fills the given bounding box. +<H4>void fl_rectf(int x, int y, int w, int h, uchar r, uchar g, uchar b)</H4> + Color a rectangle with "exactly" the passed <TT>r,g,b</TT> color. On +screens with less than 24 bits of color this is done by drawing a +solid-colored block using <A href=#fl_draw_image><TT>fl_draw_image()</TT> +</A> so that dithering is produced. +<H4>void fl_rect(int x, int y, int w, int h)</H4> + Draw a 1-pixel border <I>inside</I> this bounding box. +<H4>void fl_line(int x, int y, int x1, int y1) +<BR> void fl_line(int x, int y, int x1, int y1, int x2, int y2)</H4> + Draw one or two 1-pixel thick lines between the given points. +<H4>void fl_loop(int x, int y, int x1, int y1, int x2, int y2) +<BR> void fl_loop(int x, int y, int x1, int y1, int x2, int y2, int x3, +int y3)</H4> + Outline a 3 or 4-sided polygon with 1-pixel thick lines. +<H4>void fl_polygon(int x, int y, int x1, int y1, int x2, int y2) +<BR> void fl_polygon(int x, int y, int x1, int y1, int x2, int y2, int +x3, int y3)</H4> + Fill a 3 or 4-sided polygon. The polygon must be convex. +<H4>void fl_xyline(int x, int y, int x1, int y1) +<BR> void fl_xyline(int x, int y, int x1, int y1, int x2) +<BR> void fl_xyline(int x, int y, int x1, int y1, int x2, int y3)</H4> + Draw 1-pixel wide horizontal and vertical lines. A horizontal line is +drawn first, then a vertical, then a horizontal. +<H4>void fl_yxline(int x, int y, int y1) +<BR> void fl_yxline(int x, int y, int y1, int x2) +<BR> void fl_yxline(int x, int y, int y1, int x2, int y3)</H4> + Draw 1-pixel wide vertical and horizontal lines. A vertical line is +drawn first, then a horizontal, then a vertical. +<H4>void fl_arc(int x, int y, int w, int h, double a1, double a2) +<BR> void fl_pie(int x, int y, int w, int h, double a1, double a2) +<BR> void fl_chord(int x, int y, int w, int h, double a1, double a2)</H4> + High-speed ellipse sections. These functions match the rather limited +circle drawing code provided by X and MSWindows. The advantage over +using <A href=#fl_arc><TT>fl_arc</TT></A> is that they are faster +because they often use the hardware, and they draw much nicer small +circles, since the small sizes are often hard-coded bitmaps. +<P>If a complete circle is drawn it will fit inside the passed bounding +box. The two angles are measured in degrees counterclockwise from +3'oclock and are the starting and ending angle of the arc, <TT>a2</TT> + must be greater or equal to <TT>a1</TT>. </P> +<P><TT>fl_arc()</TT> draws a 1-pixel thick line (notice this has a +different number of arguments than the <A href=#fl_arc><TT>fl_arc()</TT></A> + described below. </P> +<P><TT>fl_pie()</TT> draws a filled-in pie slice. This slice may +extend outside the line drawn by <TT>fl_arc</TT>, to avoid this use <TT> +w - 1</TT> and <TT>h - 1</TT>. </P> +<P><TT>fl_chord()</TT> is not yet implemented. </P> +<H3><A name=complex_shapes>Complex Shapes</A></H3> + These functions let you draw arbitrary shapes with 2-D linear +transformations. The functionality matches that found in Adobe® +PostScript<SUP>TM</SUP>. The exact pixels filled in is less defined +than for the above calls, so that FLTK can take advantage of drawing +hardware. The transformed vertices are rounded to integers before +drawing the line segments. This severely limits the accuracy of these +functions for complex graphics. Use OpenGL when greater accuracy +and/or performance is required. +<H4>void fl_push_matrix() +<BR> void fl_pop_matrix()</H4> + Save and restore the current transformation. The maximum depth of the +stack is 4. +<H4>void fl_scale(float x, float y) +<BR> void fl_scale(float x) +<BR> void fl_translate(float x, float y) +<BR> void fl_rotate(float d) +<BR> void fl_mult_matrix(float a, float b, float c, float d, float +x, float y)</H4> + Concatenate another transformation onto the current one. The rotation +angle is in degrees (not radians) and is counter-clockwise. +<H4>void fl_begin_line() +<BR> void