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
  40                 rept--;
  41
  42 }
  43
  44 void blank_lines ( void )
  45 {
  46         if ( line < FIRST_LINE )
  47         {
  48                 PORTB ^= 0x001;
  49                 return;
  50         }
  51         line_handler = active_lines;
  52 }
  53
  54 ISR (INT1_vect)
  55 {
  56         line_handler();
  57         line++;
  58         if( line > LAST_LINE)
  59         {
  60                 line = 0;
  61                 buffer_position = 0;
  62                 line_handler = &blank_lines;
  63                 EIMSK &= ~(uint8_t)(1<<INT1);
  64         }
  65 }
  66
  67 ISR (INT0_vect)
  68 {
  69         // VSync is getting close to done.
  70         // Set line-handler to blank-handler to count-up the undesired lines,
  71         // and enable HSync interrupts.
  72
  73         line_handler = &blank_lines;
  74
  75         EIMSK |= (1<<INT1);
  76
  77 }
  78
  79 //Main Function
  80 int main(void)
  81 {
  82
  83         // Using some pins on PORTB for debug-indicator-LEDs
  84         DDRB = (1<< PB0)|(1 << PB1)|(1 << PB2);
  85         PORTB = 0x0;
  86
  87         // Using pin 7 on PD to clock out pixels \o/
  88         DDRD = (1<<PD7);
  89         PORTD = 0x0;
  90
  91         /* LM1881 pins are connected to:
  92         INT0 / PCINT18 / PD2 <- VSYNC
  93         INT1 / PCINT19 / PD3 <- CSYNC
  94         PCINT20 / PD4        <- ODD/EVEN
  95         */
  96         EICRA |= (1<<ISC01)|(1<<ISC00); // Select Rising-edge interrupt for VSync
  97         EICRA |= (1<<ISC11)|(1<<ISC10); // Select Rising-edge interrupt for HSync
  98         EIMSK |= (1<<INT0); // Enable VSync-interrupts
  99
 100         // And enable interrupts globally.
 101         sei();
 102
 103         // Allocate the framebuffer :D
 104         screen_buffer = (uint8_t*) malloc( hres_bytes * VRES * sizeof(uint8_t) );
 105         // And make sure it's cleared
 106         fill(c_BLACK);
 107
 108         // Do some static drawing :P
 109         set_pixel(28, 8, 1);
 110         set_pixel(92, 82, 1);
 111
 112         set_pixel(92, 8, 1);
 113         set_pixel(28, 82, 1);
 114
 115
 116         draw_line(0, 0, 128, 92, 1);
 117         draw_line(128, 0, 0, 92, 1);
 118
 119         draw_rect( 0, 1, 127, 91, 1);
 120
 121         draw_rect( 34, 21, 60, 50, 1);
 122         _draw_rect( 24, 11, 80, 70, 1, -1);
 123         draw_rect( 34, 21, 60, 50, 1);
 124
 125
 126         _draw_circle( 64,46, 35, 1, -1 );
 127         draw_circle( 64,46, 30, 1 );
 128         fill_circle( 64,46, 25, 1 );
 129         fill_circle( 64,46, 20, 0 );
 130         fill_rect( 44, 31, 40, 30, 1);
 131         fill_rect( 54, 41, 20, 10, 0);
 132
 133         for (;;)
 134         {
 135                 PORTB ^= 0x002;
 136
 137                 for ( int j = 8; j < 89; j++ )
 138                 {
 139                         draw_line(8,88-j,120,j, 2);
 140                         draw_line(120,j,8,88-j, 2);
 141                         Delay_ms(5);
 142                         draw_line(8,88-j,120,j, 2);
 143                         Delay_ms(5);
 144                 }
 145                 Delay_ms(150);
 146         }
 147 }
 148
 149
 150