Java tutorial
/* * * The MIT License (MIT) * * Copyright (c) <2015> <Andreas Modahl> * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. * */ package org.ams.testapps.prettypaint; import com.badlogic.gdx.ApplicationAdapter; import com.badlogic.gdx.Gdx; import com.badlogic.gdx.InputProcessor; import com.badlogic.gdx.graphics.Color; import com.badlogic.gdx.graphics.GL20; import com.badlogic.gdx.graphics.OrthographicCamera; import com.badlogic.gdx.graphics.Texture; import com.badlogic.gdx.graphics.g2d.TextureRegion; import com.badlogic.gdx.math.MathUtils; import com.badlogic.gdx.math.Vector2; import com.badlogic.gdx.utils.Array; import org.ams.prettypaint.OutlinePolygon; import org.ams.prettypaint.PrettyPolygonBatch; import org.ams.prettypaint.TexturePolygon; /** * This demo shows a spinning circle and a background. */ public class CircleAndBackground extends ApplicationAdapter implements InputProcessor { // It is best to use a OrthographicCamera with PrettyPaint OrthographicCamera camera; // some variables used for controlling the camera Vector2 lastWorldTouchDown; Vector2 cameraPositionAtLastWorldTouch; PrettyPolygonBatch batch; TexturePolygon background; Texture texture; OutlinePolygon shadowPolygon; OutlinePolygon outlinePolygon; float arcAccumulator = 0; float rotationAccumulator = 0; Array<Vector2> circleVertices = new Array<Vector2>(); @Override public void dispose() { if (batch != null) batch.dispose(); if (texture != null) texture.dispose(); } @Override public void create() { Gdx.gl.glBlendFunc(GL20.GL_SRC_ALPHA, GL20.GL_ONE_MINUS_SRC_ALPHA); Gdx.input.setInputProcessor(this); float w = Gdx.graphics.getWidth() * 0.5f; float h = Gdx.graphics.getHeight() * 0.5f; camera = new OrthographicCamera(10, 10 * (h / w)); batch = new PrettyPolygonBatch(); // create the vertices used for the circle float radius = 2f; Vector2 v = new Vector2(radius, 0); float angle = MathUtils.PI2 / 300; for (float rad = 0; rad <= MathUtils.PI2; rad += angle) { v.rotateRad(angle); circleVertices.add(new Vector2(v)); } // prepare circle outlinePolygon = new OutlinePolygon(); outlinePolygon.setColor(Color.BLACK); outlinePolygon.setClosedPolygon(false); // prepare shadow around circle shadowPolygon = new OutlinePolygon(); shadowPolygon.setColor(new Color(0, 0, 0, 0.4f)); shadowPolygon.setHalfWidth(outlinePolygon.getHalfWidth() * 3); shadowPolygon.setClosedPolygon(false); // prepare the vertices for background and frame float hw = camera.viewportWidth * 0.5f; float hh = camera.viewportHeight * 0.5f; Array<Vector2> cameraBounds = new Array<Vector2>(); cameraBounds.add(new Vector2(-hw, -hh)); cameraBounds.add(new Vector2(hw, -hh)); cameraBounds.add(new Vector2(hw, hh)); cameraBounds.add(new Vector2(-hw, hh)); // prepare background texture = new Texture("images/for packing/backgrounds-dark/escheresque_ste.png"); texture.setFilter(Texture.TextureFilter.Linear, Texture.TextureFilter.Linear); background = new TexturePolygon(); background.setTextureRegion(new TextureRegion(texture)); background.setScale(0.96f); background.setVertices(cameraBounds); } @Override public void render() { float delta = Gdx.graphics.getDeltaTime(); // swing the length of the arc arcAccumulator += delta; float sin = MathUtils.sin(arcAccumulator % MathUtils.PI); int n = (int) (circleVertices.size * sin * 0.5f); while (outlinePolygon.getVertexCount() > n) { outlinePolygon.removeVertex(outlinePolygon.getVertexCount() - 1); shadowPolygon.removeVertex(shadowPolygon.getVertexCount() - 1); } while (outlinePolygon.getVertexCount() < n) { Vector2 vertex = circleVertices.get(outlinePolygon.getVertexCount() % circleVertices.size); outlinePolygon.addVertex(vertex); shadowPolygon.addVertex(vertex); } // rotate the whole thing sin = MathUtils.sin((arcAccumulator + MathUtils.PI * 0.5f) % MathUtils.PI); rotationAccumulator += 1 * sin * delta; outlinePolygon.setAngle(rotationAccumulator * MathUtils.PI2); shadowPolygon.setAngle(rotationAccumulator * MathUtils.PI2); // draw Gdx.gl20.glClearColor(1, 1, 1, 1); Gdx.gl20.glClear(GL20.GL_COLOR_BUFFER_BIT); batch.begin(camera); background.draw(batch); shadowPolygon.draw(batch); outlinePolygon.draw(batch); batch.end(); } private void updateBackgroundPositionAndZoom() { float x = camera.position.x; float y = camera.position.y; background.setPosition(x, y); background.setTextureTranslation(x * 0.1f, y * 0.1f); float scale = camera.zoom; background.setScale(scale); } @Override public void resize(int width, int height) { camera.setToOrtho(false, 10, 10 * ((float) height / (float) width)); camera.position.x = 0; camera.position.y = 0; camera.update(); // update the vertices for background float hw = camera.viewportWidth * 0.5f; float hh = camera.viewportHeight * 0.5f; Array<Vector2> cameraBounds = new Array<Vector2>(); cameraBounds.add(new Vector2(-hw, -hh)); cameraBounds.add(new Vector2(hw, -hh)); cameraBounds.add(new Vector2(hw, hh)); cameraBounds.add(new Vector2(-hw, hh)); background.setVertices(cameraBounds); updateBackgroundPositionAndZoom(); } @Override public boolean touchDragged(int screenX, int screenY, int pointer) { if (cameraPositionAtLastWorldTouch == null) return false; if (lastWorldTouchDown == null) return false; Vector2 worldTouchDrag = getPositionOfTouch(screenX, screenY); Vector2 pos = new Vector2(cameraPositionAtLastWorldTouch).sub(worldTouchDrag).add(lastWorldTouchDown); camera.position.set(pos.x, pos.y, camera.position.z); camera.update(); updateBackgroundPositionAndZoom(); return true; } @Override public boolean scrolled(int amount) { setZoom(camera.zoom * (1 + amount * 0.1f), Gdx.input.getX(), Gdx.input.getY()); updateBackgroundPositionAndZoom(); return true; } @Override public boolean keyDown(int keycode) { return false; } @Override public boolean keyUp(int keycode) { return false; } @Override public boolean keyTyped(char character) { return false; } @Override public boolean touchDown(int screenX, int screenY, int pointer, int button) { lastWorldTouchDown = getPositionOfTouch(screenX, screenY); cameraPositionAtLastWorldTouch = new Vector2(camera.position.x, camera.position.y); return true; } @Override public boolean touchUp(int screenX, int screenY, int pointer, int button) { return false; } /** * @param zoom the cameras zoom will be set to this value. * @param screenX the screen x-coordinate you want to zoom in on(or away from). * @param screenY the screen y-coordinate you want to zoom in on(or away from). */ public void setZoom(float zoom, int screenX, int screenY) { Vector2 touchWorldBefore = getPositionOfTouch(screenX, screenY); touchWorldBefore.add(camera.position.x, camera.position.y); camera.zoom = zoom; camera.update(); Vector2 touchWorldAfter = getPositionOfTouch(screenX, screenY); touchWorldAfter.add(camera.position.x, camera.position.y); camera.translate(touchWorldBefore.sub(touchWorldAfter)); camera.update(); } /** * @param screenX pixel. * @param screenY pixel. * @return position of touch in "world units", with center of screen as origin. */ public Vector2 getPositionOfTouch(int screenX, int screenY) { float halfWidth = Gdx.graphics.getWidth() * 0.5f; float halfHeight = Gdx.graphics.getHeight() * 0.5f; Vector2 pos = new Vector2(screenX - halfWidth, halfHeight - screenY); pos.scl(1f / halfWidth, 1f / halfHeight); pos.scl(camera.zoom); // convert to world units relative to center of screen pos.scl(camera.viewportWidth * 0.5f, camera.viewportHeight * 0.5f); return pos; } @Override public boolean mouseMoved(int screenX, int screenY) { return false; } }