fl_end_line()</H4> + Start and end drawing 1-pixel thick lines. +<H4>void fl_begin_loop() +<BR> void fl_end_loop()</H4> + Start and end drawing a closed sequence of 1-pixel thick lines. +<H4>void fl_begin_polygon() +<BR> void fl_end_polygon()</H4> + Start and end drawing a convex filled polygon. +<H4>void fl_begin_complex_polygon() +<BR> void fl_gap() +<BR> void fl_end_complex_polygon()</H4> + Start and end drawing a complex filled polygon. This polygon may be +concave, may have holes in it, or may be several disconnected pieces. +Call <TT>fl_gap()</TT> to seperate loops of the path (it is unnecessary +but harmless to call <TT>fl_gap()</TT> before the first vertex, after +the last one, or several times in a row). For portability, you should +only draw polygons that appear the same whether "even/odd" or +"non-zero" winding rules are used to fill them. This mostly means that +holes should be drawn in the opposite direction of the outside. +<P><TT>fl_gap()</TT> should only be called between <TT> +fl_begin_complex_polygon()</TT> and <TT>fl_end_complex_polygon()</TT>. + To outline the polygon, use <TT>fl_begin_loop()</TT> and replace each <TT> +fl_gap()</TT> with <TT>fl_end_loop();fl_begin_loop()<TT>. </TT></TT></P> +<H4>void fl_vertex(float x, float y)</H4> + Add a single vertex to the current path. +<H4>void fl_curve(float x, float y, float x1, float y1, float x2, float +y2, float x3, float y3)</H4> + Add a series of points on a Bezier curve to the path. The curve ends +(and two of the points) are at <TT>x,y</TT> and <TT>x3,y3</TT>. +<H4>void fl_arc(float x, float y, float r, float start, float end)</H4> + Add a series of points to the current path on the arc of a circle (you +can get elliptical paths by using scale and rotate before calling +this). <TT>x,y</TT> are the center of the circle, and <TT>r</TT> is its +radius. <TT>fl_arc()</TT> takes <TT>start</TT> and <TT>end</TT> angles +that are measured in degrees counter-clockwise from 3 o'clock. If <TT> +end</TT> is less than <TT>start</TT> then it draws the arc in a +clockwise direction. +<H4>void fl_circle(float x, float y, float r)</H4> +<TT>fl_circle()</TT> is equivalent to <TT>fl_arc(...,0,360)</TT> but +may be faster. It must be the <I>only</I> thing in the path: if you +want a circle as part of a complex polygon you must use <TT>fl_arc()</TT> +. <I>This draws incorrectly if the transformation is both rotated and +non-square scaled.</I> +<H3><A name=text>Text</A></H3> + All text is drawn in the <A href=#fl_font>current font</A>. It is +undefined whether this location or the characters are modified by the +current transformation. +<H4>void fl_draw(const char *, float x, float y) +<BR> void fl_draw(const char *, int n, float x, float y)</H4> + Draw a nul-terminated string or an array of <TT>n</TT> characters +starting at the given location. +<H4>void fl_draw(const char *, int x, int y, int w, int h, Fl_Align)</H4> + Fancy string drawing function which is used to draw all the labels. +The string is formatted and aligned inside the passed box. Handles +'\t' and '\n', expands all other control characters to ^X, and aligns +inside or against the edges of the box. See <A href=Fl_Widget.html#Fl_Widget.align> +<TT>Fl_Widget::align()</TT></A> for values for <TT>align</TT>. The +value <TT>FL_ALIGN_INSIDE</TT> is ignored, as this function always +prints inside the box. +<H4>void fl_measure(const char *, int &w, int &h)</H4> + Measure how wide and tall the string will be when printed by the <TT> +fl_draw(...align)</TT> function. If the incoming <TT>w</TT> is +non-zero it will wrap to that width. +<H4>int fl_height()</H4> + Recommended minimum line spacing for the current font. You can also +just use the value of <TT>size</TT> passed to <A href=#fl_font><TT> +fl_font()</TT></A>. +<H4>int fl_descent()</H4> + Recommended distance above the bottom of a <TT>fl_height()</TT> tall +box to draw the text at so it looks centered