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Diffstat (limited to 'plugingui/pixelbuffer.cc')
| -rw-r--r-- | plugingui/pixelbuffer.cc | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/plugingui/pixelbuffer.cc b/plugingui/pixelbuffer.cc new file mode 100644 index 0000000..2a6bf6f --- /dev/null +++ b/plugingui/pixelbuffer.cc @@ -0,0 +1,180 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/*************************************************************************** + * pixelbuffer.cc + * + * Thu Nov 10 09:00:38 CET 2011 + * Copyright 2011 Bent Bisballe Nyeng + * deva@aasimon.org + ****************************************************************************/ + +/* + * This file is part of DrumGizmo. + * + * DrumGizmo is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * DrumGizmo is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with DrumGizmo; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + */ +#include "pixelbuffer.h" + +#include <stdio.h> + +GUI::PixelBuffer::PixelBuffer(size_t width, size_t height) +{ + buf = NULL; + realloc(width, height); +} + +GUI::PixelBuffer::~PixelBuffer() +{ + if(buf) free(buf); +} + +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,b; + getAlpha(alpha, 255, 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); + */ + 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); + +} + +static int idx = 0; +GUI::PixelBufferAlpha::PixelBufferAlpha(size_t width, size_t height) +{ + this->idx = ::idx++; + buf = NULL; + x = y = 10; + realloc(width, height); +} + +GUI::PixelBufferAlpha::~PixelBufferAlpha() +{ + if(buf) free(buf); +} + +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; +} + +// http://en.wikipedia.org/wiki/Alpha_compositing +static void getAlpha(unsigned char _a, unsigned char _b, float &a, float &b) +{ + a = _a / 255.0; + b = _b / 255.0; + b *= (1-a); +} + +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,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(3)] = (a + b) * 255; +} + +void GUI::PixelBufferAlpha::addPixel(size_t x, size_t y, GUI::Colour c) +{ + addPixel(x, y, c.red * 255, c.green * 255, c.blue * 255, c.alpha * 255); +} + +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 +//Additional dependency files +//deps: +//Required cflags (autoconf vars may be used) +//cflags: +//Required link options (autoconf vars may be used) +//libs: +#include "test.h" + +TEST_BEGIN; + +// TODO: Put some testcode here (see test.h for usable macros). + +TEST_END; + +#endif/*TEST_PIXELBUFFER*/ |