Java tutorial
/******************************************************************************* * Copyright 2011 See AUTHORS file. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. ******************************************************************************/ package com.badlogic.gdx.graphics.g2d; import com.badlogic.gdx.graphics.Texture; /** Defines a rectangular area of a texture. The coordinate system used has its origin in the upper left corner with the x-axis * pointing to the right and the y axis pointing downwards. * @author mzechner * @author Nathan Sweet */ public class TextureRegion { Texture texture; float u, v; float u2, v2; int regionWidth, regionHeight; /** Constructs a region with no texture and no coordinates defined. */ public TextureRegion() { } /** Constructs a region the size of the specified texture. */ public TextureRegion(Texture texture) { if (texture == null) throw new IllegalArgumentException("texture cannot be null."); this.texture = texture; setRegion(0, 0, texture.getWidth(), texture.getHeight()); } /** @param width The width of the texture region. May be negative to flip the sprite when drawn. * @param height The height of the texture region. May be negative to flip the sprite when drawn. */ public TextureRegion(Texture texture, int width, int height) { this.texture = texture; setRegion(0, 0, width, height); } /** @param width The width of the texture region. May be negative to flip the sprite when drawn. * @param height The height of the texture region. May be negative to flip the sprite when drawn. */ public TextureRegion(Texture texture, int x, int y, int width, int height) { this.texture = texture; setRegion(x, y, width, height); } public TextureRegion(Texture texture, float u, float v, float u2, float v2) { this.texture = texture; setRegion(u, v, u2, v2); } /** Constructs a region with the same texture and coordinates of the specified region. */ public TextureRegion(TextureRegion region) { setRegion(region); } /** Constructs a region with the same texture as the specified region and sets the coordinates relative to the specified region. * @param width The width of the texture region. May be negative to flip the sprite when drawn. * @param height The height of the texture region. May be negative to flip the sprite when drawn. */ public TextureRegion(TextureRegion region, int x, int y, int width, int height) { setRegion(region, x, y, width, height); } /** Sets the texture and sets the coordinates to the size of the specified texture. */ public void setRegion(Texture texture) { this.texture = texture; setRegion(0, 0, texture.getWidth(), texture.getHeight()); } /** @param width The width of the texture region. May be negative to flip the sprite when drawn. * @param height The height of the texture region. May be negative to flip the sprite when drawn. */ public void setRegion(int x, int y, int width, int height) { float invTexWidth = 1f / texture.getWidth(); float invTexHeight = 1f / texture.getHeight(); setRegion(x * invTexWidth, y * invTexHeight, (x + width) * invTexWidth, (y + height) * invTexHeight); regionWidth = Math.abs(width); regionHeight = Math.abs(height); } public void setRegion(float u, float v, float u2, float v2) { int texWidth = texture.getWidth(), texHeight = texture.getHeight(); regionWidth = Math.round(Math.abs(u2 - u) * texWidth); regionHeight = Math.round(Math.abs(v2 - v) * texHeight); // For a 1x1 region, adjust UVs toward pixel center to avoid filtering artifacts on AMD GPUs when drawing very stretched. if (regionWidth == 1 && regionHeight == 1) { float adjustX = 0.25f / texWidth; u += adjustX; u2 -= adjustX; float adjustY = 0.25f / texHeight; v += adjustY; v2 -= adjustY; } this.u = u; this.v = v; this.u2 = u2; this.v2 = v2; } /** Sets the texture and coordinates to the specified region. */ public void setRegion(TextureRegion region) { texture = region.texture; setRegion(region.u, region.v, region.u2, region.v2); } /** Sets the texture to that of the specified region and sets the coordinates relative to the specified region. */ public void setRegion(TextureRegion region, int x, int y, int width, int height) { texture = region.texture; setRegion(region.getRegionX() + x, region.getRegionY() + y, width, height); } public