vertically in that box. +<H4>float fl_width(const char*) +<BR> float fl_width(const char*, int n) +<BR> float fl_width(uchar)</H4> + Return the width of a nul-terminated string, a sequence of <TT>n</TT> + characters, or a single character. +<H4>const char *fl_shortcut_label(ulong)</H4> + Unparse a shortcut value as used by <A href=Fl_Button.html#Fl_Button.shortcut> +<TT>Fl_Button</TT></A> or <A href=Fl_Menu_Item.html#Fl_Menu_Item><TT> +Fl_Menu_Item</TT></A> into a human-readable string like "Alt+N". This +only works if the shortcut is a character key or a numbered function +key. If the shortcut is zero an empty string is returned. The return +value points at a static buffer that is overwritten with each call. +<H3><A name=fonts>Fonts</A></H3> +<H4><A name=fl_font>void fl_font(int face, int size)</A></H4> + Set the current font, which is then used by the routines described +above. You may call this outside a draw context if necessary to call <TT> +fl_width()</TT>, but on X this will open the display. +<P>The font is identified by a <TT>face</TT> and a <TT>size</TT>. The +size of the font is measured in <TT>pixels</TT> (i.e. it is not +"resolution [in]dependent"). Lines should be spaced <TT>size</TT> + pixels apart (or more). </P> +<P>The <TT>face</TT> is an index into an internal table. Initially +only the first 16 faces are filled in. There are symbolic names for +them: <TT>FL_HELVETICA</TT>, <TT>FL_TIMES</TT>, <TT>FL_COURIER</TT>, +and modifier values <TT>FL_BOLD</TT> and <TT>FL_ITALIC</TT> which can +be added to these, and <TT>FL_SYMBOL</TT> and <TT>FL_ZAPF_DINGBATS</TT> +. Faces greater than 255 cannot be used in <TT>Fl_Widget</TT> labels, +since it stores the index as a byte. </P> +<H4>int fl_font() +<BR> int fl_size()</H4> + Returns the face and size set by the most recent call to <TT> +fl_font(a,b)</TT>. This can be used to save/restore the font. +<H3><A name=cursor>Cursor</A></H3> +<H4>void fl_cursor(Fl_Cursor, Fl_Color = FL_WHITE, Fl_Color = FL_BLACK)</H4> + Change the cursor. Depending on the system this may affect the cursor +everywhere, or only when it is pointing at the window that is current +when you call this. For portability you should change the cursor back +to the default in response to <TT>FL_LEAVE</TT> events. +<P>The type <TT>Fl_Cursor</TT> is an enumeration defined in <A href=enumerations.html#enumerations> +<TT><Enumerations.H></TT></A>. The double-headed arrows are bitmaps +provided by FLTK on X, the others are provided by system-defined +cursors. Under X you can get any XC_cursor value by passing <TT> +Fl_Cursor((XC_foo/2)+1)</TT>. </P> +<P>The following standard cursors are available: </P> +<UL> +<LI><TT>FL_CURSOR_DEFAULT</TT> - the default cursor, usually an arrow </LI> +<LI><TT>FL_CURSOR_ARROW</TT> - an arrow pointer </LI> +<LI><TT>FL_CURSOR_CROSS</TT> - crosshair </LI> +<LI><TT>FL_CURSOR_WAIT</TT> - watch or hourglass </LI> +<LI><TT>FL_CURSOR_INSERT</TT> - I-beam </LI> +<LI><TT>FL_CURSOR_HAND</TT> - hand (uparrow on MSWindows) </LI> +<LI><TT>FL_CURSOR_HELP</TT> - question mark </LI> +<LI><TT>FL_CURSOR_MOVE</TT> - 4-pointed arrow </LI> +<LI><TT>FL_CURSOR_NS</TT> - up/down arrow </LI> +<LI><TT>FL_CURSOR_WE</TT> - left/right arrow </LI> +<LI><TT>FL_CURSOR_NWSE</TT> - diagonal arrow </LI> +<LI><TT>FL_CURSOR_NESW</TT> - diagonal arrow </LI> +<LI><TT>FL_CURSOR_NONE</TT> - invisible </LI> +</UL> +<H3><A name=overlay>Overlays</A></H3> +<H4>void fl_overlay_rect(int x, int y, int w, int h) +<BR> void fl_overlay_clear()</H4> + These functions allow you to draw interactive selection rectangles +without using the overlay hardware. FLTK will XOR a single rectangle +outline over a window. Calling this will erase any previous rectangle +(by XOR'ing it), and then draw the new one. Calling <TT> +fl_overlay_clear()</TT> will erase the rectangle without drawing a new +one. +<P>Using this is tricky. You should make a widget with both a <TT> +handle()</TT> and <TT>draw()</TT> method. <TT>draw()</TT> should call <TT> +fl_overlay_clear()</TT> before doing anything else. Your <TT>handle()</TT> + method should call <TT>window()->make_current()</TT> and then <TT> +fl_overlay_rect()</TT> after <TT>FL_DRAG</TT> events, and should call <TT> +fl_overlay_clear()</TT> after a <TT>FL_RELEASE</TT> event. </P> +<H2><A name=images>Images</A></H2> + To draw images, you can either do it directly from data in your +memory, or you can create <A href=#Fl_Bitmap><TT>Fl_Bitmap</TT></A>, <A href=#Fl_Image> +<TT>Fl_Image</TT></A>, or <A href=#Fl_Pixmap><TT>Fl_Pixmap</TT></A> + objects. The advantage of drawing directly is that it is more +intuitive, and it is faster if the image data changes more often than +it is redrawn. The advantage of using the object is that FLTK will +cache translated forms of the image (on X it uses a server pixmap) and +thus redrawing is <I>much</I> faster. +<H3>Direct Image Drawing</H3> + It is undefined whether the location or drawing of the image is +affected by the current transformation, so you should only call these +when it is the identity. +<H4>void fl_draw_bitmap(const uchar *, int X, int Y, int W, int H, int +LD = 0)</H4> + This function is planned but not yet implemented (it may be impossible +under X without allocating a pixmap). +<H4>void fl_draw_image(const uchar *, int X, int Y, int W, int H, int D += 3, int LD = 0) +<BR> void fl_draw_image_mono(const uchar *, int X, int Y, int W, int H, +int D = 1, int LD = 0)</H4> + Draw an 8-bit per color RGB or luminance image. The pointer points at +the "r" data of the top-left pixel. Data must be in <TT>r,g,b</TT> + order. <TT>X,Y</TT> are where to put the top-left corner. <TT>W</TT> + and <TT>H</TT> define the size of the image. <TT>D</TT> is the delta +to add to the pointer between pixels, it may be any value greater or +equal to <TT>3</TT>, or it can be negative to flip the image +horizontally. <TT>LD</TT> is the delta to add to the pointer between +lines (if 0 is passed it uses <TT>W * D</TT>), and may be larger than <TT> +W * D</TT> to crop data, or negative to flip the image vertically. +<P>It is highly recommended that you put the following code before the +first <TT>show()</TT> of <I>any</I> window in your program to get rid +of the dithering if possible: </P> +<UL> +<PRE> Fl::visual(FL_RGB); -</pre></ul> - -Gray scale (1-channel) images may be drawn. This is done if -<tt>abs(D)</tt> is less than 3, or by calling -<tt>fl_draw_image_mono()</tt>. Only one 8-bit sample is used for each -pixel, and on screens with different numbers of bits for red, green, -and blue only gray colors are used. Setting <tt>D</tt> greater than 1 -will let you display one channel of a color image. - -<p><i>The X version does not support all possible visuals.</i> If FLTK -cannot draw the image in the current visual it will abort. FLTK -supports any visual of 8 bits or less, and all common TrueColor -visuals up to 32 bits. - -<h4>typedef void (*fl_draw_image_cb)(void *, int x, int y, int w, uchar *)<br> -void fl_draw_image(fl_draw_image_cb, void *, int X, int Y, int W, int H, int D = 3)<br> -void fl_draw_image_mono(fl_draw_image_cb, void *, int X, int Y, int W, int H, int D = 1)</h4> - -Call the passed function to provide each scan line of the image. This -lets you generate the image as it is being drawn, or do arbitrary -decompression of stored data (provided it can be decompressed to -individual scan lines easily). - -<p>The callback is called with the <tt>void *</tt> user data pointer -(this can be used to point at a structure of information about the -image), and the <tt>x</tt>, <tt>y</tt>, and <tt>w</tt> of the scan line -desired from the image. 