1 files changed, 153 insertions, 0 deletions
diff --git a/src/3rdparty/2geom/src/toys/box3d.cpp b/src/3rdparty/2geom/src/toys/box3d.cpp
new file mode 100644
index 0000000..06d2e6a
--- /dev/null
+++ b/src/3rdparty/2geom/src/toys/box3d.cpp
@@ -0,0 +1,153 @@
+#include <toys/toy-framework-2.h>
+
+#include <vector>
+using std::vector;
+using namespace Geom;
+using namespace std;
+
+class Box3d: public Toy {
+    Point orig;
+    
+    double tmat[3][4];
+    double c[8][4];
+    Point corners[8];
+
+    PointHandle origin_handle;
+    PointSetHandle vanishing_points_handles, axes_handles;
+    
+    void draw(cairo_t *cr, std::ostringstream *notify, int width, int height, bool save, std::ostringstream *timer_stream) override {
+        Geom::Point dir(1,-2);
+
+	cairo_set_source_rgba (cr, 0., 0.125, 0, 1);
+
+        // draw vertical lines for the VP sliders and keep the sliders at their horizontal positions
+        draw_slider_lines (cr);
+        axes_handles.pts[0][0] = 30;
+        axes_handles.pts[1][0] = 45;
+        axes_handles.pts[2][0] = 60;
+
+        /* create the transformation matrix for the map  P^3 --> P^2 that has the following effect:
+           (1 : 0 : 0 : 0) --> vanishing point in x direction (= handle #0)
+           (0 : 1 : 0 : 0) --> vanishing point in y direction (= handle #1)
+           (0 : 0 : 1 : 0) --> vanishing point in z direction (= handle #2)
+           (0 : 0 : 0 : 1) --> origin (= handle #3)
+        */
+        for (int j = 0; j < 4; ++j) {
+            tmat[0][j] = vanishing_points_handles.pts[j][0];
+            tmat[1][j] = vanishing_points_handles.pts[j][1];
+            tmat[2][j] = 1;
+        }
+
+        *notify << "Projection matrix:" << endl;
+        for (auto & i : tmat) {
+            for (double j : i) {
+                *notify << j << " ";
+            }
+            *notify << endl;
+        }
+
+        // draw the projective images of the box's corners
+        for (int i = 0; i < 8; ++i) {
+            corners[i] = proj_image (cr, c[i]);
+        }
+        draw_box(cr, corners);
+        cairo_set_line_width (cr, 2);
+	cairo_stroke(cr);
+
+        Toy::draw(cr, notify, width, height, save,timer_stream);
+    }
+    void first_time(int /*argc*/, char** /*argv*/) override {
+        // Finite images of the three vanishing points and the origin
+        handles.push_back(&origin_handle);
+        handles.push_back(&vanishing_points_handles);
+        handles.push_back(&axes_handles);
+        vanishing_points_handles.push_back(550,350);
+        vanishing_points_handles.push_back(150,300);
+        vanishing_points_handles.push_back(380,40);
+        vanishing_points_handles.push_back(340,450);
+        // plane origin
+        origin_handle.pos = Point(180,65);
+
+        // Handles for moving in axes directions
+        axes_handles.push_back(30,300);
+        axes_handles.push_back(45,300);
+        axes_handles.push_back(60,300);
+        
+        // Box corners
+        for (int i = 0; i < 8; ++i) {
+            c[i][0] = ((i & 1) ? 1 : 0);
+            c[i][1] = ((i & 2) ? 1 : 0);
+            c[i][2] = ((i & 4) ? 1 : 0);
+            c[i][3] = 1;
+        }
+
+        orig = origin_handle.pos;
+    }
+    Geom::Point proj_image (cairo_t *cr, const double pt[4]) {
+        double res[3];
+        for (int j = 0; j < 3; ++j) {
+            res[j] =
+                tmat[j][0] * (pt[0] - (axes_handles.pts[0][1]-300)/100)
+                + tmat[j][1] * (pt[1] - (axes_handles.pts[1][1]-300)/100)
+                + tmat[j][2] * (pt[2] - (axes_handles.pts[2][1]-300)/100)
+                + tmat[j][3] * pt[3];
+        }
+        if (fabs (res[2]) > 0.000001) {
+            Geom::Point result = Geom::Point (res[0]/res[2], res[1]/res[2]);
+            draw_handle(cr, result);
+            return result;
+        }
+        assert(0); // unclipped point
+        return Geom::Point(0,0);
+    }
+    
+    void draw_box (cairo_t *cr, Geom::Point corners[8]) {
+        cairo_move_to(cr,corners[0]);
+        cairo_line_to(cr,corners[1]);
+        cairo_line_to(cr,corners[3]);
+        cairo_line_to(cr,corners[2]);
+        cairo_close_path(cr);
+
+        cairo_move_to(cr,corners[4]);
+        cairo_line_to(cr,corners[5]);
+        cairo_line_to(cr,corners[7]);
+        cairo_line_to(cr,corners[6]);
+        cairo_close_path(cr);
+
+        for(int i = 0 ; i < 4; i++) {
+            cairo_move_to(cr,corners[i]);
+            cairo_line_to(cr,corners[i+4]);
+        }
+    }
+
+    void draw_slider_lines (cairo_t *cr) {
+        cairo_move_to(cr, Geom::Point(20,300));
+        cairo_line_to(cr, Geom::Point(70,300));
+    
+        for(int i = 0; i < 3; i++) {
+            cairo_move_to(cr, Geom::Point(30 + 15*i,00));
+            cairo_line_to(cr, Geom::Point(30 + 15*i,450));
+        }
+        
+        cairo_set_line_width (cr, 1);
+        cairo_set_source_rgba (cr, 0.2, 0.2, 0.2, 1);
+        cairo_stroke(cr);
+    }
+};
+
+int main(int argc, char **argv) {
+    init(argc, argv, new Box3d);
+    return 0;
+}
+
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :