From f1bf25b51f51a3a399414a9b56e006c7d66b1022 Mon Sep 17 00:00:00 2001
From: jaseg <git@jaseg.de>
Date: Fri, 4 Jun 2021 00:34:39 +0200
Subject: Fix transform math
---
svg-flatten/include/geom2d.hpp | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
(limited to 'svg-flatten/include')
diff --git a/svg-flatten/include/geom2d.hpp b/svg-flatten/include/geom2d.hpp
index b4cccf2..82dbfb5 100644
--- a/svg-flatten/include/geom2d.hpp
+++ b/svg-flatten/include/geom2d.hpp
@@ -21,6 +21,7 @@
#include <array>
#include <string>
#include <sstream>
+#include <iomanip>
#include <cmath>
#include <algorithm>
@@ -67,6 +68,7 @@ namespace gerbolyze {
return;
xx=a, yx=b, xy=c, yy=d, x0=e, y0=f;
+ cerr << "xform loaded " << dbg_str() << endl;
}
xform2d &translate(double x, double y) {
@@ -82,14 +84,14 @@ namespace gerbolyze {
}
xform2d &transform(const xform2d &other) {
- double n_xx = xx * other.xx + yx * other.xy;
- double n_yx = xx * other.yx + yx * other.yy;
+ double n_xx = other.xx * xx + other.yx * xy;
+ double n_yx = other.xx * yx + other.yx * yy;
- double n_xy = xy * other.xx + yy * other.xy;
- double n_yy = xy * other.yx + yy * other.yy;
+ double n_xy = other.xy * xx + other.yy * xy;
+ double n_yy = other.xy * yx + other.yy * yy;
- double n_x0 = x0 * other.xx + y0 * other.xy + other.x0;
- double n_y0 = x0 * other.yx + y0 * other.yy + other.y0;
+ double n_x0 = other.x0 * xx + other.y0 * xy + x0;
+ double n_y0 = other.x0 * yx + other.y0 * yy + y0;
xx = n_xx;
yx = n_yx;
@@ -152,6 +154,15 @@ namespace gerbolyze {
}
}
+ string dbg_str() {
+ ostringstream os;
+ os << "xform2d< " << setw(5);
+ os << xx << ", " << xy << ", " << x0 << " / ";
+ os << yy << ", " << yx << ", " << y0;
+ os << " >";
+ return os.str();
+ }
+
private:
double xx, yx,
xy, yy,
--
cgit