0,0 is the upper-left corner (<i>not -<tt>X,Y</tt></i>). A pointer to a buffer to put the data into is -passed. You must copy <tt>w</tt> pixels from scanline <tt>y</tt>, -starting at pixel <tt>x</tt>, to this buffer. - -<p>Due to cropping, less than the whole image may be requested. So -<tt>x</tt> may be greater than zero, the first <tt>y</tt> may be -greater than zero, and <tt>w</tt> may be less than <tt>W</tt>. The -buffer is long enough to store the entire <tt>W * D</tt> pixels, this -is for convienence with some decompression schemes where you must -decompress the entire line at once: decompress it into the buffer, and -then if <tt>x</tt> is not zero, copy the data over so the <tt>x</tt>'th -pixel is at the start of the buffer. - -<p>You can assume the <tt>y</tt>'s will be consecutive, except the first one -may be greater than zero. - -<p>If <tt>D</tt> is 4 or more, you must fill in the unused bytes with zero. - -<h4>int fl_draw_pixmap(char **data, int X, int Y, Fl_Color = FL_GRAY)</h4> - -Draw XPM image data, with the top-left corner at the given position. -The images is dithered on 8-bit displays so you won't lose color space -for programs displaying both images and pixmaps. This function -returns zero if there was any error decoding the XPM data. - -<p>To use an XPM, do: - -<ul><pre> -#include "foo.xpm" +</PRE> +</UL> + Gray scale (1-channel) images may be drawn. This is done if <TT>abs(D)</TT> + is less than 3, or by calling <TT>fl_draw_image_mono()</TT>. Only one +8-bit sample is used for each pixel, and on screens with different +numbers of bits for red, green, and blue only gray colors are used. + Setting <TT>D</TT> greater than 1 will let you display one channel of +a color image. +<P><I>The X version does not support all possible visuals.</I> If FLTK +cannot draw the image in the current visual it will abort. FLTK +supports any visual of 8 bits or less, and all common TrueColor visuals +up to 32 bits. </P> +<H4>typedef void (*fl_draw_image_cb)(void *, int x, int y, int w, uchar +*) +<BR> void fl_draw_image(fl_draw_image_cb, void *, int X, int Y, int W, +int H, int D = 3) +<BR> void fl_draw_image_mono(fl_draw_image_cb, void *, int X, int Y, +int W, int H, int D = 1)</H4> + Call the passed function to provide each scan line of the image. This +lets you generate the image as it is being drawn, or do arbitrary +decompression of stored data (provided it can be decompressed to +individual scan lines easily). +<P>The callback is called with the <TT>void *</TT> user data pointer +(this can be used to point at a structure of information about the +image), and the <TT>x</TT>, <TT>y</TT>, and <TT>w</TT> of the scan line +desired from the image. 0,0 is the upper-left corner (<I>not <TT>X,Y</TT> +</I>). A pointer to a buffer to put the data into is passed. You must +copy <TT>w</TT> pixels from scanline <TT>y</TT>, starting at pixel <TT>x</TT> +, to this buffer. </P> +<P>Due to cropping, less than the whole image may be requested. So <TT> +x</TT> may be greater than zero, the first <TT>y</TT> may be greater +than zero, and <TT>w</TT> may be less than <TT>W</TT>. The buffer is +long enough to store the entire <TT>W * D</TT> pixels, this is for +convienence with some decompression schemes where you must decompress +the entire line at once: decompress it into the buffer, and then if <TT> +x</TT> is not zero, copy the data over so the <TT>x</TT>'th pixel is at +the start of the buffer. </P> +<P>You can assume the <TT>y</TT>'s will be consecutive, except the +first one may be greater than zero. </P> +<P>If <TT>D</TT> is 4 or more, you must fill in the unused bytes with +zero. </P> +<H4>int fl_draw_pixmap(char **data, int X, int Y, Fl_Color = FL_GRAY)</H4> + Draw XPM image data, with the top-left corner at the given position. +The images is dithered on 8-bit displays so you won't lose color space +for programs displaying both images and pixmaps. This function returns +zero if there was any error decoding the XPM data. +<P>To use an XPM, do: </P> +<UL> +<PRE> +#include "foo.xpm" ... fl_draw_pixmap(foo, X, Y); -</pre></ul> - -In the current version the XPM data is converted to 8-bit full color -and passed through <tt>fl_draw_image()</tt>. This