Class: Cosmos::LineClip

Inherits:

Object

• Object
• Cosmos::LineClip

Defined in:

ext/cosmos/ext/line_graph/line_graph.c

Class Method Summary

• .line_clip(x0, y0, x1, y1, xmin, ymin, xmax, ymax) ⇒ Object

  This is a line-clipping algorithm.

Class Method Details

.line_clip(x0, y0, x1, y1, xmin, ymin, xmax, ymax) ⇒ Object

This is a line-clipping algorithm. It takes two points and a viewable area. It returns the part of the line that is within the viewable area. If no part of the line is viewable, it returns nil

# File 'ext/cosmos/ext/line_graph/line_graph.c', line 176

static VALUE line_clip(VALUE self, VALUE x0, VALUE y0, VALUE x1, VALUE y1, VALUE xmin, VALUE ymin, VALUE xmax, VALUE ymax) {
  volatile VALUE result = Qnil;
  volatile VALUE result_clipped0 = Qnil;
  volatile VALUE result_clipped1 = Qnil;
  volatile VALUE return_value = Qnil;
  double double_x0 = 0.0;
  double double_y0 = 0.0;
  double double_x1 = 0.0;
  double double_y1 = 0.0;
  double double_xmin = 0.0;
  double double_ymin = 0.0;
  double double_xmax = 0.0;
  double double_ymax = 0.0;
  double result_x0 = 0.0;
  double result_y0 = 0.0;
  double result_x1 = 0.0;
  double result_y1 = 0.0;

  double_x0 = RFLOAT_VALUE(rb_funcall(x0, id_method_to_f, 0));
  double_y0 = RFLOAT_VALUE(rb_funcall(y0, id_method_to_f, 0));
  double_x1 = RFLOAT_VALUE(rb_funcall(x1, id_method_to_f, 0));
  double_y1 = RFLOAT_VALUE(rb_funcall(y1, id_method_to_f, 0));
  double_xmin = RFLOAT_VALUE(rb_funcall(xmin, id_method_to_f, 0));
  double_ymin = RFLOAT_VALUE(rb_funcall(ymin, id_method_to_f, 0));
  double_xmax = RFLOAT_VALUE(rb_funcall(xmax, id_method_to_f, 0));
  double_ymax = RFLOAT_VALUE(rb_funcall(ymax, id_method_to_f, 0));

  result = line_clip_internal(double_x0, double_y0, double_x1, double_y1, double_xmin, double_ymin, double_xmax, double_ymax, &result_x0, &result_y0, &result_x1, &result_y1, &result_clipped0, &result_clipped1);

  if (result == Qtrue)
  {
    return_value = rb_ary_new2(6);
    rb_ary_push(return_value, rb_float_new(result_x0));
    rb_ary_push(return_value, rb_float_new(result_y0));
    rb_ary_push(return_value, rb_float_new(result_x1));
    rb_ary_push(return_value, rb_float_new(result_y1));
    rb_ary_push(return_value, result_clipped0);
    rb_ary_push(return_value, result_clipped1);
  }

  return return_value;
}