From: johanengelen <johanengelen@users.sourceforge.net>
Date: Mon, 23 Oct 2006 19:02:59 +0000 (+0000)
Subject: Axonometric grid: snapping to vertical gridlines
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=eee76dc9fd97872c225c448032e48d9c20611164;p=inkscape.git

Axonometric grid: snapping to vertical gridlines
---

diff --git a/src/Makefile_insert b/src/Makefile_insert
index fec782544..a6a827ead 100644
--- a/src/Makefile_insert
+++ b/src/Makefile_insert
@@ -40,6 +40,7 @@ libinkpre_a_SOURCES =	\
 	approx-equal.h remove-last.h	\
 	arc-context.cpp arc-context.h	\
 	attributes.cpp attributes.h	\
+	axonomgrid-snapper.cpp axonomgrid-snapper.h \
 	bad-uri-exception.h	\
 	brokenimage.xpm	\
 	color-rgba.h	\
diff --git a/src/axonomgrid-snapper.cpp b/src/axonomgrid-snapper.cpp
new file mode 100644
index 000000000..674357d44
--- /dev/null
+++ b/src/axonomgrid-snapper.cpp
@@ -0,0 +1,84 @@
+#ifdef AXONOM
+
+/**
+ *  \file axonomgrid-snapper.cpp
+ *  \brief Snapping things to axonometric grids.
+ *
+ * Author:
+ *   Johan Engelen <johan@shouraizou.nl>
+ *
+ * Copyright (C) 2006 Authors
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#include "sp-namedview.h"
+#include "inkscape.h"
+#include "desktop.h"
+#include "display/canvas-grid.h"
+
+/**
+ * \return x rounded to the nearest multiple of c1 plus c0.
+ *
+ * \note
+ * If c1==0 (and c0 is finite), then returns +/-inf.  This makes grid spacing of zero
+ * mean "ignore the grid in this dimention".  We're currently discussing "good" semantics
+ * for guide/grid snapping.
+ */
+
+/* FIXME: move this somewhere else, perhaps */
+static double round_to_nearest_multiple_plus(double x, double const c1, double const c0)
+{
+    return floor((x - c0) / c1 + .5) * c1 + c0;
+}
+
+Inkscape::AxonomGridSnapper::AxonomGridSnapper(SPNamedView const *nv, NR::Coord const d) : LineSnapper(nv, d)
+{
+
+}
+
+Inkscape::LineSnapper::LineList 
+Inkscape::AxonomGridSnapper::_getSnapLines(NR::Point const &p) const
+{
+    LineList s;
+
+    if ( NULL == _named_view ) {
+        return s;
+    }
+
+    SPCGrid *griditem = NULL;
+    for (GSList *l = _named_view->gridviews; l != NULL; l = l->next) {
+        // FIXME : this is a hack since there is only one view for now
+        //                 but when we'll handle multiple views, snapping should
+        //                 must be rethought and maybe only the current view
+        //                 should give back it's SHOWN lines to snap to
+        //                 For now, the last SPCGrid in _named_view->gridviews will be used.
+        griditem = SP_CGRID(l->data);
+    }
+
+    g_assert(griditem != NULL);
+
+    for (unsigned int i = 0; i < 2; ++i) {
+
+        /* This is to make sure we snap to only visible grid lines */
+        double scaled_spacing = griditem->sw[i]; // this is spacing of visible lines if screen pixels
+
+        // convert screen pixels to px
+        // FIXME: after we switch to snapping dist in screen pixels, this will be unnecessary
+        if (SP_ACTIVE_DESKTOP) {
+            scaled_spacing /= SP_ACTIVE_DESKTOP->current_zoom();
+        }
+
+        NR::Coord const rounded = round_to_nearest_multiple_plus(p[i],
+                                                                 scaled_spacing,
+                                                                 _named_view->gridorigin[i]);
+
+        s.push_back(std::make_pair(NR::Dim2(i), rounded));
+    }
+
+    return s;
+}
+
+
+
+#endif           
diff --git a/src/axonomgrid-snapper.h b/src/axonomgrid-snapper.h
new file mode 100644
index 000000000..46090ee56
--- /dev/null
+++ b/src/axonomgrid-snapper.h
@@ -0,0 +1,33 @@
+#ifndef SEEN_AXONOMGRID_SNAPPER_H
+#define SEEN_AXONOMGRID_SNAPPER_H
+
+/**
+ *  \file axonomgrid-snapper.h
+ *  \brief Snapping things to axonometricgrids.
+ *
+ * Author:
+ *   Johan Engelen <johan@shouraizou.nl>
+ *
+ * Copyright (C) 2006 Author
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#include "line-snapper.h"
+
+namespace Inkscape
+{
+
+class AxonomGridSnapper : public LineSnapper                             
+{                                                                       
+public:                                                                
+    AxonomGridSnapper(SPNamedView const *nv, NR::Coord const d);            
+
+private:    
+    LineList _getSnapLines(NR::Point const &p) const;
+};
+
+}
+
+#endif    
+