is obviously not the -most efficient way to do it, and has the same visual limitations as -listed above for <tt>fl_draw_image()</tt>. Transparent colors are -replaced by the optional <tt>Fl_Color</tt> argument (this may change in -the future). - -<h4>int fl_measure_pixmap(char **data, int &w, int &h)</h4> - -An XPM image contains the dimensions in its data. This function -finds and returns the width and height. The return value is non-zero -if it parsed the dimensions ok, and zero if there is any problem. - -<h3><a name="Fl_Bitmap">class Fl_Bitmap</a></h3> - -This object encapsulates the width, height, and bits of an X bitmap -(XBM), and allows you to make an <tt>Fl_Widget</tt> use a bitmap as a -label, or to just draw the bitmap directly. Under X it will create an -offscreen pixmap the first time it is drawn, and copy this each -subsequent time it is drawn. - -<h4>Fl_Bitmap(const char *bits, int W, int H)<br> -Fl_Bitmap(const uchar *bits, int W, int H)</h4> - -Construct using an X bitmap. The bits pointer is simply copied to the -object, so it must point at persistent storage. The two constructors -are provided because various X implementations disagree about the type -of bitmap data. To use an XBM file use: - -<ul><pre> -#include "foo.xbm" +</PRE> +</UL> + In the current version the XPM data is converted to 8-bit full color +and passed through <TT>fl_draw_image()</TT>. This is obviously not the +most efficient way to do it, and has the same visual limitations as +listed above for <TT>fl_draw_image()</TT>. Transparent colors are +replaced by the optional <TT>Fl_Color</TT> argument (this may change in +the future). +<H4>int fl_measure_pixmap(char **data, int &w, int &h)</H4> + An XPM image contains the dimensions in its data. This function finds +and returns the width and height. The return value is non-zero if it +parsed the dimensions ok, and zero if there is any problem. +<H3><A name=Fl_Bitmap>class Fl_Bitmap</A></H3> + This object encapsulates the width, height, and bits of an X bitmap +(XBM), and allows you to make an <TT>Fl_Widget</TT> use a bitmap as a +label, or to just draw the bitmap directly. Under X it will create an +offscreen pixmap the first time it is drawn, and copy this each +subsequent time it is drawn. +<H4>Fl_Bitmap(const char *bits, int W, int H) +<BR> Fl_Bitmap(const uchar *bits, int W, int H)</H4> + Construct using an X bitmap. The bits pointer is simply copied to the +object, so it must point at persistent storage. The two constructors +are provided because various X implementations disagree about the type +of bitmap data. To use an XBM file use: +<UL> +<PRE> +#include "foo.xbm" ... Fl_Bitmap bitmap = new Fl_Bitmap(foo_bits, foo_width, foo_height); -</pre></ul> - -<h4>~Fl_Bitmap()</h4> - -The destructor will destroy any X pixmap created. It does not do -anything to the bits data. - -<h4>void draw(int x, int y, int w, int h, int ox = 0, int oy = 0)</h4> - -<tt>x,y,w,h</tt> indicates a destination rectangle. <tt>ox,oy,w,h</tt> -is a source rectangle. This source rectangle from the bitmap is drawn -in the destination. 1 bits are drawn with the current color, 0 bits -are unchanged. The source rectangle may extend outside the bitmap -(i.e. <tt>ox</tt> and <tt>oy</tt> may be negative and <tt>w</tt> and -<tt>h</tt> may be bigger than the bitmap) and this area is left -unchanged. - -<h4>void draw(int x, int y)</h4> - -Draws the bitmap with the upper-left corner at <tt>x,y</tt>. This is -the same as doing <tt>draw(x,y,this->w,this->h,0,0)</tt>. - -<h4>void label(Fl_Widget *)</h4> - -Change the <tt>label()</tt> and the <tt>labeltype()</tt> of the widget -to draw the bitmap. 