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Basic dda testing

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This commit is contained in:
hodasemi 2019-05-18 20:18:18 +02:00
parent 4d476b510b
commit 4ddcbccd01
1 changed files with 84 additions and 15 deletions
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79
exercise2/src/dda_line_tool.cpp
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@ -6,6 +6,7 @@
#include "dda_line_tool.h"
#include <algorithm>
#include <iostream>
// Initialize the tool and store a reference of a canvas_buffer
dda_line_tool::dda_line_tool(canvas_buffer &canvas) : tool_base(canvas)
@ -13,9 +14,6 @@ dda_line_tool::dda_line_tool(canvas_buffer& canvas): tool_base(canvas)
shape = TS_LINE;
}
// Draw a line from (x0, y0) to (x1, y1)
void dda_line_tool::draw(int x0, int y0, int x1, int y1)
{
@ -29,15 +27,86 @@ void dda_line_tool::draw(int x0, int y0, int x1, int y1)
Aufgabe 3.1.1. Implementieren Sie den DDA-Algorithmus um eine Linie von
(x0, y0) nach (x1, y1) zu rastern. Verwenden Sie
"canvas.set_pixel(x, y)" um einen Pixel zu setzen, wobei
"x" und "y" den gewünschten Pixelpositionen entsprechen.
"x" und "y" den gew<EFBFBD>nschten Pixelpositionen entsprechen.
Diese Methode behandelt auch Randverletzungen. Stellen Sie zunaechst
den Standardfall her. Falls Sie den Wert zweier Variablen vertauschen
muessen koennen Sie dafür die Methode "std::swap(a, b)" verwenden.
muessen koennen Sie daf<EFBFBD>r die Methode "std::swap(a, b)" verwenden.
*************/
/*
int tmp;
// check all different cases
// mirror on x-achsis (y -> -y)
if (x0 < x1 && y0 > y1)
{
y0 = -y0;
y1 = -y1;
float y = static_cast<float>(y0);
float m = static_cast<float>(y1 - y0) / static_cast<float>(x1 - x0);
// '<=' - because we need to include x1 as end location
for (int x = x0; x <= x1; x++)
{
int i_y = static_cast<int>(y + 0.5f);
// (y -> -y)
canvas.set_pixel(x, -i_y);
y += m;
}
}
// rotate by 90° (x <-> -y)
else if (x0 > x1 && y0 < y1)
{
tmp = x0;
x0 = -y0;
y0 = tmp;
tmp = x1;
x1 = -y1;
y1 = tmp;
float y = static_cast<float>(y0);
float m = static_cast<float>(y1 - y0) / static_cast<float>(x1 - x0);
// '<=' - because we need to include x1 as end location
for (int x = x0; x <= x1; x++)
{
int i_y = static_cast<int>(y + 0.5f);
// (x <-> -y)
canvas.set_pixel(-i_y, x);
y += m;
}
}
// mirror on main diagonal (x <-> y)
else if (x)
{
}
// standard
else
{
*/
if (x0 > x1)
{
std::swap(x0, x1);
std::swap(y0, y1);
}
float m = static_cast<float>(y1 - y0) / static_cast<float>(x1 - x0);
std::cout << "anstieg " << m << std::endl;
float y = static_cast<float>(y0);
for (int x = x0; x < x1; x++)
{
canvas.set_pixel(x, static_cast<int>(y + 0.5f));
y += m;
}
//}
}
// Put debug output into the stream "stream" to be displayed in the
// main window