GLSL Shaders -> Files (instead of #define)

[ipdf/code.git] / src / tests / lines.cpp

diff --git a/src/tests/lines.cpp b/src/tests/lines.cpp
new file mode 100644 (file)
index 0000000..b15d218
--- /dev/null
+++ b/src/tests/lines.cpp
@@ -0,0 +1,76 @@
+#include "main.h"
+
+#include "pointstobitmap.h"
+
+using namespace std;
+
+/**
+ * NOTE: I am using vector<pair<T,T> > because it is convenient; don't have to round to pixels, can print to stdout and gnuplot, etc
+ *             vector<pair<T,T> > should obviously not be used in a practical implementation; directly access the pixel buffer
+ */
+
+template <class T> vector<pair<T, T> > LineDDA(const T & x1, const T & y1, const T & x2, const T & y2)
+{
+       T dx = x2 - x1;
+       T dy = y2 - y1;
+       uint64_t steps = lround(max(abs(dx), abs(dy)));
+       T xInc = T(dx)/T(steps);
+       T yInc = T(dy)/T(steps);
+       T x = x1; T y = y1;
+       vector<pair<T,T> > result(steps);
+       for (uint64_t k = 0; k <= steps; ++k)
+       {
+               result[k] = pair<T,T>(round(x), round(y));
+               x += xInc;
+               y += yInc;
+       }
+       return result;
+}
+/**
+ * Only works for 0 < m < 1
+ */
+template <class T> vector<pair<T, T> > LineBresenham(const T & x1, const T & y1, const T & x2, const T & y2)
+{
+       T dx = abs(x2 - x1);
+       T dy = abs(y2 - y1);
+       T p = 2*dy - dx;
+       T two_dy = 2*dy;
+       T two_dxdy = 2*(dy-dx);
+
+       T x; T y; T xEnd;
+       if (x1 > x2)
+       {
+               x = x2;
+               y = y2;
+               xEnd = x1;
+       }
+       else
+       {
+               x = x1;
+               y = y1;
+               xEnd = x2;
+       }
+       vector<pair<T,T> > result;
+       while (x < xEnd)
+       {
+               x += 1;
+               if (p < 0)
+                       p += two_dy;
+               else
+               {
+                       y += 1;
+                       p += two_dxdy;
+               }
+               result.emplace_back(pair<T,T>(x,y));
+       }
+       return result;
+}
+
+int main(int argc, char ** argv)
+{
+       auto f = LineDDA<float>(0,0,400,200);
+       PointsToBitmap<float>(f, 1, 0,0,0,"lines.bmp");
+       auto i = LineBresenham<int>(0,100,400,300);
+       i.push_back(pair<int,int>(0,0));
+       PointsToBitmap<int>(i, 1, 255,0,0,"lines.bmp", true);
+}