diff options
Diffstat (limited to 'plugingui/pixelbuffer.cc')
| -rw-r--r-- | plugingui/pixelbuffer.cc | 56 |
1 files changed, 41 insertions, 15 deletions
diff --git a/plugingui/pixelbuffer.cc b/plugingui/pixelbuffer.cc index 15270af..bbef84c 100644 --- a/plugingui/pixelbuffer.cc +++ b/plugingui/pixelbuffer.cc @@ -28,7 +28,10 @@ #include <cassert> -namespace GUI { +#include <cstdlib> + +namespace GUI +{ PixelBuffer::PixelBuffer(size_t width, size_t height) : buf(nullptr) @@ -59,13 +62,26 @@ void PixelBuffer::setPixel(size_t x, size_t y, assert(x < width); assert(y < height); - unsigned int a = alpha; - unsigned int b = 255 - alpha; + if(alpha == 0) + { + return; + } - buf[PX(0)] = (unsigned char)(((int)red * a + (int)buf[PX(0)] * b) / 255); - buf[PX(1)] = (unsigned char)(((int)green * a + (int)buf[PX(1)] * b) / 255); - buf[PX(2)] = (unsigned char)(((int)blue * a + (int)buf[PX(2)] * b) / 255); + if(alpha < 255) + { + unsigned int a = alpha; + unsigned int b = 255 - alpha; + buf[PX(0)] = (unsigned char)(((int)red * a + (int)buf[PX(0)] * b) / 255); + buf[PX(1)] = (unsigned char)(((int)green * a + (int)buf[PX(1)] * b) / 255); + buf[PX(2)] = (unsigned char)(((int)blue * a + (int)buf[PX(2)] * b) / 255); + } + else + { + buf[PX(0)] = red; + buf[PX(1)] = green; + buf[PX(2)] = blue; + } } PixelBufferAlpha::PixelBufferAlpha(size_t width, size_t height) @@ -133,17 +149,27 @@ void PixelBufferAlpha::addPixel(size_t x, size_t y, return; } - float a, b; - getAlpha(alpha, buf[PX(3)], a, b); + if(alpha < 255) + { + float a, b; + getAlpha(alpha, buf[PX(3)], a, b); - buf[PX(0)] = (unsigned char)((float)red * a + (float)buf[PX(0)] * b); - buf[PX(0)] /= (a + b); - buf[PX(1)] = (unsigned char)((float)green * a + (float)buf[PX(1)] * b); - buf[PX(1)] /= (a + b); - buf[PX(2)] = (unsigned char)((float)blue * a + (float)buf[PX(2)] * b); - buf[PX(2)] /= (a + b); + buf[PX(0)] = (unsigned char)((float)red * a + (float)buf[PX(0)] * b); + buf[PX(0)] /= (a + b); + buf[PX(1)] = (unsigned char)((float)green * a + (float)buf[PX(1)] * b); + buf[PX(1)] /= (a + b); + buf[PX(2)] = (unsigned char)((float)blue * a + (float)buf[PX(2)] * b); + buf[PX(2)] /= (a + b); - buf[PX(3)] = (a + b) * 255; + buf[PX(3)] = (a + b) * 255; + } + else + { + buf[PX(0)] = red; + buf[PX(1)] = green; + buf[PX(2)] = blue; + buf[PX(3)] = alpha; + } } void PixelBufferAlpha::addPixel(size_t x, size_t y, const Colour& c) |