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/*************************************************************************
* Copyright (C) 2009 Tavian Barnes <tavianator@gmail.com> *
* *
* This file is part of The Dimension Library. *
* *
* The Dimension Library is free software; you can redistribute it and/ *
* or modify it under the terms of the GNU Lesser General Public License *
* as published by the Free Software Foundation; either version 3 of the *
* License, or (at your option) any later version. *
* *
* The Dimension Library 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 *
* Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public *
* License along with this program. If not, see *
* <http://www.gnu.org/licenses/>. *
*************************************************************************/
#include "dimensionxx.hpp"
#include <cstdio>
namespace Dimension
{
GL_Drawer::GL_Drawer(Canvas& canvas)
: m_canvas(&canvas), m_drawn(false)
{
// Optimize the canvas for GL drawing
dmnsn_gl_optimize_canvas(m_canvas->dmnsn());
}
// Draw the canvas if it hasn't been drawn yet
GL_Drawer::~GL_Drawer()
{
if (!m_drawn) {
try {
draw();
} catch (...) {
dmnsn_error(SEVERITY_MEDIUM,
"Drawing canvas to GL failed in GL_Drawer destructor.");
}
}
}
// Draw the canvas to the current openGL buffer
void GL_Drawer::draw()
{
// Draw to the GL buffer
if (dmnsn_gl_write_canvas(m_canvas->dmnsn()) != 0) {
// The drawing operation failed
throw Dimension_Error("Drawing canvas to GL failed.");
}
m_drawn = true; // Don't draw again in destructor
}
// Read a canvas from a GL buffer
Canvas
GL_Reader::read(unsigned int x0, unsigned int y0,
unsigned int width, unsigned int height)
{
// Read the canvas from the GL buffer
dmnsn_canvas* canvas = dmnsn_gl_read_canvas(x0, y0, width, height);
if (!canvas) {
// The read operation failed
throw Dimension_Error("Reading canvas from GL failed.");
}
return Canvas(canvas);
}
}
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