#include "perspectivesandboxview.h"
View::PointPtr
persp_p0,
persp_px,
persp_py,
persp_p1,
bounds_p0,
bounds_p1;
PerspectiveSandBoxView::PerspectiveSandBoxView():
persp_p0 (new View::Point( Vector2(-1, -1) )),
persp_px (new View::Point( Vector2( 1, -1) )),
persp_py (new View::Point( Vector2(-1, 1) )),
persp_p1 (new View::Point( Vector2( 1, 1) )),
bounds_p0 (new View::Point( Vector2(-2, -2) )),
bounds_p1 (new View::Point( Vector2( 2, 2) ))
{
transform.scale(50, 50);
points.push_back(persp_p0);
points.push_back(persp_px);
points.push_back(persp_py);
points.push_back(persp_p1);
points.push_back(bounds_p0);
points.push_back(bounds_p1);
}
void
PerspectiveSandBoxView::draw_grid(
const Cairo::RefPtr<Cairo::Context> &context,
const Matrix &matrix,
const Color &color )
{
const int count = 100;
const int subcount = 10;
const Real ps = get_pixel_size();
for(int i = -count; i < count; ++i) {
for(int j = -count; j < count; ++j) {
Vector4 src(i/(Real)subcount, j/(Real)subcount, 0, 1);
Vector4 dst = matrix*src;
Real w = dst.w;
if (w > real_precision) {
Vector2 pos(dst.x/w, dst.y/w);
Real ka = clamp(1/w, 0, 1);
Real a = color.a*ka;
Real r = 4*ps;
if (i) r *= 0.5;
if (j) r *= 0.5;
if (i % 10) r *= 0.75;
if (j % 10) r *= 0.75;
context->set_source_rgba(color.r, color.g, color.b, a);
context->arc(pos.x, pos.y, r, 0, 2.0*M_PI);
context->fill();
}
}
}
}
void
PerspectiveSandBoxView::draw_line(
const Cairo::RefPtr<Cairo::Context> &context,
const Pair2 &bounds,
Real a,
Real b,
Real c,
const Color &color )
{
}
void
PerspectiveSandBoxView::on_draw_view(const Cairo::RefPtr<Cairo::Context> &context) {
context->save();
const Real ps = get_pixel_size();
context->set_line_width(ps);
Vector2 p0 = persp_p0->position;
Vector2 px = persp_px->position;
Vector2 py = persp_py->position;
Vector2 p1 = persp_p1->position;
Pair2 bounds(bounds_p0->position, bounds_p1->position);
// perspective matrix
Matrix matrix;
{
Vector2 A = px - p1;
Vector2 B = py - p1;
Vector2 C = p0 + p1 - px - py;
Real cw = A.y*B.x - A.x*B.y;
Real aw = B.x*C.y - B.y*C.x;
Real bw = A.y*C.x - A.x*C.y;
Vector2 c = p0*cw;
Vector2 a = px*(cw + aw) - c;
Vector2 b = py*(cw + bw) - c;
matrix.row_x() = Vector4(a, 0, aw);
matrix.row_y() = Vector4(b, 0, bw);
matrix.row_w() = Vector4(c, 0, cw);
}
draw_grid(context, matrix, Color(0, 1, 0, 1));
// draw frames
context->set_source_rgba(0, 0, 1, 0.75);
context->move_to(p0.x, p0.y);
context->line_to(px.x, px.y);
context->line_to(p1.x, p1.y);
context->line_to(py.x, py.y);
context->close_path();
context->stroke();
context->move_to(bounds.p0.x, bounds.p0.y);
context->line_to(bounds.p1.x, bounds.p0.y);
context->line_to(bounds.p1.x, bounds.p1.y);
context->line_to(bounds.p0.x, bounds.p1.y);
context->close_path();
context->stroke();
context->restore();
}