Gert van der Knokke / vga640x480g

VGA 640x480 full graphic driver

Dependents:   vga640x480graphic gps_fastlib Chua-VGA Wolfram-1D-VGA ... more

vga640x480g_functions.h@0:821e34a87609, 2011-07-27 (annotated)

Committer:
gertk
Date:
Wed Jul 27 19:43:07 2011 +0000
Revision:
0:821e34a87609
0.1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
gertk 0:821e34a87609 1 #include "vga_font.h"
gertk 0:821e34a87609 2 #define FRAMEBUFFERMAX 32000
gertk 0:821e34a87609 3 #define EXTENSIONMAX 6400
gertk 0:821e34a87609 4 #define VGA_HEIGHT 400
gertk 0:821e34a87609 5 #define VGA_WIDTH 640
gertk 0:821e34a87609 6 #include "mbed.h"
gertk 0:821e34a87609 7
gertk 0:821e34a87609 8 extern unsigned char *framebuffer;
gertk 0:821e34a87609 9 extern unsigned char *framebuffer2;
gertk 0:821e34a87609 10
gertk 0:821e34a87609 11 static const unsigned char rmask[]={0x7f,0xbf,0xdf,0xef,0xf7,0xfb,0xfd,0xfe};
gertk 0:821e34a87609 12 static const unsigned char smask[]={0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01};
gertk 0:821e34a87609 13
gertk 0:821e34a87609 14 // clear the screen
gertk 0:821e34a87609 15 void vga_cls() {
gertk 0:821e34a87609 16 memset(framebuffer,0,FRAMEBUFFERMAX);
gertk 0:821e34a87609 17 memset(framebuffer2,0,EXTENSIONMAX);
gertk 0:821e34a87609 18 }
gertk 0:821e34a87609 19
gertk 0:821e34a87609 20 // scroll the screen one text line up
gertk 0:821e34a87609 21 void vga_scroll() {
gertk 0:821e34a87609 22 // move first part up
gertk 0:821e34a87609 23 memcpy(framebuffer,framebuffer+(FONTHEIGHT*80),FRAMEBUFFERMAX-80*(FONTHEIGHT));
gertk 0:821e34a87609 24 // copy top line of second part into bottom of first part
gertk 0:821e34a87609 25 memcpy(framebuffer+FRAMEBUFFERMAX-80*(FONTHEIGHT),framebuffer2,FONTHEIGHT*80);
gertk 0:821e34a87609 26 // move bottom part up
gertk 0:821e34a87609 27 memcpy(framebuffer2,framebuffer2+(FONTHEIGHT*80),EXTENSIONMAX-80*(FONTHEIGHT));
gertk 0:821e34a87609 28 // clear bottom row of second part
gertk 0:821e34a87609 29 memset(framebuffer2+EXTENSIONMAX-80*(FONTHEIGHT),0,FONTHEIGHT*80);
gertk 0:821e34a87609 30 }
gertk 0:821e34a87609 31
gertk 0:821e34a87609 32 // set or reset a single pixel on screen
gertk 0:821e34a87609 33 void vga_plot(int x,int y,char color) {
gertk 0:821e34a87609 34 unsigned char *ad;
gertk 0:821e34a87609 35
gertk 0:821e34a87609 36 ad=framebuffer+80*y+((x/8)^1); // calculate offset
gertk 0:821e34a87609 37 if (ad>=framebuffer+FRAMEBUFFERMAX) { // first test for end of framebuffer
gertk 0:821e34a87609 38 ad=framebuffer2+80*(y-400)+((x/8)^1); // calculate offset in framebuffer2
gertk 0:821e34a87609 39 if (ad>framebuffer2+EXTENSIONMAX) return; // clip if exceeded
gertk 0:821e34a87609 40 }
gertk 0:821e34a87609 41 *ad &= rmask[x%8]; // clear the bit
