Return to mouse.c CVS log

Up to [The Machine Emulator] / tme / generic

Annotation of tme/generic/mouse.c, revision 1.1

1.1     ! root        1: /* $Id: mouse.c,v 1.1 2003/07/31 01:35:28 fredette Exp $ */
        !             2: 
        !             3: /* generic/mouse.c - generic mouse implementation support: */
        !             4: 
        !             5: /*
        !             6:  * Copyright (c) 2003 Matt Fredette
        !             7:  * All rights reserved.
        !             8:  *
        !             9:  * Redistribution and use in source and binary forms, with or without
        !            10:  * modification, are permitted provided that the following conditions
        !            11:  * are met:
        !            12:  * 1. Redistributions of source code must retain the above copyright
        !            13:  *    notice, this list of conditions and the following disclaimer.
        !            14:  * 2. Redistributions in binary form must reproduce the above copyright
        !            15:  *    notice, this list of conditions and the following disclaimer in the
        !            16:  *    documentation and/or other materials provided with the distribution.
        !            17:  * 3. All advertising materials mentioning features or use of this software
        !            18:  *    must display the following acknowledgement:
        !            19:  *      This product includes software developed by Matt Fredette.
        !            20:  * 4. The name of the author may not be used to endorse or promote products
        !            21:  *    derived from this software without specific prior written permission.
        !            22:  *
        !            23:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
        !            24:  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
        !            25:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
        !            26:  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
        !            27:  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
        !            28:  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
        !            29:  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
        !            30:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
        !            31:  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
        !            32:  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
        !            33:  * POSSIBILITY OF SUCH DAMAGE.
        !            34:  */
        !            35: 
        !            36: #include <tme/common.h>
        !            37: _TME_RCSID("$Id: mouse.c,v 1.1 2003/07/31 01:35:28 fredette Exp $");
        !            38: 
        !            39: /* includes: */
        !            40: #include <tme/generic/mouse.h>
        !            41: 
        !            42: /* macros: */
        !            43: 
        !            44: /* types: */
        !            45: 
        !            46: /* this creates a new mouse buffer: */
        !            47: struct tme_mouse_buffer *
        !            48: tme_mouse_buffer_new(unsigned int size)
        !            49: {
        !            50:   struct tme_mouse_buffer *buffer;
        !            51: 
        !            52:   /* round the buffer size up to a power of two: */
        !            53:   if (size & (size - 1)) {
        !            54:     do {
        !            55:       size &= (size - 1);
        !            56:     } while (size & (size - 1));
        !            57:     size <<= 1;
        !            58:   }
        !            59: 
        !            60:   /* allocate the buffer: */
        !            61:   buffer = tme_new0(struct tme_mouse_buffer, 1);
        !            62: 
        !            63:   /* set the buffer size: */
        !            64:   buffer->tme_mouse_buffer_size = size;
        !            65: 
        !            66:   /* set the head and tail pointers: */
        !            67:   buffer->tme_mouse_buffer_head = 0;
        !            68:   buffer->tme_mouse_buffer_tail = 0;
        !            69: 
        !            70:   /* allocate the buffer events: */
        !            71:   buffer->tme_mouse_buffer_events
        !            72:     = tme_new(struct tme_mouse_event, size);
        !            73: 
        !            74:   /* done: */
        !            75:   return (buffer);
        !            76: }
        !            77: 
        !            78: /* this destroys a mouse buffer: */
        !            79: void
        !            80: tme_mouse_buffer_destroy(struct tme_mouse_buffer *buffer)
        !            81: {
        !            82: 
        !            83:   /* free the events: */
        !            84:   tme_free(buffer->tme_mouse_buffer_events);
        !            85: 
        !            86:   /* destroy the buffer itself: */
        !            87:   tme_free(buffer);
        !            88: }
        !            89: 
        !            90: /* this copies an event into a mouse buffer: */
        !            91: int
        !            92: tme_mouse_buffer_copyin(struct tme_mouse_buffer *buffer,
        !            93:                        _tme_const struct tme_mouse_event *event)
        !            94: {
        !            95:   unsigned int buffer_head, buffer_size_mask;
        !            96: 
        !            97:   buffer_head = buffer->tme_mouse_buffer_head;
        !            98:   buffer_size_mask = buffer->tme_mouse_buffer_size - 1;
        !            99: 
        !           100:   /* if the buffer is full: */
        !           101:   if (((buffer_head + 1) & buffer_size_mask)
        !           102:       == buffer->tme_mouse_buffer_tail) {
        !           103:     return (EAGAIN);
        !           104:   }
        !           105: 
        !           106:   /* put this event into the buffer: */
        !           107:   buffer->tme_mouse_buffer_events[buffer_head]
        !           108:     = *event;
        !           109: 
        !           110:   /* advance the head: */
        !           111:   buffer->tme_mouse_buffer_head
        !           112:     = (buffer_head + 1) & buffer_size_mask;
        !           113: 
        !           114:   return (TME_OK);
        !           115: }
        !           116: 
        !           117: /* this copies an event out of a mouse buffer: */
        !           118: int
        !           119: tme_mouse_buffer_copyout(struct tme_mouse_buffer *buffer,
        !           120:                         struct tme_mouse_event *events,
        !           121:                         unsigned int count)
        !           122: {
        !           123:   unsigned int buffer_head, buffer_tail;
        !           124:   unsigned int buffer_size, buffer_size_mask;
        !           125:   unsigned int resid;
        !           126: 
        !           127:   /* get the head, tail, and size mask: */
        !           128:   buffer_head = buffer->tme_mouse_buffer_head;
        !           129:   buffer_tail = buffer->tme_mouse_buffer_tail;
        !           130:   buffer_size_mask = buffer->tme_mouse_buffer_size - 1;
        !           131: 
        !           132:   for (resid = count; resid > 0; ) {
        !           133: 
        !           134:     /* if the buffer is empty: */
        !           135:     if (buffer_tail == buffer->tme_mouse_buffer_head) {
        !           136: 
        !           137:       /* we're done copying out: */
        !           138:       break;
        !           139:     }
        !           140: 
        !           141:     /* otherwise, the buffer is not empty, meaning there is always some
        !           142:        data starting at the buffer tail.  if the buffer tail > the
        !           143:        buffer head, there is space from the buffer tail up to the end
        !           144:        of the buffer, otherwise there is space from the buffer tail up
        !           145:        to the buffer head: */
        !           146:     buffer_size = ((buffer_tail > buffer_head)
        !           147:                   ? (buffer_size_mask - buffer_tail) + 1
        !           148:                   : (buffer_head - buffer_tail));
        !           149: 
        !           150:     /* don't copy out more data than there is space available: */
        !           151:     buffer_size = TME_MIN(buffer_size, resid);
        !           152:     assert(buffer_size > 0);
        !           153: 
        !           154:     /* copy out the data: */
        !           155:     memcpy(events,
        !           156:           buffer->tme_mouse_buffer_events + buffer_tail,
        !           157:           sizeof(struct tme_mouse_event) * buffer_size);
        !           158:     events += buffer_size;
        !           159: 
        !           160:     /* update and loop: */
        !           161:     buffer_tail = (buffer_tail + buffer_size) & buffer_size_mask;
        !           162:     resid -= buffer_size;
        !           163:   }
        !           164: 
        !           165:   buffer->tme_mouse_buffer_tail = buffer_tail;
        !           166:   return (count - resid);
        !           167: }

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.