old-DasOS/prototypes/video/init.cpp

#include <inttypes.h>

#include "multiboot.h"

#include "../base/include/io.hpp"

struct dummy;

// Symbols generated by linker, no useful content in there...
extern dummy kernelStartMarker;
extern dummy kernelEndMarker;

uint16_t * video = (uint16_t*)0xB8000;

// Prüft, ob man bereits schreiben kann
static uint8_t is_transmit_empty(uint16_t base) {
	return inb(base+5) & 0x20;
}
 
 // Byte senden
static void write_com(uint16_t base, uint8_t chr) {
	while (is_transmit_empty(base)==0);
	outb(base,chr);
}

#define VBE_FAR(name) uint32_t name;

struct ModeInfoBlock {
  uint16_t attributes;
  uint8_t winA,winB;
  uint16_t granularity;
  uint16_t winsize;
  uint16_t segmentA, segmentB;
  VBE_FAR(realFctPtr);
  uint16_t pitch; // bytes per scanline
 
  uint16_t Xres, Yres;
  uint8_t Wchar, Ychar, planes, bpp, banks;
  uint8_t memory_model, bank_size, image_pages;
  uint8_t reserved0;
 
  uint8_t red_mask, red_position;
  uint8_t green_mask, green_position;
  uint8_t blue_mask, blue_position;
  uint8_t rsv_mask, rsv_position;
  uint8_t directcolor_attributes;
 
  uint32_t physbase;  // your LFB (Linear Framebuffer) address ;)
  uint32_t reserved1;
  uint16_t reserved2;
} __attribute__((packed));

#include "pixelschrift.h"

static ModeInfoBlock mib;

static void setpixel(int x, int y, uint32_t color)
{
	uint8_t *fb = (uint8_t*)mib.physbase;

	fb[mib.pitch * y + 4 * x + 2] = (color >>  0) & 0xFF;
	fb[mib.pitch * y + 4 * x + 1] = (color >>  8) & 0xFF;
	fb[mib.pitch * y + 4 * x + 0] = (color >> 16) & 0xFF;
}

static char getDigit(uint32_t i)
{
  if(i >= 0 && i <= 9) {
    return '0' + i;
  }
  return 'A' + (i-10);
}

static void print_str(int x, int y, const char *text)
{
	const unsigned char *base = &MagickImage[10]; // HACKS!
	int cx = x;
	int cy = y;
	while(*text)
	{
		char c = *text++;
		
		int gx = c % 32;
		int gy = 8 * (c / 32);
		
		for(int py = 0; py < 8; py++)
		{
			unsigned char row = base[32 * (gy+py) + gx];
			for(int px = 0; px < 8; px++)
			{
				if((row & (1<<px)) == 0)
					continue;
				setpixel(cx + 6 - px, cy + py, 0xFFFFFF);
			}
		}
		
		cx += 6;
		cy += 0;
	
	}
}

size_t toString(
  char *buffer, 
  size_t length, 
  uint32_t number, 
  uint32_t radix)
{
  if(length == 0) {
    return 0;
  }
  if(number == 0) {
    buffer[0] = '0';
		buffer[1] = '\0';
    return 1;
  }

  size_t len = 0;
  while(number > 0)
  {
    buffer[len++] = getDigit(number % radix);
    if(len >= length)
      break;
    number /= radix;
  }
  
  int half = len / 2;
  for(int i = 0; i < half; i++)
  {
    char c = buffer[i];
    buffer[i] = buffer[len - i - 1];
    buffer[len - i - 1] = c;
  }
	
	buffer[len] = 0;
  
  return len;
}

void strcpy(char *dst, const char *src)
{
	while((*dst++ = *src++));
}

void strcat(char *buffer, const char *text)
{
	while(*buffer++); // scroll to buffer end
	buffer--;
	while((*(buffer++) = *text++)); // copy text
}

void putppm(int x, int y, unsigned char ppm[])
{
	auto *base = &ppm[15];
	for(int py = 0; py < 300; py++)
	{
		for(int px = 0; px < 300; px++)
		{
			uint32_t pixel = 0;
			
			pixel |= (base[900 * py + 3 * px + 0] <<  0);
			pixel |= (base[900 * py + 3 * px + 1] <<  8);
			pixel |= (base[900 * py + 3 * px + 2] << 16);
		
			setpixel(x + px, y + py, pixel);
		}
	}
}

#include "picture.h"

extern "C" void init(multiboot_info_t const & data)
{
	const char *msg = "You should not see this.";
	while(*msg)
	{
		*(video++) = *msg++ | 0x0700;
	}
	
	mib = *(ModeInfoBlock*)data.vbe_mode_info;
	
	for(int y = 0; y < mib.Yres; y++)
	{
		for(int x = 0; x < mib.Xres; x++)
		{
			uint32_t r = x % 256;
			uint32_t g = y % 256;
			uint32_t b = 0x00;
			
			setpixel(x, y, r | (g << 8) | (b << 16));
		}
	}
	
	write_com(0x3F8, 'H');
	write_com(0x3F8, 'i');
	write_com(0x3F8, '\n');
	
	const char *str = (const char*)MagickImage;
	while(*str) {
		write_com(0x3F8, *str++);
	}
	write_com(0x3F8, '\n');
	
	print_str(16, 16, "Hello World!");
	
	char buffer[256];
	char temp[128];
	strcpy(buffer, "X: ");
	toString(temp, 128, mib.Xres, 10); strcat(buffer, temp);
	strcat(buffer, " Y: ");
	toString(temp, 128, mib.Yres, 10); strcat(buffer, temp);
	print_str(16, 24, buffer);
	
	strcpy(buffer, "Pitch: ");
	toString(temp, 128, mib.pitch, 10); strcat(buffer, temp);
	strcat(buffer, " / ");
	toString(temp, 128, mib.pitch / 4, 10); strcat(buffer, temp);
	print_str(16, 32, buffer);
	
	putppm(256, 16, Picture);
	
	write_com(0x3F8, 'B');
	write_com(0x3F8, 'y');
	write_com(0x3F8, 'e');
	write_com(0x3F8, '\n');
	
	
	while(true);
}