1 /* 2 * Copyright (C) 2023 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.android.wallpaper.weathereffects.graphics.snow 18 19 import android.content.Context 20 import android.graphics.Bitmap 21 import android.graphics.RuntimeShader 22 import androidx.annotation.FloatRange 23 import com.google.android.wallpaper.weathereffects.graphics.utils.GraphicsUtils 24 25 /** Configuration for a snow effect. */ 26 data class SnowEffectConfig( 27 /** The main shader of the effect. */ 28 val shader: RuntimeShader, 29 /** The shader of accumulated snow effect. */ 30 val accumulatedSnowShader: RuntimeShader, 31 /** The color grading shader. */ 32 val colorGradingShader: RuntimeShader, 33 /** 34 * The noise texture, which will be used to add fluffiness to the snow flakes. The texture is 35 * expected to be tileable, and at least 16-bit per channel for render quality. 36 */ 37 val noiseTexture: Bitmap, 38 /** The main lut (color grading) for the effect. */ 39 val lut: Bitmap?, 40 /** A bitmap containing the foreground of the image. */ 41 val foreground: Bitmap, 42 /** A bitmap containing the background of the image. */ 43 val background: Bitmap, 44 /** The amount of the snow flakes. This contributes to the color grading as well. */ 45 @FloatRange(from = 0.0, to = 1.0) val intensity: Float, 46 /** The intensity of the color grading. 0: no color grading, 1: color grading in full effect. */ 47 @FloatRange(from = 0.0, to = 1.0) val colorGradingIntensity: Float, 48 /** Max thickness for the accumulated snow. */ 49 val maxAccumulatedSnowThickness: Float, 50 ) { 51 /** 52 * Constructor for [SnowEffectConfig]. 53 * 54 * @param context the application context. 55 * @param foreground a bitmap containing the foreground of the image. 56 * @param background a bitmap containing the background of the image. 57 * @param intensity initial intensity that affects the amount of snow flakes and color grading. 58 * Expected range is [0, 1]. You can always change the intensity dynamically. Defaults to 1. 59 */ 60 constructor( 61 context: Context, 62 foreground: Bitmap, 63 background: Bitmap, 64 intensity: Float = DEFAULT_INTENSITY, 65 ) : this( 66 shader = GraphicsUtils.loadShader(context.assets, SHADER_PATH), 67 accumulatedSnowShader = 68 GraphicsUtils.loadShader(context.assets, ACCUMULATED_SNOW_SHADER_PATH), 69 colorGradingShader = GraphicsUtils.loadShader(context.assets, COLOR_GRADING_SHADER_PATH), 70 noiseTexture = GraphicsUtils.loadTexture(context.assets, NOISE_TEXTURE_PATH) 71 ?: throw RuntimeException("Noise texture is missing."), 72 lut = GraphicsUtils.loadTexture(context.assets, LOOKUP_TABLE_TEXTURE_PATH), 73 foreground, 74 background, 75 intensity, 76 COLOR_GRADING_INTENSITY, 77 MAX_SNOW_THICKNESS 78 ) 79 80 private companion object { 81 private const val SHADER_PATH = "shaders/snow_effect.agsl" 82 private const val ACCUMULATED_SNOW_SHADER_PATH = "shaders/snow_accumulation.agsl" 83 private const val COLOR_GRADING_SHADER_PATH = "shaders/color_grading_lut.agsl" 84 private const val NOISE_TEXTURE_PATH = "textures/clouds.png" 85 private const val LOOKUP_TABLE_TEXTURE_PATH = "textures/lut_rain_and_fog.png" 86 private const val DEFAULT_INTENSITY = 1f 87 private const val COLOR_GRADING_INTENSITY = 0.7f 88 private const val MAX_SNOW_THICKNESS = 10f 89 } 90 } 91
