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#include "pixelbuffer.h"
#include <stdio.h>
GUI::PixelBuffer::PixelBuffer(size_t width, size_t height)
{
buf = NULL;
realloc(width, height);
}
void GUI::PixelBuffer::realloc(size_t width, size_t height)
{
if(buf) free(buf);
buf = (unsigned char *)calloc(width * height, 3);
this->width = width;
this->height = height;
}
#define PX(k) (x + y * width) * 3 + k
void GUI::PixelBuffer::setPixel(size_t x, size_t y,
unsigned char red,
unsigned char green,
unsigned char blue,
unsigned char alpha)
{
if(x >= width || y >= height) return;
float a = alpha / 255.0;
buf[PX(0)] = (unsigned char)(red * a + buf[PX(0)] * (1-a));
buf[PX(1)] = (unsigned char)(green * a + buf[PX(1)] * (1-a));
buf[PX(2)] = (unsigned char)(blue * a + buf[PX(2)] * (1-a));
}
static int idx = 0;
GUI::PixelBufferAlpha::PixelBufferAlpha(size_t width, size_t height)
{
this->idx = ::idx++;
buf = NULL;
x = y = 10;
realloc(width, height);
}
void GUI::PixelBufferAlpha::realloc(size_t width, size_t height)
{
if(buf) free(buf);
buf = (unsigned char *)calloc(width * height, 4);
this->width = width;
this->height = height;
}
#undef PX
#define PX(k) (x + y * width) * 4 + k
void GUI::PixelBufferAlpha::setPixel(size_t x, size_t y,
unsigned char red,
unsigned char green,
unsigned char blue,
unsigned char alpha)
{
if(x >= width || y >= height) return;
buf[PX(0)] = red;
buf[PX(1)] = green;
buf[PX(2)] = blue;
buf[PX(3)] = alpha;
}
void GUI::PixelBufferAlpha::addPixel(size_t x, size_t y,
unsigned char red,
unsigned char green,
unsigned char blue,
unsigned char alpha)
{
if(x >= width || y >= height) return;
if(alpha == 0) return;
float a = (float)alpha / (float)(alpha + buf[PX(3)]);
buf[PX(0)] = (unsigned char)(red * a + buf[PX(0)] * (1-a));
buf[PX(1)] = (unsigned char)(green * a + buf[PX(1)] * (1-a));
buf[PX(2)] = (unsigned char)(blue * a + buf[PX(2)] * (1-a));
buf[PX(3)] = alpha>buf[PX(3)]?alpha:buf[PX(3)];
}
void GUI::PixelBufferAlpha::pixel(size_t x, size_t y,
unsigned char *red,
unsigned char *green,
unsigned char *blue,
unsigned char *alpha)
{
if(x > width || y > height) return;
*red = buf[PX(0)];
*green = buf[PX(1)];
*blue = buf[PX(2)];
*alpha = buf[PX(3)];
}
#ifdef TEST_PIXELBUFFER
#include "test.h"
TEST_BEGIN;
TEST_END;
#endif
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