betty/display.c

   1 /*
   2  * display.c - handling the display
   3  *
   4  * author: hackbard@hackdaworld.org
   5  *
   6  */
   7
   8 /*
   9  * some comments on alpha blending!
  10  * ################################
  11  *
  12  * if c is the result of layer a over layer b with opacity alpha:
  13  *
  14  * c=alpha*a+(1-alpha)*b and if alpha is a byte (0-255)
  15  * => c=alpha*a+(255-alpha)*b
  16  *
  17  */
  18
  19 #include "display.h"
  20 #include "system.h"
  21 #include "default_logo.h"
  22 #include "uart.h"
  23
  24 /*
  25  * functions
  26  */
  27
  28 void display_fill_screen(u8 fill) {
  29
  30         u8 page,width;
  31         u8 buf[2];
  32
  33         buf[0]=0;
  34         buf[1]=0;
  35
  36         switch(fill) {
  37                 case DISPLAY_FILL_LG:
  38                         buf[1]=0xff;
  39                         break;
  40                 case DISPLAY_FILL_DG:
  41                         buf[0]=0xff;
  42                         break;
  43                 case DISPLAY_FILL_B:
  44                         buf[0]=0xff;
  45                         buf[1]=0xff;
  46                         break;
  47                 case DISPLAY_FILL_W:
  48                 default:
  49                         break;
  50         }
  51
  52         for(page=0;page<DISPLAY_PAGE_MAX;page++) {
  53                 DISPLAY_SET_C_ADDR(0);
  54                 DISPLAY_SET_PAGE_ADDR(page);
  55                 for(width=0;width<DISPLAY_DIMX;width++) {
  56                         DISPLAY_DATA=buf[0];
  57                         DISPLAY_DATA=buf[1];
  58                 }
  59         }
  60 }
  61
  62 void display_clear_screen(void) {
  63
  64         display_fill_screen(DISPLAY_FILL_W);
  65 }
  66
  67 void display_init(void) {
  68
  69         /* oscillator, regulator, boost, opamp, contrast */
  70         DISPLAY_START_OSCILLATOR;
  71         DISPLAY_SET_REGULATOR(7);
  72         DISPLAY_SET_CONTRAST(0x38);
  73         DISPLAY_SET_CONV_FACTOR(0x01);
  74         DISPLAY_SET_POWER(DISPLAY_V_BOOST|DISPLAY_REGULATOR|DISPLAY_OPAMP);
  75
  76         // gray scale palette
  77         DISPLAY_SET_WHITE(0,0,0,0);
  78         DISPLAY_SET_LGRAY(5,5,5,5);     // obviously 3, but it's too bright!
  79         DISPLAY_SET_DGRAY(7,7,7,7);     // obviously 6, but again too bright!
  80         DISPLAY_SET_BLACK(9,9,9,9);
  81
  82         /* normal mode, display depending ram content */
  83         DISPLAY_RAM_CONTENTS_ON;
  84         display_clear_screen();
  85         DISPLAY_NORMAL;                 // 00 -> white, 11 -> black
  86         DISPLAY_SET_COM_ODIR_REMAPPED;  // start counting at the top
  87
  88         /* switch on the display */
  89         DISPLAY_SET_ON;
  90 }
  91
  92 void display_load_logo(u8 *src) {
  93
  94         u8 *s;
  95         u8 page,width;
  96
  97         s=src;
  98         if(s==0)
  99                 s=default_logo;
 100
 101         for(page=0;page<DISPLAY_PAGE_MAX;page++) {
 102                 DISPLAY_SET_C_ADDR(0);
 103                 DISPLAY_SET_PAGE_ADDR(page);
 104                 for(width=0;width<DISPLAY_DIMX;width++) {
 105                         DISPLAY_DATA=*s++;
 106                         DISPLAY_DATA=*s++;
 107                 }
 108         }
 109 }
 110
 111 #define display_m2i(m,r) (((((m)[0]>>r)&1)<<1)|(((m)[1]>>r)&1))
 112
 113 void display_draw_rectangle(u8 x,u8 y,u8 w,u8 h,u8 fill,u8 alpha) {
 114
 115         u8 page,col,row,rmax,cnt;
 116         u8 d[2];
 117         int ca,cb;
 118         u8 a,b,c;                       // c = a over b
 119
 120         a=fill&0x03;
 121         ca=0;
 122         for(cnt=0;cnt<a;cnt++)          // contribution of a: alpha*a
 123                 ca+=alpha;
 124
 125         for(page=(y>>3);page<=((y+h)>>3);page++) {      // page = y/8
 126                 DISPLAY_SET_PAGE_ADDR(page);
 127                 rmax=(page+1)<<3;                       // row max
 128                 if(rmax>y+h)
 129                         rmax=y+h;
 130                 for(col=x;col<x+w;col++) {
 131                         DISPLAY_SET_C_ADDR(col);
 132                         d[0]=DISPLAY_DATA;              // dummy read (p.16)
 133                         d[0]=DISPLAY_DATA;
 134                         d[1]=DISPLAY_DATA;
 135                         for(row=y;row<rmax;row++) {
 136                                 // contribution of b: (255-alpha)*b
 137                                 b=display_m2i(d,row);
 138                                 cb=0;
 139                                 for(cnt=0;cnt<b;cnt++)
 140                                         cb+=(255-alpha);
 141                                 // finally there is c
 142                                 c=(ca+cb)>>8;
 143                                 d[0]&=~(1<<row);
 144                                 d[1]&=~(1<<row);
 145                                 d[0]|=((c>>1)&1)<<row;
 146                                 d[1]|=(c&1)<<row;
 147                         }
 148                         DISPLAY_SET_C_ADDR(col);
 149                         DISPLAY_DATA=b[0];
 150                         DISPLAY_DATA=b[1];
 151                 }
 152                 y=rmax;
 153         }
 154 }
 155
 156 void display_draw_buf(u8 x,u8 y,u8 w,u8 h,u8 *buf,u8 alpha) {
 157
 158 }
 159
 160 void display_bl_init(void) {
 161
 162         IODIR0|=(1<<4);
 163         IOSET0=(1<<4);  // off by default
 164 }
 165
 166 void display_bl_toggle(void) {
 167
 168         if(IOPIN0&(1<<4))
 169                 IOCLR0=(1<<4);
 170         else
 171                 IOSET0=(1<<4);
 172 }
 173
 174 void display_bl_on(void) {
 175
 176         IOCLR0=(1<<4);
 177 }
 178
 179 void display_bl_off(void) {
 180
 181         IOSET0=(1<<4);
 182 }
 183