package box2dLight;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Mesh;
import com.badlogic.gdx.graphics.Mesh.VertexDataType;
import com.badlogic.gdx.graphics.VertexAttribute;
import com.badlogic.gdx.graphics.VertexAttributes.Usage;
import com.badlogic.gdx.math.MathUtils;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.physics.box2d.Body;
/**
* Abstract base class for all positional lights
*
* <p>Extends {@link Light}
*
* @author kalle_h
*/
public abstract class PositionalLight extends Light {
protected final Vector2 tmpEnd = new Vector2();
protected final Vector2 start = new Vector2();
protected Body body;
protected float bodyOffsetX;
protected float bodyOffsetY;
protected float bodyAngleOffset;
protected float sin[];
protected float cos[];
protected float endX[];
protected float endY[];
/**
* Creates new positional light and automatically adds it to the specified
* {@link RayHandler} instance.
*
* @param rayHandler
* not null instance of RayHandler
* @param rays
* number of rays - more rays make light to look more realistic
* but will decrease performance, can't be less than MIN_RAYS
* @param color
* light color
* @param distance
* light distance (if applicable)
* @param x
* horizontal position in world coordinates
* @param y
* vertical position in world coordinates
* @param directionDegree
* direction in degrees (if applicable)
*/
public PositionalLight(RayHandler rayHandler, int rays, Color color, float distance, float x, float y, float directionDegree) {
super(rayHandler, rays, color, distance, directionDegree);
start.x = x;
start.y = y;
lightMesh = new Mesh(VertexDataType.VertexArray, false, vertexNum, 0, new VertexAttribute(Usage.Position, 2,
"vertex_positions"), new VertexAttribute(Usage.ColorPacked, 4, "quad_colors"),
new VertexAttribute(Usage.Generic, 1, "s"));
softShadowMesh = new Mesh(VertexDataType.VertexArray, false, vertexNum * 2, 0, new VertexAttribute(Usage.Position, 2,
"vertex_positions"), new VertexAttribute(Usage.ColorPacked, 4, "quad_colors"),
new VertexAttribute(Usage.Generic, 1, "s"));
setMesh();
}
@Override
void update() {
updateBody();
if (cull()) return;
if (staticLight && !dirty) return;
dirty = false;
updateMesh();
}
@Override
void render() {
if (rayHandler.culling && culled) return;
rayHandler.lightRenderedLastFrame++;
lightMesh.render(
rayHandler.lightShader, GL20.GL_TRIANGLE_FAN, 0, vertexNum);
if (soft && !xray) {
softShadowMesh.render(
rayHandler.lightShader,
GL20.GL_TRIANGLE_STRIP,
0,
(vertexNum - 1) * 2);
}
}
@Override
public void attachToBody(Body body) {
attachToBody(body, 0f, 0f, 0f);
}
/**
* Attaches light to specified body with relative offset
*
* @param body
* that will be automatically followed, note that the body
* rotation angle is taken into account for the light offset
* and direction calculations
* @param offsetX
* horizontal relative offset in world coordinates
* @param offsetY
* vertical relative offset in world coordinates
*
*/
public void attachToBody(Body body, float offsetX, float offsetY) {
attachToBody(body, offsetX, offsetY, 0f);
}
/**
* Attaches light to specified body with relative offset and direction
*
* @param body
* that will be automatically followed, note that the body
* rotation angle is taken into account for the light offset
* and direction calculations
* @param offsetX
* horizontal relative offset in world coordinates
* @param offsetY
* vertical relative offset in world coordinates
* @param degrees
* directional relative offset in degrees
*/
public void attachToBody(Body body, float offsetX, float offSetY, float degrees) {
this.body = body;
bodyOffsetX = offsetX;
bodyOffsetY = offSetY;
bodyAngleOffset = degrees;
if (staticLight) dirty = true;
}
@Override
public Vector2 getPosition() {
tmpPosition.x = start.x;
tmpPosition.y = start.y;
return tmpPosition;
}
public Body getBody() {
return body;
}
/** @return horizontal starting position of light in world coordinates **/
@Override
public float getX() {
return start.x;
}
/** @return vertical starting position of light in world coordinates **/
@Override
public float getY() {
return start.y;
}
@Override
public void setPosition(float x, float y) {
start.x = x;
start.y = y;
if (staticLight) dirty = true;
}
@Override
public void setPosition(Vector2 position) {
start.x = position.x;
start.y = position.y;
if (staticLight) dirty = true;
}
@Override
public boolean contains(float x, float y) {
// fast fail
final float x_d = start.x - x;
final float y_d = start.y - y;
final float dst2 = x_d * x_d + y_d * y_d;
if (distance * distance <= dst2) return false;
// actual check
boolean oddNodes = false;
float x2 = mx[rayNum] = start.x;
float y2 = my[rayNum] = start.y;
float x1, y1;
for (int i = 0; i <= rayNum; x2 = x1, y2 = y1, ++i) {
x1 = mx[i];
y1 = my[i];
if (((y1 < y) && (y2 >= y)) || (y1 >= y) && (y2 < y)) {
if ((y - y1) / (y2 - y1) * (x2 - x1) < (x - x1)) oddNodes = !oddNodes;
}
}
return oddNodes;
}
@Override
protected void setRayNum(int rays) {
super.setRayNum(rays);
sin = new float[rays];
cos = new float[rays];
endX = new float[rays];
endY = new float[rays];
}
protected boolean cull() {
culled = rayHandler.culling && !rayHandler.intersect(
start.x, start.y, distance + softShadowLength);
return culled;
}
protected void updateBody() {
if (body == null || staticLight) return;
final Vector2 vec = body.getPosition();
float angle = body.getAngle();
final float cos = MathUtils.cos(angle);
final float sin = MathUtils.sin(angle);
final float dX = bodyOffsetX * cos - bodyOffsetY * sin;
final float dY = bodyOffsetX * sin + bodyOffsetY * cos;
start.x = vec.x + dX;
start.y = vec.y + dY;
setDirection(bodyAngleOffset + angle * MathUtils.radiansToDegrees);
}
protected void updateMesh() {
for (int i = 0; i < rayNum; i++) {
m_index = i;
f[i] = 1f;
tmpEnd.x = endX[i] + start.x;
mx[i] = tmpEnd.x;
tmpEnd.y = endY[i] + start.y;
my[i] = tmpEnd.y;
if (rayHandler.world != null && !xray) {
rayHandler.world.rayCast(ray, start, tmpEnd);
}
}
setMesh();
}
protected void setMesh() {
// ray starting point
int size = 0;
segments[size++] = start.x;
segments[size++] = start.y;
segments[size++] = colorF;
segments[size++] = 1;
// rays ending points.
for (int i = 0; i < rayNum; i++) {
segments[size++] = mx[i];
segments[size++] = my[i];
segments[size++] = colorF;
segments[size++] = 1 - f[i];
}
lightMesh.setVertices(segments, 0, size);
if (!soft || xray) return;
size = 0;
// rays ending points.
for (int i = 0; i < rayNum; i++) {
segments[size++] = mx[i];
segments[size++] = my[i];
segments[size++] = colorF;
final float s = (1 - f[i]);
segments[size++] = s;
segments[size++] = mx[i] + s * softShadowLength * cos[i];
segments[size++] = my[i] + s * softShadowLength * sin[i];
segments[size++] = zeroColorBits;
segments[size++] = 0f;
}
softShadowMesh.setVertices(segments, 0, size);
}
}