void Color::lerp(const Color& c1, const Color& c2, float t)
{
color_lerp(&c_, &c1.c_, &c2.c_, t);
}
// returns true if further calls could possibly result in a mesh
void LightCaster::add_triangle(Mesh* result, const Vector_& light,
Wall* last_closest, float beginAngle, float nextAngle) {
// within our angle bounds?
float da1 = signed_angular_distance(angle, beginAngle);
if(da1 > halfwidth) return; // swath begins after our cutoff
float da2 = signed_angular_distance(angle, nextAngle);
if(da2 < -halfwidth) return; // swath ends before our cutoff
// clamp the values we did get
float ada1 = ABS(da1);
if(ada1 > halfwidth) {
float fixup = halfwidth - ada1;
beginAngle += fixup * sign(da1);
}
float ada2 = ABS(da2);
if(ada2 > halfwidth) {
float fixup = halfwidth - ada2;
nextAngle += fixup * sign(da2);
}
int steps = ceilf(signed_angular_distance(beginAngle, nextAngle) / max_angle_step);
float oldBegin = beginAngle;
float oldNext = nextAngle;
for(int ii = 0; ii < steps; ++ii) {
beginAngle = oldBegin + ii * max_angle_step;
float delta = signed_angular_distance(beginAngle, oldNext);
nextAngle = beginAngle + MIN(delta, max_angle_step);
// interset the discovered angle range with the previously
// closest wall segment
Vector_ a1;
a1.x = light.x + cosf(beginAngle);
a1.y = light.y + sinf(beginAngle);
Vector_ a2;
a2.x = light.x + cosf(nextAngle);
a2.y = light.y + sinf(nextAngle);
Vector_ i1, i2;
line_intersection(&i1, &last_closest->start, &last_closest->end, &light, &a1);
line_intersection(&i2, &last_closest->start, &last_closest->end, &light, &a2);
Color c1, c2;
float d1 = vector_dist(&i1, &light);
float d2 = vector_dist(&i2, &light);
color_lerp(&c1, &min_color, &max_color, MIN(1.0f, d1 / max_range));
color_lerp(&c2, &min_color, &max_color, MIN(1.0f, d2 / max_range));
if(d1 > max_range) {
vector_direction_scaled(&i1, &i1, &light, max_range);
vector_add(&i1, &i1, &light);
}
if(d2 > max_range) {
vector_direction_scaled(&i2, &i2, &light, max_range);
vector_add(&i2, &i2, &light);
}
// add a triangle to the mesh
result->add_point(light, min_color);
result->add_point(i1, c1);
result->add_point(i2, c2);
}
}