a36b1d4083
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8349 a1c6a512-1295-4272-9138-f99709370657
258 lines
6.8 KiB
C
258 lines
6.8 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Plasma demo plugin
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*
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* My crack at making a 80's style retro plasma effect for the fantastic
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* rockbox!
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* Okay, I could've hard-coded the sine wave values, I just wanted the
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* challange of calculating them! silly: maybe, fun: yes!
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*
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* All files in this archive are subject to the GNU General Public License.
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* See the file COPYING in the source tree root for full license agreement.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#ifndef SIMULATOR /* not for simulator by now */
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#include "plugin.h"
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#ifdef HAVE_LCD_BITMAP /* and also not for the Player */
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#include "gray.h"
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PLUGIN_HEADER
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/******************************* Globals ***********************************/
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static struct plugin_api* rb; /* global api struct pointer */
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static unsigned char *gbuf;
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static unsigned int gbuf_size = 0;
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static unsigned char wave_array[256]; /* Pre calculated wave array */
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static unsigned char colours[256]; /* Smooth transition of shades */
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static unsigned char graybuffer[LCD_HEIGHT*LCD_WIDTH]; /* off screen buffer */
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static unsigned char sp1, sp2, sp3, sp4; /* Speed of plasma */
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static int plasma_frequency;
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/* Key assignement, all bitmapped models */
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#define PLASMA_QUIT BUTTON_OFF
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#define PLASMA_INCREASE_FREQUENCY BUTTON_UP
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#define PLASMA_DECREASE_FREQUENCY BUTTON_DOWN
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#define WAV_AMP 90
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/* Precalculated sine * 16384 (fixed point 18.14) */
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static const short sin_table[91] =
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{
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0, 285, 571, 857, 1142, 1427, 1712, 1996, 2280, 2563,
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2845, 3126, 3406, 3685, 3963, 4240, 4516, 4790, 5062, 5334,
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5603, 5871, 6137, 6401, 6663, 6924, 7182, 7438, 7691, 7943,
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8191, 8438, 8682, 8923, 9161, 9397, 9630, 9860, 10086, 10310,
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10531, 10748, 10963, 11173, 11381, 11585, 11785, 11982, 12175, 12365,
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12550, 12732, 12910, 13084, 13254, 13420, 13582, 13740, 13894, 14043,
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14188, 14329, 14466, 14598, 14725, 14848, 14967, 15081, 15190, 15295,
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15395, 15491, 15582, 15668, 15749, 15825, 15897, 15964, 16025, 16082,
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16135, 16182, 16224, 16261, 16294, 16321, 16344, 16361, 16374, 16381,
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16384
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};
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static short sin(int val)
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{
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/* value should be between 0 and 360 degree for correct lookup*/
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val%=360;
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if(val<0)
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val+=360;
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/* Speed improvement through successive lookup */
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if (val < 181)
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{
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if (val < 91)
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{
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/* phase 0-90 degree */
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return (short)sin_table[val];
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}
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else
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{
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/* phase 91-180 degree */
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return (short)sin_table[180-val];
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}
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}
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else
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{
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if (val < 271)
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{
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/* phase 181-270 degree */
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return -(short)sin_table[val-180];
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}
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else
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{
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/* phase 270-359 degree */
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return -(short)sin_table[360-val];
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}
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}
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return 0;
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}
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/*
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* Main wave function so we don't have to re-calc the sine
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* curve every time. Mess around WAV_AMP and FREQ to make slighlty
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* weirder looking plasmas!
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*/
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static void wave_table_generate(void)
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{
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int i;
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for (i=0;i<256;++i)
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{
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wave_array[i] = (unsigned char)((WAV_AMP
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* (sin((i * 360 * plasma_frequency) / 256))) / 16384);
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}
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}
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/*
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* This function is to make a smooth shade from white into
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* black and back into white again. I thought this would be quicker
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* than calculating on the fly - am I wrong?
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*/
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static void shades_generate(void)
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{
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int i=1;
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int j=0;
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int nAdd=2;
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for(i=0; i < 256; ++i)
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{
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colours[i] = j;
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j += nAdd;
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if(j > 240 || j < 2)
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{
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nAdd = -nAdd;
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}
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}
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}
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void cleanup(void *parameter)
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{
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(void)parameter;
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gray_release();
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rb->backlight_set_timeout(rb->global_settings->backlight_timeout);
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}
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/*
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* Main function that also contain the main plasma
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* algorithm.
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*/
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int main(void)
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{
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plasma_frequency = 1;
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int shades, button, x, y;
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unsigned char p1,p2,p3,p4,t1,t2,t3,t4, z;
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int n=0;
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/*Generate the neccesary pre calced stuff*/
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wave_table_generate();
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shades_generate();
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/* get the remainder of the plugin buffer */
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gbuf = (unsigned char *) rb->plugin_get_buffer(&gbuf_size);
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shades = gray_init(rb, gbuf, gbuf_size, false, LCD_WIDTH, LCD_HEIGHT/8,
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32, NULL) + 1;
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/* switch on grayscale overlay */
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gray_show(true);
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sp1 = 4;
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sp2 = 2;
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sp3 = 4;
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sp4 = 2;
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p1=p2=p3=p4=0;
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while (true)
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{
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t1=p1;
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t2=p2;
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n=0;
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for(y = 0; y < LCD_HEIGHT; ++y)
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{
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t3=p3;
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t4=p4;
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for(x = 0; x < LCD_WIDTH; ++x)
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{
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z = wave_array[t1] + wave_array[t2] + wave_array[t3]
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+ wave_array[t4];
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graybuffer[n] = colours[z];
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t3+=1;
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t4+=2;
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++n;
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}
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t1+=2;
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t2+=1;
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rb->yield();
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}
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p1+=sp1;
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p2-=sp2;
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p3+=sp3;
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p4-=sp4;
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gray_ub_gray_bitmap(graybuffer, 0, 0, LCD_WIDTH, LCD_HEIGHT);
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button = rb->button_get(false);
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switch(button)
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{
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case(PLASMA_QUIT):
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cleanup(NULL);
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return PLUGIN_OK;
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break;
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case (PLASMA_INCREASE_FREQUENCY):
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++plasma_frequency;
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wave_table_generate();
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break;
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case (PLASMA_DECREASE_FREQUENCY):
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if(plasma_frequency>1)
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{
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--plasma_frequency;
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wave_table_generate();
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}
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break;
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default:
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if (rb->default_event_handler_ex(button, cleanup, NULL)
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== SYS_USB_CONNECTED)
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return PLUGIN_USB_CONNECTED;
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break;
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}
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}
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}
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/*************************** Plugin entry point ****************************/
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enum plugin_status plugin_start(struct plugin_api* api, void* parameter)
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{
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int ret;
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rb = api; // copy to global api pointer
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(void)parameter;
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if (rb->global_settings->backlight_timeout > 0)
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rb->backlight_set_timeout(1);/* keep the light on */
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ret = main();
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return ret;
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}
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#endif // #ifdef HAVE_LCD_BITMAP
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#endif // #ifndef SIMULATOR
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