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Code: Select all

.set ALIGN,    1<<0             
.set MEMINFO,  1<<1 
.set VIDINFO,  1<<2
.set FLAGS,    ALIGN | MEMINFO | VIDINFO
.set MAGIC,    0x1BADB002       
.set CHECKSUM, -(MAGIC + FLAGS)

#the multiboot header
.section .multiboot
.align 4
.long MAGIC
.long FLAGS
.long CHECKSUM
.long 0, 0, 0, 0, 0
.long 0 #set graphics mode
.long 640, 400, 8  #width, height, depth

.section .bootstrap_stack, "aw", @nobits
stack_bottom:
.skip 16384 # 16 KiB
stack_top:

.section .text
.global _start
.type _start, @function
_start:

	movl $stack_top, %esp

	call kernel_main

	cli
	hlt
.Lhang:
	jmp .Lhang


.size _start, . - _start

Code: Select all

#ifndef VGA_H
#define VGA_H


/* Hardware 8-bit color constants. */
enum vga_color {
	COLOR_BLACK = 0,
	COLOR_BLUE = 1,
	COLOR_GREEN = 2,
	COLOR_CYAN = 3,
	COLOR_RED = 4,
	COLOR_MAGENTA = 5,
	COLOR_BROWN = 6,
	COLOR_LIGHT_GREY = 7,
	COLOR_DARK_GREY = 8,
	COLOR_LIGHT_BLUE = 9,
	COLOR_LIGHT_GREEN = 10,
	COLOR_LIGHT_CYAN = 11,
	COLOR_LIGHT_RED = 12,
	COLOR_LIGHT_MAGENTA = 13,
	COLOR_LIGHT_BROWN = 14,
	COLOR_WHITE = 15,
};

#define Video_Width  640
#define Video_Height 400

typedef uint8_t pixel;

void putpixel(int x,int y, int color);
void graphics_clear(int color);
void graphics_fillrect(size_t x, size_t y, size_t width, size_t height, int color);
// WARNING ----- Will have to be updated for different screen resolution
void graphics_rect(size_t x, size_t y, size_t width, size_t height, int color);
void graphics_drawline(size_t x1, size_t y1, size_t x2, size_t y2, int color);
void graphics_bitmap( int x, int y, int width, int height, uint8_t *data, int forecolor, int backcolor);
void graphics_char( int x, int y, char ch, int forecolor, int backcolor);
void graphics_string( int x, int y, const char *ch, int forecolor, int backcolor);
void graphics_init();

#endif

Code: Select all

#include "system.h"
#include "font.h"

//===============GRAPHICS====================
const size_t memory_location = 0xA0000;
const size_t pitch = 1;

pixel* graphics_buffer;

void putpixel(int x,int y, int color) {
    unsigned where = x*pitch + y*Video_Width*pitch;
    graphics_buffer[where] = color;
}

void graphics_clear(int color)
{
	for (size_t y = 0; y < Video_Height; y++) {
		for (size_t x = 0; x < Video_Width; x++) {
			putpixel(x, y, color);
		}
	}
}

void graphics_fillrect(size_t x, size_t y, size_t width, size_t height, int color)
{
	for (size_t ypos = y; ypos < (y+height); ypos++) {
		for (size_t xpos = x; xpos < (x+width); xpos++) {
			putpixel(xpos, ypos, color);
		}
	}
}


// WARNING ----- Will have to be updated for different screen resolution
void graphics_rect(size_t x, size_t y, size_t width, size_t height, int color)
{
	unsigned where = x*pitch + y*Video_Width*pitch;
    graphics_buffer[where] = color;
    for(size_t top=0; top < width; top++)
    {
    	graphics_buffer[where+top] = color;
    }
    for(size_t lside=0; lside < height; lside++)
    {
    	graphics_buffer[where+(lside*Video_Width)] = color;
    }
    for(size_t rside=0; rside < height; rside++)
    {
    	graphics_buffer[where+width+(rside*Video_Width)] = color;
    }
    for(size_t bottom=0; bottom < width; bottom++)
    {
    	graphics_buffer[where+bottom + Video_Width*height] = color;
    }

}

void graphics_drawline(size_t x1, size_t y1, size_t x2, size_t y2, int color)
{
	double xpos = (double)x1;
	double ypos = (double)y1;
	double xdir=(double)x2-(double)x1;
	double ydir=(double)y2-(double)y1;

    double length = sqroot(sqr(xdir)+sqr(ydir));

    if (length != 0){
        xdir = xdir/length;
        ydir = ydir/length;
    }
    while(true)
	{
		if (sqroot(sqr(xpos-(double)x1)+sqr(ypos-(double)y1)) >= length)
			break;
		putpixel(xpos, ypos, color);
		xpos += xdir;
		ypos += ydir;
	}
}

void graphics_bitmap( int x, int y, int width, int height, uint8_t *data, int forecolor, int backcolor)
{
	int i,j,b;
	int value;

	b=0;

	for(j=0;j<height;j++) {
		for(i=0;i<width;i++) {
			value = ((*data)<<b)&0x80;
			if(value) {
				putpixel(x+i,y+j,forecolor);
			} else {
				putpixel(x+i,y+j,backcolor);
			}
			b++;
			if(b==8) {
				data++;
				b=0;
			}
		}
	}
}

void graphics_char( int x, int y, char ch, int forecolor, int backcolor)
{
  int u = ((int)ch)*FONT_WIDTH*FONT_HEIGHT/8;
	return graphics_bitmap(x,y,FONT_WIDTH,FONT_HEIGHT,&fontdata[u],forecolor,backcolor);
}

void graphics_string( int x, int y, const char *ch, int forecolor, int backcolor)
{
	int _char=0;
	while(*ch) {
		graphics_char( x + _char*8, y, *ch, forecolor, backcolor);
		ch++;
		_char++;
	}
}

void graphics_init() {
	graphics_buffer = (pixel*) memory_location;
	graphics_clear(256);
  //can't use printf because its not initialized yet
  graphics_string(0, 0, "vga: ready\n", COLOR_RED, COLOR_BLACK);
}