1 bits will be drawn with the -<tt>labelcolor()</tt>, zero bits will be unchanged. You can use the -same bitmap for many widgets. - - -<h2><a name="Fl_Pixmap">class Fl_Pixmap</h2> - -This object encapsulates the data from an XPM image, and allows you to -make an <tt>Fl_Widget</tt> use a pixmap as a label, or to just draw the -pixmap directly. <i>Under X it will create an offscreen pixmap the -first time it is drawn, and copy this each subsequent time it is -drawn</i>. - -<p>The current implementation converts the pixmap to 8 bit color data -and uses <a href="#fl_draw_image"><tt>fl_draw_image()</tt></a> to draw -it. Thus you will get dithered colors on an 8 bit screen. - -<h4>Fl_Pixmap(char *const* data)</h4> - -Construct using XPM data. The data pointer is simply copied to the -object, so it must point at persistent storage. To use an XPM file do: - -<ul><pre> -#include <FL/Fl_Pixmap.H> -#include "foo.xpm" +</PRE> +</UL> +<H4>~Fl_Bitmap()</H4> + The destructor will destroy any X pixmap created. It does not do +anything to the bits data. +<H4>void draw(int x, int y, int w, int h, int ox = 0, int oy = 0)</H4> +<TT>x,y,w,h</TT> indicates a destination rectangle. <TT>ox,oy,w,h</TT> + is a source rectangle. This source rectangle from the bitmap is drawn +in the destination. 1 bits are drawn with the current color, 0 bits +are unchanged. The source rectangle may extend outside the bitmap +(i.e. <TT>ox</TT> and <TT>oy</TT> may be negative and <TT>w</TT> and <TT> +h</TT> may be bigger than the bitmap) and this area is left unchanged. +<H4>void draw(int x, int y)</H4> + Draws the bitmap with the upper-left corner at <TT>x,y</TT>. This is +the same as doing <TT>draw(x,y,this->w,this->h,0,0)</TT>. +<H4>void label(Fl_Widget *)</H4> + Change the <TT>label()</TT> and the <TT>labeltype()</TT> of the widget +to draw the bitmap. 1 bits will be drawn with the <TT>labelcolor()</TT> +, zero bits will be unchanged. You can use the same bitmap for many +widgets. +<H2><A name=Fl_Pixmap>class Fl_Pixmap</A></H2> + This object encapsulates the data from an XPM image, and allows you to +make an <TT>Fl_Widget</TT> use a pixmap as a label, or to just draw the +pixmap directly. <I>Under X it will create an offscreen pixmap the +first time it is drawn, and copy this each subsequent time it is drawn</I> +. +<P>The current implementation converts the pixmap to 8 bit color data +and uses <A href=#fl_draw_image><TT>fl_draw_image()</TT></A> to draw +it. Thus you will get dithered colors on an 8 bit screen. </P> +<H4>Fl_Pixmap(char *const* data)</H4> + Construct using XPM data. The data pointer is simply copied to the +object, so it must point at persistent storage. To use an XPM file do: +<UL> +<PRE> +#include <FL/Fl_Pixmap.H> +#include "foo.xpm" ... Fl_Pixmap pixmap = new Fl_Pixmap(foo); -</ul></pre> - -<h4>~Fl_Pixmap()</h4> - -The destructor will destroy any X pixmap created. It does not do -anything to the data. - -<h4>void draw(int x, int y, int w, int h, int ox = 0, int oy = 0)</h4> - -<tt>x,y,w,h</tt> indicates a destination rectangle. <tt>ox,oy,w,h</tt> -is a source rectangle. This source rectangle is copied to the -destination. The source rectangle may extend outside the pixmap (i.e. -<tt>ox</tt> and <tt>oy</tt> may be negative and <tt>w</tt> and -<tt>h</tt> may be bigger than the pixmap) and this area is left -unchanged. - -<h4>void draw(int x, int y)</h4> - -Draws the image with the upper-left corner at <tt>x,y</tt>. This is -the same as doing <tt>draw(x,y,this->w,this->h,0,0)</tt>. - -<h4>void label(Fl_Widget *)</h4> - -Change the <tt>label()</tt> and the <tt>labeltype()</tt> of the widget -to draw the pixmap. You can use the same pixmap for many widgets. - - -<H3><a name="Fl_Image">class Fl_Image</a></H3> - -This object encapsulates a full-color RGB image, and allows you to make -an <tt>Fl_Widget</tt> use an image as a label, or to just draw the -image directly. <i>Under X it will create an offscreen pixmap the -first time it is drawn, and copy this each subsequent time it is -drawn</i>. - -<h4>Fl_Image(char uchar *data, int W, int H, int D = 3, int LD = 0)</h4> - -Construct using a pointer to RGB data. <tt>W</tt> and <tt>H</tt> are -the size of the image in pixels. <tt>D</tt> is