demos/c_simple/sin_AA.c

   1 /*****************************************************************************
   2  * This file is part of gfxprim library.                                     *
   3  *                                                                           *
   4  * Gfxprim is free software; you can redistribute it and/or                  *
   5  * modify it under the terms of the GNU Lesser General Public                *
   6  * License as published by the Free Software Foundation; either              *
   7  * version 2.1 of the License, or (at your option) any later version.        *
   8  *                                                                           *
   9  * Gfxprim is distributed in the hope that it will be useful,                *
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of            *
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU         *
  12  * Lesser General Public License for more details.                           *
  13  *                                                                           *
  14  * You should have received a copy of the GNU Lesser General Public          *
  15  * License along with gfxprim; if not, write to the Free Software            *
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor,                        *
  17  * Boston, MA  02110-1301  USA                                               *
  18  *                                                                           *
  19  * Copyright (C) 2009-2013 Cyril Hrubis <metan@ucw.cz>                       *
  20  *                                                                           *
  21  *****************************************************************************/
  22
  23 /*
  24
  25   Simple example that shows HLineAA() usage.
  26
  27  */
  28
  29 #include <stdio.h>
  30 #include <errno.h>
  31 #include <string.h>
  32
  33 #include <GP.h>
  34
  35 static void redraw(GP_Context *context)
  36 {
  37         static float param = 1;
  38         static float param2 = 0.01;
  39         static int flag = 1;
  40         GP_Pixel b = GP_RGBToContextPixel(0xbe, 0xbe, 0x9e, context);
  41         unsigned int y;
  42
  43         GP_Fill(context, b);
  44
  45         for (y = 0; y < context->w; y++) {
  46                 GP_Coord x0, x1, l1, l2;
  47
  48                 x0 = (context->w)<<7;
  49                 x1 = (context->w)<<7;
  50
  51                 l1 = (context->w)<<5;
  52                 l2 = (context->w)<<3;
  53
  54                 GP_Pixel p = GP_RGBToContextPixel(120 - 3 * param, abs(40 * param), 0, context);
  55
  56                 l2 *= 4.00 * y / context->h;
  57
  58                 l1 *= param;
  59
  60                 x0 += l1 * sin(param2 * y) + l2;
  61                 x1 -= l1 * cos(param2 * y) + l2;
  62
  63                 GP_HLineAA(context, x0, x1, y<<8, p);
  64         }
  65
  66         if (flag) {
  67                 param -= 0.02;
  68
  69                 if (param <= -2.40) {
  70                         flag = 0;
  71                         param2 += 0.01;
  72
  73                         if (param2 > 0.02)
  74                                 param2 = 0.01;
  75                 }
  76         } else {
  77                 param += 0.02;
  78
  79                 if (param >= 2.40)
  80                         flag = 1;
  81         }
  82 }
  83
  84 int main(void)
  85 {
  86         GP_Backend *backend;
  87         static int pause_flag = 0;
  88
  89         /* Initalize backend */
  90         backend = GP_BackendX11Init(NULL, 0, 0, 800, 600, "sin AA", 0);
  91
  92         if (backend == NULL) {
  93                 fprintf(stderr, "Failed to initalize backend\n");
  94                 return 1;
  95         }
  96
  97         /* Wait for events */
  98         for (;;) {
  99                 if (!pause_flag) {
 100                         redraw(backend->context);
 101                         GP_BackendFlip(backend);
 102                 }
 103
 104                 GP_BackendPoll(backend);
 105
 106                 GP_Event ev;
 107
 108                 while (GP_BackendGetEvent(backend, &ev)) {
 109                         if (ev.type == GP_EV_KEY && ev.code == GP_EV_KEY_DOWN) {
 110                                 switch (ev.val.val) {
 111                                 case GP_KEY_ESC:
 112                                 case GP_KEY_Q:
 113                                         GP_BackendExit(backend);
 114                                         return 0;
 115                                 case GP_KEY_P:
 116                                         pause_flag = !pause_flag;
 117                                 break;
 118                                 }
 119                         }
 120                 }
 121
 122                 usleep(10000);
 123         }
 124
 125         return 0;
 126 }