git.defcon.no Git - avrfbosd/blob - fbosd.c

   1 #include <avr/io.h>
   2 #include <avr/interrupt.h>
   3 #include <util/delay.h>
   4 #include <stdlib.h>
   5
   6 #include "video_properties.h"
   7 #include "render.h"
   8 #include "draw.h"
   9
  10 void (*line_handler)( void );
  11
  12 const int vres_scale = ( SCREEN_LINES / VRES -1 );
  13 const int hres_bytes = HRES / 8;
  14
  15 volatile uint8_t* screen_buffer;
  16
  17 volatile int line;
  18 volatile int buffer_position;
  19
  20 void Delay_ms(int cnt)
  21 {
  22         while(cnt-->0) _delay_ms(1);
  23 }
  24
  25 void active_lines ( void )
  26 {
  27         static uint8_t rept;
  28
  29         _delay_us(4);
  30
  31         asm_render_line();
  32
  33         if( !rept )
  34         {
  35                 if ( buffer_position < ((VRES*hres_bytes)) )
  36                         buffer_position += hres_bytes;
  37                         rept = vres_scale;
  38         }
  39         else rept--;
  40
  41 }
  42
  43 void blank_lines ( void )
  44 {
  45         if ( line < FIRST_LINE )
  46         {
  47                 PORTB ^= 0x004;
  48                 return;
  49         }
  50         line_handler = active_lines;
  51 }
  52
  53 ISR (INT1_vect)
  54 {
  55         line_handler();
  56         line++;
  57         if( line > LAST_LINE)
  58         {
  59                 line = 0;
  60                 buffer_position = 0;
  61                 line_handler = &blank_lines;
  62                 EIMSK &= ~(uint8_t)(1<<INT1);
  63         }
  64 }
  65
  66 ISR (INT0_vect)
  67 {
  68         // VSync is getting close to done.
  69         // Set line-handler to blank-handler to count-up the undesired lines,
  70         // and enable HSync interrupts.
  71
  72         line_handler = &blank_lines;
  73
  74         EIMSK |= (1<<INT1);
  75
  76 }
  77
  78 //Main Function
  79 int main(void)
  80 {
  81
  82         // Note: PB0 is used as CLKO outputting 20MHz clock to ATtiny
  83
  84         // Using some pins on PORTB for debug-indicator-LEDs
  85         DDRB = (1 << PB1)|(1 << PB2);
  86         PORTB = 0x0;
  87
  88         // Using pin 7 on PD to clock out pixels \o/
  89         DDRD = (1<<PD7);
  90         PORTD = 0x0;
  91
  92         /* LM1881 pins are connected to:
  93         INT0 / PCINT18 / PD2 <- VSYNC
  94         INT1 / PCINT19 / PD3 <- CSYNC
  95         PCINT20 / PD4        <- ODD/EVEN
  96         */
  97         EICRA |= (1<<ISC01)|(1<<ISC00); // Select Rising-edge interrupt for VSync
  98         EICRA |= (1<<ISC11)|(1<<ISC10); // Select Rising-edge interrupt for HSync
  99         EIMSK |= (1<<INT0); // Enable VSync-interrupts
 100
 101         // And enable interrupts globally.
 102         sei();
 103
 104         // Allocate the framebuffer :D
 105         screen_buffer = (uint8_t*) malloc( hres_bytes * VRES * sizeof(uint8_t) );
 106         // And make sure it's cleared
 107         fill(c_BLACK);
 108
 109         // Do some static drawing :P
 110         set_pixel(28, 8, 1);
 111         set_pixel(92, 82, 1);
 112
 113         set_pixel(92, 8, 1);
 114         set_pixel(28, 82, 1);
 115
 116
 117         draw_line(0, 0, 128, 92, 1);
 118         draw_line(128, 0, 0, 92, 1);
 119
 120         draw_rect( 0, 1, 127, 91, 1);
 121
 122         draw_rect( 34, 21, 60, 50, 1);
 123         _draw_rect( 24, 11, 80, 70, 1, -1);
 124         draw_rect( 34, 21, 60, 50, 1);
 125
 126
 127         _draw_circle( 64,46, 35, 1, -1 );
 128         draw_circle( 64,46, 30, 1 );
 129         fill_circle( 64,46, 25, 1 );
 130         fill_circle( 64,46, 20, 0 );
 131         fill_rect( 44, 31, 40, 30, 1);
 132         fill_rect( 54, 41, 20, 10, 0);
 133
 134         for (;;)
 135         {
 136                 PORTB ^= 0x002;
 137
 138                 for ( int j = 8; j < 89; j++ )
 139                 {
 140                         draw_line(8,88-j,120,j, 2);
 141                         draw_line(120,j,8,88-j, 2);
 142                         Delay_ms(5);
 143                         draw_line(8,88-j,120,j, 2);
 144                         Delay_ms(5);
 145                 }
 146                 Delay_ms(150);
 147         }
 148 }
 149
 150
 151