the delta between -pixels (it may be more than 3 to skip alpha or other data, or negative -to flip the image left/right). <tt>LD</tt> is the delta between lines -(it may be more than <tt>D * W</tt> to crop images, or negative to flip -the image vertically). The data pointer is simply copied to the -object, so it must point at persistent storage. - -<h4>~Fl_Image()</h4> - -The destructor will destroy any X pixmap created. It does not do -anything to the data. - -<h4>void draw(int x, int y, int w, int h, int ox = 0, int oy = 0)</h4> - -<tt>x,y,w,h</tt> indicates a destination rectangle. <tt>ox,oy,w,h</tt> -is a source rectangle. This source rectangle is copied to the -destination. The source rectangle may extend outside the image (i.e. -<tt>ox</tt> and <tt>oy</tt> may be negative and <tt>w</tt> and -<tt>h</tt> may be bigger than the image) and this area is left -unchanged. - -<h4>void draw(int x, int y)</h4> - -Draws the image with the upper-left corner at <tt>x,y</tt>. This is -the same as doing <tt>draw(x,y,this->w,this->h,0,0)</tt>. - -<h4>void label(Fl_Widget *)</h4> - -Change the <tt>label()</tt> and the <tt>labeltype()</tt> of the widget -to draw the image. You can use the same image for many widgets. - -</BODY> -</HTML> +</PRE> +</UL> +<H4>~Fl_Pixmap()</H4> + The destructor will destroy any X pixmap created. It does not do +anything to the data. +<H4>void draw(int x, int y, int w, int h, int ox = 0, int oy = 0)</H4> +<TT>x,y,w,h</TT> indicates a destination rectangle. <TT>ox,oy,w,h</TT> + is a source rectangle. This source rectangle is copied to the +destination. The source rectangle may extend outside the pixmap (i.e. <TT> +ox</TT> and <TT>oy</TT> may be negative and <TT>w</TT> and <TT>h</TT> + may be bigger than the pixmap) and this area is left unchanged. +<H4>void draw(int x, int y)</H4> + Draws the image with the upper-left corner at <TT>x,y</TT>. This is +the same as doing <TT>draw(x,y,this->w,this->h,0,0)</TT>. +<H4>void label(Fl_Widget *)</H4> + Change the <TT>label()</TT> and the <TT>labeltype()</TT> of the widget +to draw the pixmap. You can use the same pixmap for many widgets. +<H3><A name=Fl_Image>class Fl_Image</A></H3> + This object encapsulates a full-color RGB image, and allows you to +make an <TT>Fl_Widget</TT> use an image as a label, or to just draw the +image directly. <I>Under X it will create an offscreen pixmap the first +time it is drawn, and copy this each subsequent time it is drawn</I>. +<H4>Fl_Image(char uchar *data, int W, int H, int D = 3, int LD = 0)</H4> + Construct using a pointer to RGB data. <TT>W</TT> and <TT>H</TT> are +the size of the image in pixels. <TT>D</TT> is the delta between pixels +(it may be more than 3 to skip alpha or other data, or negative to flip +the image left/right). <TT>LD</TT> is the delta between lines (it may +be more than <TT>D * W</TT> to crop images, or negative to flip the +image vertically). The data pointer is simply copied to the object, so +it must point at persistent storage. +<H4>~Fl_Image()</H4> + The destructor will destroy any X pixmap created. It does not do +anything to the data. +<H4>void draw(int x, int y, int w, int h, int ox = 0, int oy = 0)</H4> +<TT>x,y,w,h</TT> indicates a destination rectangle. <TT>ox,oy,w,h</TT> + is a source rectangle. This source rectangle is copied to the +destination. The source rectangle may extend outside the image (i.e. <TT> +ox</TT> and <TT>oy</TT> may be negative and <TT>w</TT> and <TT>h</TT> + may be bigger than the image) and this area is left unchanged. +<H4>void draw(int x, int y)</H4> + Draws the image with the upper-left corner at <TT>x,y</TT>. This is +the same as doing <TT>draw(x,y,this->w,this->h,0,0)</TT>. +<H4>void label(Fl_Widget *)</H4> + Change the <TT>label()</TT> and the <TT>labeltype()</TT> of the widget +to draw the image. You can use the same image for many widgets. </BODY></HTML>
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