fgrid.cpp

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/*-
 * Copyright (c) 2014-2018 Carsten Sonne Larsen <cs@innolan.net>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Project homepage:
 * https://amath.innolan.net
 * 
 */

#include "fgrid.h"
#include "lib/real.h"

Grid::Grid(UserFunction* function) :
    function(function)
{
    parameter = new RealNumber();
    zoom = 1.0;
    pad = 8;
}

Grid::~Grid()
{
    delete parameter;
}

double Grid::GetHorizontalResolution() const
{
    return (maxX - minX) / (screenMaxX - screenMinX);
}

void Grid::SetFunctionBounderies(double minX, double maxX)
{
    this->minX = minX;
    this->maxX = maxX;
    minY = FunctionValue(minX);
    maxY = FunctionValue(maxX);

    scaleX = (screenMaxX - screenMinX) / (maxX - minX);
    scaleY = (screenMaxY - screenMinY) / (maxY - minY);

    // Keep aspect ratio
    if (scaleX < scaleY)
    {
        scaleX = scaleY;
    }
    else
    {
        scaleY = scaleX;
    }
}

void Grid::SetScreenBounderues(int minX, int maxX, int minY, int maxY)
{
    screenMinX = minX + pad;
    screenMaxX = maxX - pad;
    screenMinY = minY + pad;
    screenMaxY = maxY - pad;

    originX = (screenMaxX - screenMinX) / 2;
    originY = (screenMaxY - screenMinY) / 2;
}

double Grid::FunctionValue(double parameter) const
{
    this->parameter->SetRealValue(parameter);
    function->GetVariable()->AssignValue(this->parameter);
    Number* res = function->GetExpression()->Evaluate();
    double value = res->GetRealValue();
    return value;
}

void Grid::GetScreenCoordinates(double value, int* x, int* y) const
{
    double valueX = value * scaleX * zoom + originX;
    double valueY = FunctionValue(value) * scaleY * zoom + originY;

    *x = valueX < screenMinX || valueX > screenMaxX ? -1 : static_cast<int>(valueX);
    *y = valueY < screenMinY || valueY > screenMaxY ? -1 : static_cast<int>(valueY);
}

void Grid::GetScreenCoordinates(double xval, int* x, double yval, int* y) const
{
    double valueX = xval * scaleX * zoom + originX;
    double valueY = yval * scaleY * zoom + originY;

    *x = valueX < screenMinX || valueX > screenMaxX ? -1 : static_cast<int>(valueX);
    *y = valueY < screenMinY || valueY > screenMaxY ? -1 : static_cast<int>(valueY);
}

void Grid::GetXAxis(int* xstart, int* xend, int* ystart, int* yend) const
{
    *xstart = screenMinX;
    *xend = screenMaxX;
    *ystart = originY;
    *yend = originY;
}

void Grid::GetYAxis(int* xstart, int* xend, int* ystart, int* yend) const
{
    *xstart = originX;
    *xend = originX;
    *ystart = screenMinY;
    *yend = screenMaxY;
}