gertk 0:821e34a87609 42 if (color) *ad |= smask[x%8]; // if color != 0 set the bit
gertk 0:821e34a87609 43
gertk 0:821e34a87609 44 }
gertk 0:821e34a87609 45
gertk 0:821e34a87609 46 // put a character from the vga font on screen
gertk 0:821e34a87609 47 void vga_putchar(int x,int y,int ch, char color) {
gertk 0:821e34a87609 48 int n,m;
gertk 0:821e34a87609 49 for (n=0; n<FONTHEIGHT; n++) {
gertk 0:821e34a87609 50 for (m=0; m<FONTWIDTH; m++) {
gertk 0:821e34a87609 51 if (vga_font8x16[ch*FONTHEIGHT+n] & (1<<(7-m))) vga_plot(x+m,y+n, color);
gertk 0:821e34a87609 52 else vga_plot(x+m,y+n,0);
gertk 0:821e34a87609 53 }
gertk 0:821e34a87609 54 }
gertk 0:821e34a87609 55 }
gertk 0:821e34a87609 56
gertk 0:821e34a87609 57 // put a string on screen
gertk 0:821e34a87609 58 void vga_putstring(int x,int y, char *s, char color) {
gertk 0:821e34a87609 59 while (*s) {
gertk 0:821e34a87609 60 vga_putchar(x,y,*(s++),color);
gertk 0:821e34a87609 61 x+=FONTWIDTH;
gertk 0:821e34a87609 62 }
gertk 0:821e34a87609 63 }
gertk 0:821e34a87609 64
gertk 0:821e34a87609 65 // Bresenham line routine
gertk 0:821e34a87609 66 void vga_line(int x0, int y0, int x1, int y1,char color) {
gertk 0:821e34a87609 67
gertk 0:821e34a87609 68 char steep=1;
gertk 0:821e34a87609 69 int li,dx,dy,le;
gertk 0:821e34a87609 70 int sx,sy;
gertk 0:821e34a87609 71
gertk 0:821e34a87609 72 // if same coordinates
gertk 0:821e34a87609 73 if (x0==x1 && y0==y1) {
gertk 0:821e34a87609 74 vga_plot(x0,y0,color);
gertk 0:821e34a87609 75 return;
gertk 0:821e34a87609 76 }
gertk 0:821e34a87609 77
gertk 0:821e34a87609 78 dx = abs(x1-x0);
gertk 0:821e34a87609 79 sx = ((x1 - x0) >0) ? 1 : -1;
gertk 0:821e34a87609 80 dy=abs(y1-y0);
gertk 0:821e34a87609 81 sy = ((y1 - y0) >0) ? 1 : -1;
gertk 0:821e34a87609 82
gertk 0:821e34a87609 83 if (dy > dx) {
gertk 0:821e34a87609 84 steep=0;
gertk 0:821e34a87609 85 // swap X0 and Y0
gertk 0:821e34a87609 86 x0=x0 ^ y0;
gertk 0:821e34a87609 87 y0=x0 ^ y0;
gertk 0:821e34a87609 88 x0=x0 ^ y0;
gertk 0:821e34a87609 89
gertk 0:821e34a87609 90 // swap DX and DY
gertk 0:821e34a87609 91 dx=dx ^ dy;
gertk 0:821e34a87609 92 dy=dx ^ dy;
gertk 0:821e34a87609 93 dx=dx ^ dy;
gertk 0:821e34a87609 94
gertk 0:821e34a87609 95 // swap SX and SY
gertk 0:821e34a87609 96 sx=sx ^ sy;
gertk 0:821e34a87609 97 sy=sx ^ sy;
gertk 0:821e34a87609 98 sx=sx ^ sy;
gertk 0:821e34a87609 99 }
gertk 0:821e34a87609 100
gertk 0:821e34a87609 101 le = (dy << 1) - dx;
gertk 0:821e34a87609 102
gertk 0:821e34a87609 103 for (li=0; li<=dx; li++) {
gertk 0:821e34a87609 104 if (steep) {
gertk 0:821e34a87609 105 vga_plot(x0,y0,color);
gertk 0:821e34a87609 106 } else {
gertk 0:821e34a87609 107 vga_plot(y0,x0,color);
gertk 0:821e34a87609 108 }