Texture getTexture() { return texture; } public void setTexture(Texture texture) { this.texture = texture; } public float getU() { return u; } public void setU(float u) { this.u = u; regionWidth = Math.round(Math.abs(u2 - u) * texture.getWidth()); } public float getV() { return v; } public void setV(float v) { this.v = v; regionHeight = Math.round(Math.abs(v2 - v) * texture.getHeight()); } public float getU2() { return u2; } public void setU2(float u2) { this.u2 = u2; regionWidth = Math.round(Math.abs(u2 - u) * texture.getWidth()); } public float getV2() { return v2; } public void setV2(float v2) { this.v2 = v2; regionHeight = Math.round(Math.abs(v2 - v) * texture.getHeight()); } public int getRegionX() { return Math.round(u * texture.getWidth()); } public void setRegionX(int x) { setU(x / (float) texture.getWidth()); } public int getRegionY() { return Math.round(v * texture.getHeight()); } public void setRegionY(int y) { setV(y / (float) texture.getHeight()); } /** Returns the region's width. */ public int getRegionWidth() { return regionWidth; } public void setRegionWidth(int width) { if (isFlipX()) { setU(u2 + width / (float) texture.getWidth()); } else { setU2(u + width / (float) texture.getWidth()); } } /** Returns the region's height. */ public int getRegionHeight() { return regionHeight; } public void setRegionHeight(int height) { if (isFlipY()) { setV(v2 + height / (float) texture.getHeight()); } else { setV2(v + height / (float) texture.getHeight()); } } public void flip(boolean x, boolean y) { if (x) { float temp = u; u = u2; u2 = temp; } if (y) { float temp = v; v = v2; v2 = temp; } } public boolean isFlipX() { return u > u2; } public boolean isFlipY() { return v > v2; } /** Offsets the region relative to the current region. Generally the region's size should be the entire size of the texture in * the direction(s) it is scrolled. * @param xAmount The percentage to offset horizontally. * @param yAmount The percentage to offset vertically. This is done in texture space, so up is negative. */ public void scroll(float xAmount, float yAmount) { if (xAmount != 0) { float width = (u2 - u) * texture.getWidth(); u = (u + xAmount) % 1; u2 = u + width / texture.getWidth(); } if (yAmount != 0) { float height = (v2 - v) * texture.getHeight(); v = (v + yAmount) % 1; v2 = v + height / texture.getHeight(); } } /** Helper function to create tiles out of this TextureRegion starting from the top left corner going to the right and ending at * the bottom right corner. Only complete tiles will be returned so if the region's width or height are not a multiple of the * tile width and height not all of the region will be used. This will not work on texture regions returned form a TextureAtlas * that either have whitespace removed or where flipped before the region is split. * * @param tileWidth a tile's width in pixels * @param tileHeight a tile's height in pixels * @return a 2D array of TextureRegions indexed by [row][column]. */ public TextureRegion[][] split(int tileWidth, int tileHeight) { int x = getRegionX(); int y = getRegionY(); int width = regionWidth; int height = regionHeight; int rows = height / tileHeight; int cols = width / tileWidth; int startX = x; TextureRegion[][] tiles = new TextureRegion[rows][cols]; for (int row = 0; row < rows; row++, y += tileHeight) { x = startX; for (int col = 0; col < cols; col++, x += tileWidth) { tiles[row][col] = new TextureRegion(texture, x, y, tileWidth, tileHeight); } } return tiles; } /** Helper function to create tiles out of the given {@link Texture} starting from the top left corner going to the right and * ending at the bottom right corner. Only complete tiles will be returned so if the texture's width or height are not a * multiple of the tile width and height not all of the texture will be used. * * @param texture the Texture * @param tileWidth a tile's width in pixels * @param tileHeight a tile's height in pixels * @return a 2D array of TextureRegions indexed by [row][column]. */ public static TextureRegion[][] split(Texture texture, int tileWidth, int tileHeight) { TextureRegion region = new TextureRegion(texture); return region.split(tileWidth, tileHeight); } }