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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-13 11:57:42 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-13 11:57:42 +0000
commit61f3ab8f23f4c924d455757bf3e65f8487521b5a (patch)
tree885599a36a308f422af98616bc733a0494fe149a /src/toys/box3d.cpp
parentInitial commit. (diff)
downloadlib2geom-61f3ab8f23f4c924d455757bf3e65f8487521b5a.tar.xz
lib2geom-61f3ab8f23f4c924d455757bf3e65f8487521b5a.zip
Adding upstream version 1.3.upstream/1.3upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/toys/box3d.cpp')
-rw-r--r--src/toys/box3d.cpp153
1 files changed, 153 insertions, 0 deletions
diff --git a/src/toys/box3d.cpp b/src/toys/box3d.cpp
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+++ b/src/toys/box3d.cpp
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+#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 :