Index: vulkan-game.cpp =================================================================== --- vulkan-game.cpp (revision 1f81eccc69412a326f3861662b1688ee540440b2) +++ vulkan-game.cpp (revision 3950236c3448866af72c329d4983aa407e1d1646) @@ -779,4 +779,11 @@ } + if (leftLaserIdx != -1) { + updateLaserTarget(leftLaserIdx); + } + if (rightLaserIdx != -1) { + updateLaserTarget(rightLaserIdx); + } + for (SceneObject& asteroid : this->asteroidObjects) { if (!asteroid.ssbo.deleted) { @@ -1552,5 +1559,5 @@ {{-width / 2, 0.0f, 0.0f }, {0.0f, 0.0f }}, {{ width / 2, 0.0f, 0.0f }, {1.0f, 0.0f }}, - {{ width / 2, 0.0f, -length + width / 2}, {1.0f, 0.51f}}, + {{ width / 2, 0.0f, -length + width / 2}, {1.0f, 0.51f}}, {{-width / 2, 0.0f, -length + width / 2}, {0.0f, 0.51f}}, {{ width / 2, 0.0f, -length, }, {1.0f, 1.0f }}, @@ -1580,4 +1587,6 @@ float zAxisRotation = -atan2(glm::dot(glm::cross(normal, laserToCam), glm::normalize(ray)), glm::dot(normal, laserToCam)); + laser.targetAsteroid = nullptr; + laser.model_base = rotate(mat4(1.0f), zAxisRotation, vec3(0.0f, 0.0f, 1.0f)); @@ -1621,4 +1630,101 @@ laser.modified = true; +} + +void VulkanGame::updateLaserTarget(size_t index) { + SceneObject& laser = this->laserObjects[index]; + + // TODO: A lot of the values calculated here can be calculated once and saved when the laser is created, + // and then re-used here + + vec3 start = vec3(laser.model_transform * vec4(0.0f, 0.0f, 0.0f, 1.0f)); + vec3 end = vec3(laser.model_transform * vec4(0.0f, 0.0f, laser.vertices[6].pos.z, 1.0f)); + + vec3 intersection(0.0f), closestIntersection(0.0f); + SceneObject* closestAsteroid = nullptr; + unsigned int closestAsteroidIndex = -1; + + for (int i = 0; i < this->asteroidObjects.size(); i++) { + if (!this->asteroidObjects[i].ssbo.deleted && + this->getLaserAndAsteroidIntersection(this->asteroidObjects[i], start, end, intersection)) { + // TODO: Implement a more generic algorithm for testing the closest object by getting the distance between the points + // TODO: Also check which intersection is close to the start of the laser. This would make the algorithm work + // regardless of which way -Z is pointing + if (closestAsteroid == nullptr || intersection.z > closestIntersection.z) { + // TODO: At this point, find the real intersection of the laser with one of the asteroid's sides + closestAsteroid = &asteroidObjects[i]; + closestIntersection = intersection; + closestAsteroidIndex = i; + } + } + } + + float width = laser.vertices[0].pos.x - laser.vertices[1].pos.x; + + if (laser.targetAsteroid != closestAsteroid) { + laser.targetAsteroid = closestAsteroid; + } + + // Make the laser go past the end of the screen if it doesn't hit anything + float length = closestAsteroid == nullptr ? 5.24f : glm::length(closestIntersection - start); + + laser.vertices[4].pos.z = -length + width / 2; + laser.vertices[5].pos.z = -length + width / 2; + laser.vertices[6].pos.z = -length; + laser.vertices[7].pos.z = -length; + + // TODO: Consider if I want to set a flag and do this update in in updateScene() instead + updateObjectVertices(this->laserPipeline, laser, index); +} + +// TODO: Determine if I should pass start and end by reference or value since they don't get changed +// Probably use const reference +bool VulkanGame::getLaserAndAsteroidIntersection(SceneObject& asteroid, + vec3& start, vec3& end, vec3& intersection) { + /* + ### LINE EQUATIONS ### + x = x1 + u * (x2 - x1) + y = y1 + u * (y2 - y1) + z = z1 + u * (z2 - z1) + + ### SPHERE EQUATION ### + (x - x3)^2 + (y - y3)^2 + (z - z3)^2 = r^2 + + ### QUADRATIC EQUATION TO SOLVE ### + a*u^2 + b*u + c = 0 + WHERE THE CONSTANTS ARE + a = (x2 - x1)^2 + (y2 - y1)^2 + (z2 - z1)^2 + b = 2*( (x2 - x1)*(x1 - x3) + (y2 - y1)*(y1 - y3) + (z2 - z1)*(z1 - z3) ) + c = x3^2 + y3^2 + z3^2 + x1^2 + y1^2 + z1^2 - 2(x3*x1 + y3*y1 + z3*z1) - r^2 + + u = (-b +- sqrt(b^2 - 4*a*c)) / 2a + + If the value under the root is >= 0, we got an intersection + If the value > 0, there are two solutions. Take the one closer to 0, since that's the + one closer to the laser start point + */ + + vec3& center = asteroid.center; + + float a = pow(end.x - start.x, 2) + pow(end.y - start.y, 2) + pow(end.z - start.z, 2); + float b = 2 * ((start.x - end.x) * (start.x - center.x) + (end.y - start.y) * (start.y - center.y) + + (end.z - start.z) * (start.z - center.z)); + float c = pow(center.x, 2) + pow(center.y, 2) + pow(center.z, 2) + pow(start.x, 2) + pow(start.y, 2) + + pow(start.z, 2) - 2 * (center.x * start.x + center.y * start.y + center.z * start.z) - + pow(asteroid.radius, 2); + float discriminant = pow(b, 2) - 4 * a * c; + + if (discriminant >= 0.0f) { + // In this case, the negative root will always give the point closer to the laser start point + float u = (-b - sqrt(discriminant)) / (2 * a); + + // Check that the intersection is within the line segment corresponding to the laser + if (0.0f <= u && u <= 1.0f) { + intersection = start + u * (end - start); + return true; + } + } + + return false; } Index: vulkan-game.hpp =================================================================== --- vulkan-game.hpp (revision 1f81eccc69412a326f3861662b1688ee540440b2) +++ vulkan-game.hpp (revision 3950236c3448866af72c329d4983aa407e1d1646) @@ -96,4 +96,5 @@ vec3 center; // currently only matters for asteroids float radius; // currently only matters for asteroids + SceneObject* targetAsteroid; // currently only used for lasers }; @@ -271,4 +272,7 @@ void addLaser(vec3 start, vec3 end, vec3 color, float width); void translateLaser(size_t index, const vec3& translation); + void updateLaserTarget(size_t index); + bool getLaserAndAsteroidIntersection(SceneObject& asteroid, + vec3& start, vec3& end, vec3& intersection); // TODO: Since addObject() returns a reference to the new object now,