gertk 0:821e34a87609 109 while (le >= 0) {
gertk 0:821e34a87609 110 y0 += sy;
gertk 0:821e34a87609 111 le -= (dx << 1);
gertk 0:821e34a87609 112 }
gertk 0:821e34a87609 113 x0 += sx;
gertk 0:821e34a87609 114 le += (dy << 1);
gertk 0:821e34a87609 115 }
gertk 0:821e34a87609 116 }
gertk 0:821e34a87609 117
gertk 0:821e34a87609 118 // draw an outline box
gertk 0:821e34a87609 119 void vga_box(int x0, int y0, int x1, int y1,char color) {
gertk 0:821e34a87609 120 vga_line(x0,y0,x1,y0,color);
gertk 0:821e34a87609 121 vga_line(x1,y0,x1,y1,color);
gertk 0:821e34a87609 122 vga_line(x1,y1,x0,y1,color);
gertk 0:821e34a87609 123 vga_line(x0,y1,x0,y0,color);
gertk 0:821e34a87609 124 }
gertk 0:821e34a87609 125
gertk 0:821e34a87609 126 // draw a filled box
gertk 0:821e34a87609 127 void vga_filledbox(int x0, int y0, int x1, int y1,char color) {
gertk 0:821e34a87609 128 int n,dn;
gertk 0:821e34a87609 129
gertk 0:821e34a87609 130 if (y1>y0) dn=1;
gertk 0:821e34a87609 131 else dn=-1;
gertk 0:821e34a87609 132
gertk 0:821e34a87609 133 for (n=abs(y1-y0); n>=0; n--) {
gertk 0:821e34a87609 134 vga_line(x0,y0,x1,y0,color);
gertk 0:821e34a87609 135 y0+=dn;
gertk 0:821e34a87609 136 }
gertk 0:821e34a87609 137 }
gertk 0:821e34a87609 138
gertk 0:821e34a87609 139 // Bresenham circle routine
gertk 0:821e34a87609 140 void vga_circle(int x0,int y0, int radius, char color) {
gertk 0:821e34a87609 141
gertk 0:821e34a87609 142 int cf = 1 - radius;
gertk 0:821e34a87609 143 int dx = 1;
gertk 0:821e34a87609 144 int dy = -2 * radius;
gertk 0:821e34a87609 145 int cx = 0;
gertk 0:821e34a87609 146 int py = radius;
gertk 0:821e34a87609 147
gertk 0:821e34a87609 148 vga_plot(x0, y0 + radius,color);
gertk 0:821e34a87609 149 vga_plot(x0, y0 - radius,color);
gertk 0:821e34a87609 150 vga_plot(x0 + radius, y0,color);
gertk 0:821e34a87609 151 vga_plot(x0 - radius, y0,color);
gertk 0:821e34a87609 152
gertk 0:821e34a87609 153 while (cx < py) {
gertk 0:821e34a87609 154 if (cf >= 0) {
gertk 0:821e34a87609 155 py--;
gertk 0:821e34a87609 156 dy += 2;
gertk 0:821e34a87609 157 cf += dy;
gertk 0:821e34a87609 158 }
gertk 0:821e34a87609 159 cx++;
gertk 0:821e34a87609 160 dx += 2;
gertk 0:821e34a87609 161 cf += dx;
gertk 0:821e34a87609 162 vga_plot(x0 + cx, y0 + py,color);
gertk 0:821e34a87609 163 vga_plot(x0 - cx, y0 + py,color);
gertk 0:821e34a87609 164 vga_plot(x0 + cx, y0 - py,color);
gertk 0:821e34a87609 165 vga_plot(x0 - cx, y0 - py,color);
gertk 0:821e34a87609 166 vga_plot(x0 + py, y0 + cx,color);
gertk 0:821e34a87609 167 vga_plot(x0 - py, y0 + cx,color);
gertk 0:821e34a87609 168 vga_plot(x0 + py, y0 - cx,color);
gertk 0:821e34a87609 169 vga_plot(x0 - py, y0 - cx,color);
gertk 0:821e34a87609 170 }
gertk 0:821e34a87609 171 }