renderBall.cpp

#include "utils/renderBall.h"
#include "utils/bridge.h"

#include <array>
#include <iostream>


constexpr float M_PI = 3.14159265358979323846;

void renderCircle(RLURenderer& renderer, const vec3& center, float radius, const vec3& axis, const size_t numPoints, rlbot::Color color) {
	std::vector<vec3> points{ numPoints + 1 };
	float angle = 0;
	const vec3 orth1 = normalize(vec3{ 0, -axis[2], axis[1] });
	const vec3 orth2 = normalize(cross(axis, orth1));
	for (int i = 0; i < numPoints; i++) {
		angle += 2 * M_PI / numPoints;
		points[i] = center + radius * (cosf(angle) * orth1 + sinf(angle) * orth2);
	}
	points.back() = points.front();
	renderer.DrawPolyLine3D(color, points);
}


void renderBall(RLURenderer& renderer, const RLBotBM::Ball& ball, rlbot::Color color) {
	auto center = vec3ToRLU(ball.position);
	constexpr int stepsPerAxis = 4;
	const std::array axes { vec3{ 1, 0, 0 }, vec3{ 0, 1, 0 }, vec3{ 0, 0, 1 } };
	const auto ballRotator = quatToRLU(ball.orientation);
	int totalPoints = 0;
	int totalPolyLines = 0;
	for (const auto& axis : axes) {
		auto localAxis = dot(ballRotator, axis);
		// renderer.DrawLine3D(rlbot::Color::green, center - ball.radius * localAxis, center + ball.radius * localAxis);
		for (float t = -1.f + 1.f / stepsPerAxis; t < 1.f; t += 2.f / stepsPerAxis) {
			vec3 circleCenter = center + ball.radius * t * localAxis;
			float relSize = sqrtf(1 - t * t);
			int numPoints = 6 + 6 * sqrtf(1 - t * t);
			renderCircle(renderer, circleCenter, ball.radius * relSize, localAxis, numPoints, color);
			totalPolyLines++;
			totalPoints += numPoints + 1;
		}
	}
	// std::cout << "Total polylines: " << totalPolyLines << " Total points: " << totalPoints << std::endl;
}