frednora

// color1 and color2 are R4G4B4 12bit RGB color values, alpha is 0-255
uint16_t blend_12bit( uint16_t color1, uint16_t color2, uint8_t alpha ) {
	uint64_t c1 = (uint64_t) color1;
	uint64_t c2 = (uint64_t) color2;
	uint64_t a = (uint64_t)( alpha >> 4 );
	// bit magic to alpha blend R G B with single mul
	c1 = ( c1 | ( c1 << 12 ) ) & 0x0f0f0f;
	c2 = ( c2 | ( c2 << 12 ) ) & 0x0f0f0f;
	uint32_t o = ( ( ( ( c2 - c1 ) * a ) >> 4 ) + c1 ) & 0x0f0f0f;

frednora

ANSI Escape Sequences

Standard escape codes are prefixed with Escape:

• Ctrl-Key: ^[
• Octal: \033
• Unicode: \u001b
• Hexadecimal: \x1B
• Decimal: 27

frednora

Memory Optimization (Christer Ericson, GDC 2003)
http://realtimecollisiondetection.net/pubs/GDC03_Ericson_Memory_Optimization.ppt

Cache coherency primer (Fabian Giesen)
https://fgiesen.wordpress.com/2014/07/07/cache-coherency/

Code Clinic 2015: How to Write Code the Compiler Can Actually Optimize (Mike Acton)
http://gdcvault.com/play/1021866/Code-Clinic-2015-How-to

frednora

Pico HTTP Server in C

This is a very simple HTTP server for Unix, using fork(). It's very easy to use

How to use

1. include header httpd.h
2. write your route method, handling requests.
3. call serve_forever("12913") to start serving on port 12913

frednora

/*
    Packet sniffer using libpcap library
*/
#include<pcap.h>
#include<stdio.h>
#include<stdlib.h> // for exit()
#include<string.h> //for memset
 
#include<sys/socket.h>
#include<arpa/inet.h> // for inet_ntoa()

frednora

// Exemplo de geração de números aleatórios

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

/*
	A função gerar_numero() retorna um número aleatório
	que pertence ao intervalo [lim_inf, lim_sup]
	

frednora

// Credits:
// Omar Mohammad. Maadi, Cairo, Egypt. (Original in Assembly)
// Wagner Teixeira
// Fred Nora

//==================================================================================
// Start - testing update_mouse
//==================================================================================

#define MOUSE_LEFT_BTN	  0x01

frednora

void 
refresh_rectangle ( unsigned long x, 
                    unsigned long y, 
				    unsigned long width, 
				    unsigned long height )
{    
	void *p = (void *) FRONTBUFFER_ADDRESS;		
	const void *q = (const void*) BACKBUFFER_ADDRESS;

	//#TEST

frednora

void *CreatePageDirectory (){
	
	int i;
	
	unsigned long destAddressVA;  //virtual.
	
	//alocaremos uma página apenas, pois tem 4KB.
	
	destAddressVA = (unsigned long) newPage (); 
	if ( destAddressVA == 0 )

frednora

unsigned long 
virtual_to_physical( unsigned long virtual_address, 
                     unsigned long dir_address ) 
{
	
	unsigned long address;
	
	unsigned long *dir = (unsigned long *) dir_address;

	unsigned long tmp;