source: libcaca/trunk/caca/graphics.c @ 672

Last change on this file since 672 was 672, checked in by Sam Hocevar, 14 years ago
  • Slightly changed header comments.
  • Property svn:keywords set to Id
File size: 4.6 KB
Line 
1/*
2 *  libcaca       Colour ASCII-Art library
3 *  Copyright (c) 2002-2006 Sam Hocevar <sam@zoy.org>
4 *                All Rights Reserved
5 *
6 *  This library is free software; you can redistribute it and/or
7 *  modify it under the terms of the Do What The Fuck You Want To
8 *  Public License, Version 2, as published by Sam Hocevar. See
9 *  http://sam.zoy.org/wtfpl/COPYING for more details.
10 */
11
12/** \file graphics.c
13 *  \version \$Id: graphics.c 672 2006-03-22 21:15:57Z sam $
14 *  \author Sam Hocevar <sam@zoy.org>
15 *  \brief Character drawing
16 *
17 *  This file contains character and string drawing functions.
18 */
19
20#include "config.h"
21
22#include "caca.h"
23#include "caca_internals.h"
24#include "cucul.h"
25#include "cucul_internals.h"
26
27/** \brief Set the window title.
28 *
29 *  If libcaca runs in a window, try to change its title. This works with
30 *  the X11 and Win32 drivers.
31 *
32 *  \param title The desired window title.
33 *  \return 0 upon success, a non-zero value if an error occurs.
34 */
35int caca_set_window_title(caca_t *kk, char const *title)
36{
37    return kk->drv.set_window_title(kk, title);
38}
39
40/** \brief Get the window width.
41 *
42 *  If libcaca runs in a window, get the usable window width. This value can
43 *  be used for aspect ratio calculation. If libcaca does not run in a window
44 *  or if there is no way to know the font size, most drivers will assume a
45 *  6x10 font is being used. Note that the units are not necessarily pixels.
46 *
47 *  \return The window width.
48 */
49unsigned int caca_get_window_width(caca_t *kk)
50{
51    return kk->drv.get_window_width(kk);
52}
53
54/** \brief Get the window height.
55 *
56 *  If libcaca runs in a window, get the usable window height. This value can
57 *  be used for aspect ratio calculation. If libcaca does not run in a window
58 *  or if there is no way to know the font size, assume a 6x10 font is being
59 *  used. Note that the units are not necessarily pixels.
60 *
61 *  \return The window height.
62 */
63unsigned int caca_get_window_height(caca_t *kk)
64{
65    return kk->drv.get_window_height(kk);
66}
67
68/** \brief Set the refresh delay.
69 *
70 *  This function sets the refresh delay in microseconds. The refresh delay
71 *  is used by caca_display() to achieve constant framerate. See the
72 *  caca_display() documentation for more details.
73 *
74 *  If the argument is zero, constant framerate is disabled. This is the
75 *  default behaviour.
76 *
77 *  \param usec The refresh delay in microseconds.
78 */
79void caca_set_delay(caca_t *kk, unsigned int usec)
80{
81    kk->delay = usec;
82}
83
84/** \brief Get the average rendering time.
85 *
86 *  This function returns the average rendering time, which is the average
87 *  measured time between two caca_display() calls, in microseconds. If
88 *  constant framerate was activated by calling caca_set_delay(), the average
89 *  rendering time will not be considerably shorter than the requested delay
90 *  even if the real rendering time was shorter.
91 *
92 *  \return The render time in microseconds.
93 */
94unsigned int caca_get_rendertime(caca_t *kk)
95{
96    return kk->rendertime;
97}
98
99/** \brief Flush pending changes and redraw the screen.
100 *
101 *  This function flushes all graphical operations and prints them to the
102 *  screen. Nothing will show on the screen until caca_display() is
103 *  called.
104 *
105 *  If caca_set_delay() was called with a non-zero value, caca_display()
106 *  will use that value to achieve constant framerate: if two consecutive
107 *  calls to caca_display() are within a time range shorter than the value
108 *  set with caca_set_delay(), the second call will wait a bit before
109 *  performing the screen refresh.
110 */
111void caca_display(caca_t *kk)
112{
113#if !defined(_DOXYGEN_SKIP_ME)
114#define IDLE_USEC 10000
115#endif
116    int ticks = kk->lastticks + _caca_getticks(&kk->timer);
117
118    kk->drv.display(kk);
119
120    /* Once the display is finished, we can ack resizes */
121    if(kk->resize.resized)
122    {
123        kk->resize.resized = 0;
124        _caca_handle_resize(kk);
125    }
126
127    /* Wait until kk->delay + time of last call */
128    ticks += _caca_getticks(&kk->timer);
129    for(ticks += _caca_getticks(&kk->timer);
130        ticks + IDLE_USEC < (int)kk->delay;
131        ticks += _caca_getticks(&kk->timer))
132    {
133        _caca_sleep(IDLE_USEC);
134    }
135
136    /* Update the sliding mean of the render time */
137    kk->rendertime = (7 * kk->rendertime + ticks) / 8;
138
139    kk->lastticks = ticks - kk->delay;
140
141    /* If we drifted too much, it's bad, bad, bad. */
142    if(kk->lastticks > (int)kk->delay)
143        kk->lastticks = 0;
144}
145
146/*
147 * XXX: following functions are local
148 */
149
150void _caca_handle_resize(caca_t *kk)
151{
152    kk->drv.handle_resize(kk);
153
154    /* Tell libcucul we changed size */
155    if(kk->resize.w != kk->qq->width || kk->resize.h != kk->qq->height)
156        _cucul_set_size(kk->qq, kk->resize.w, kk->resize.h);
157}
158
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