vga640x400g_functions.h

00001 #include "vga_font.h"
00002 #define FRAMEBUFFERMAX 32000
00003 #define VGA_HEIGHT 400
00004 #define VGA_WIDTH 640
00005 #include "mbed.h"
00006 
00007 extern unsigned char *framebuffer;
00008 
00009 static const unsigned char rmask[]={0x7f,0xbf,0xdf,0xef,0xf7,0xfb,0xfd,0xfe};
00010 static const unsigned char smask[]={0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01};
00011 
00012 // clear the screen
00013 void vga_cls() {
00014     memset(framebuffer,0,FRAMEBUFFERMAX);
00015 }
00016 
00017 // scroll the screen one text line up
00018 void vga_scroll() {
00019     memcpy(framebuffer,framebuffer+(FONTHEIGHT*80),FRAMEBUFFERMAX-80*(FONTHEIGHT));
00020     memset(framebuffer+FRAMEBUFFERMAX-80*(FONTHEIGHT),0,FONTHEIGHT*80);
00021 }
00022 
00023 // set or reset a single pixel on screen
00024 void vga_plot(int x,int y,char color) {
00025     unsigned int ad;
00026 
00027     ad=80*y+((x/8)^1);                      // calculate offset
00028     if (ad>=FRAMEBUFFERMAX) return;         // crude clip
00029     framebuffer[ad]&=rmask[x%8];             // clear the bit
00030     if (color) framebuffer[ad]|=smask[x%8]; // if color != 0 set the bit
00031 }
00032 
00033 // put a character from the vga font on screen
00034 void vga_putchar(int x,int y,int ch, char color) {
00035     int n,m;
00036     for (n=0; n<FONTHEIGHT; n++) {
00037         for (m=0; m<FONTWIDTH; m++) {
00038             if (vga_font8x16[ch*FONTHEIGHT+n] & (1<<(7-m))) vga_plot(x+m,y+n, color);
00039             else vga_plot(x+m,y+n,0);
00040         }
00041     }
00042 }
00043 
00044 // put a string on screen
00045 void vga_putstring(int x,int y, char *s, char color) {
00046     while (*s) {
00047         vga_putchar(x,y,*(s++),color);
00048         x+=FONTWIDTH;
00049     }
00050 }
00051 
00052 // Bresenham line routine
00053 void vga_line(int x0, int y0, int x1, int y1,char color) {
00054 
00055     char steep=1;
00056     int li,dx,dy,le;
00057     int sx,sy;
00058 
00059     // if same coordinates
00060     if (x0==x1 && y0==y1) {
00061         vga_plot(x0,y0,color);
00062         return;
00063     }
00064 
00065     dx = abs(x1-x0);
00066     sx = ((x1 - x0) >0) ? 1 : -1;
00067     dy=abs(y1-y0);
00068     sy = ((y1 - y0) >0) ? 1 : -1;
00069 
00070     if (dy > dx) {
00071         steep=0;
00072         // swap X0 and Y0
00073         x0=x0 ^ y0;
00074         y0=x0 ^ y0;
00075         x0=x0 ^ y0;
00076 
00077         // swap DX and DY
00078         dx=dx ^ dy;
00079         dy=dx ^ dy;
00080         dx=dx ^ dy;
00081 
00082         // swap SX and SY
00083         sx=sx ^ sy;
00084         sy=sx ^ sy;
00085         sx=sx ^ sy;
00086     }
00087 
00088     le = (dy << 1) - dx;
00089 
00090     for (li=0; li<=dx; li++) {
00091         if (steep) {
00092             vga_plot(x0,y0,color);
00093         } else {
00094             vga_plot(y0,x0,color);
00095         }
00096         while (le >= 0) {
00097             y0 += sy;
00098             le -= (dx << 1);
00099         }
00100         x0 += sx;
00101         le += (dy << 1);
00102     }
00103 }
00104 
00105 // draw an outline box
00106 void vga_box(int x0, int y0, int x1, int y1,char color) {
00107     vga_line(x0,y0,x1,y0,color);
00108     vga_line(x1,y0,x1,y1,color);
00109     vga_line(x1,y1,x0,y1,color);
00110     vga_line(x0,y1,x0,y0,color);
00111 }
00112 
00113 // draw a filled box
00114 void vga_filledbox(int x0, int y0, int x1, int y1,char color) {
00115     int n,dn;
00116 
00117     if (y1>y0) dn=1;
00118     else dn=-1;
00119 
00120     for (n=abs(y1-y0); n>=0; n--) {
00121         vga_line(x0,y0,x1,y0,color);
00122         y0+=dn;
00123     }
00124 }
00125 
00126 // Bresenham circle routine
00127 void vga_circle(int x0,int y0, int radius, char color) {
00128 
00129     int cf = 1 - radius;
00130     int dx = 1;
00131     int dy = -2 * radius;
00132     int cx = 0;
00133     int py = radius;
00134 
00135     vga_plot(x0, y0 + radius,color);
00136     vga_plot(x0, y0 - radius,color);
00137     vga_plot(x0 + radius, y0,color);
00138     vga_plot(x0 - radius, y0,color);
00139 
00140     while (cx < py) {
00141         if (cf >= 0) {
00142             py--;
00143             dy += 2;
00144             cf += dy;
00145         }
00146         cx++;
00147         dx += 2;
00148         cf += dx;
00149         vga_plot(x0 + cx, y0 + py,color);
00150         vga_plot(x0 - cx, y0 + py,color);
00151         vga_plot(x0 + cx, y0 - py,color);
00152         vga_plot(x0 - cx, y0 - py,color);
00153         vga_plot(x0 + py, y0 + cx,color);
00154         vga_plot(x0 - py, y0 + cx,color);
00155         vga_plot(x0 + py, y0 - cx,color);
00156         vga_plot(x0 - py, y0 - cx,color);
00157     }
00158 }