Files
bare-metal-pi/includes/kernel/util.c
T
2016-10-19 00:23:03 -07:00

43 lines
1.1 KiB
C

/**
arm-016-util.c
*/
#include "util.h"
void setColor(volatile unsigned char* fb, colour_t pixel, long x, long y, long pitch)
{
int pixel_offset = ( x * ( SCREEN_DEPTH >> 3 ) ) + ( y * pitch );
int r = (int)( pixel.r * 0xFF ) & 0xFF;
int g = (int)( pixel.g * 0xFF ) & 0xFF;
int b = (int)( pixel.b * 0xFF ) & 0xFF;
int a = (int)( pixel.a * 0xFF ) & 0xFF;
if( SCREEN_DEPTH == 32 )
{
/* Four bytes to write */
fb[ pixel_offset++ ] = r;
fb[ pixel_offset++ ] = g;
fb[ pixel_offset++ ] = b;
fb[ pixel_offset++ ] = a;
}
else if( SCREEN_DEPTH == 24 )
{
/* Three bytes to write */
fb[ pixel_offset++ ] = r;
fb[ pixel_offset++ ] = g;
fb[ pixel_offset++ ] = b;
}
else if( SCREEN_DEPTH == 16 )
{
/* Two bytes to write */
/* Bit pack RGB565 into the 16-bit pixel offset */
*(unsigned short*)&fb[pixel_offset] = ( (r >> 3) << 11 ) | ( ( g >> 2 ) << 5 ) | ( b >> 3 );
}
else
{
/* Palette mode. TODO: Work out a colour scheme for
packing rgb into an 8-bit palette! */
}
}