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Android RenderScript 浅谈

news 来源：原创 2024/5/6 3:30:01

前言

RenderScript是一个Google出品的，在Android平台上的并行计算框架，官方的简介是说RenderScript运行时可在设备上提供的多个处理器（如多核 CPU 和 GPU）间并行调度工作。在日常Android开发中，RenderScript主要用于图像处理。比如对图片做高斯模糊等，都可以用RenderScript处理。

在这里插入图片描述
内容来自RenderScript 概览

扯淡的文档说明, 加上这玩意要被舍弃了, 觉得有点可惜
在这里插入图片描述
内容来自从 RenderScript 迁移

使用

总的来说，RenderScript能干的事情很多，但有限。常见用于处理Bitmap的效果、转换。
如(参考RenderScript Intrinsics Replacement Toolkit)：

blend,
blur,
color matrix,
convolve,
histogram and histogramDot,
LUT (lookup table) and LUT 3D,
resize, and YUV to RGB.

反色参考代码:

uchar4 RS_KERNEL invert(uchar4 in, uint32_t x, uint32_t y) {
  uchar4 out = in;
  out.r = 255 - in.r;
  out.g = 255 - in.g;
  out.b = 255 - in.b;
  return out;
}

对应java调用代码

	public static Bitmap invert(Context context, Bitmap bm){
		Bitmap bmOut = Bitmap.createBitmap(bm);
		RenderScript RS = RenderScript.create(context);
		ScriptC_singlesource script = new ScriptC_singlesource(RS);
		//Allocation inputAllocation = Allocation.createFromBitmapResource(
		//		RS, getResources(), R.drawable.image);
		Allocation inputAllocation = Allocation.createFromBitmap(RS, bm);
		Allocation outputAllocation = Allocation.createFromBitmap(RS, bmOut);
		//Allocation outputAllocation = Allocation.createTyped(
		//		RS, inputAllocation.getType(),
		//		Allocation.USAGE_SCRIPT | Allocation.USAGE_IO_OUTPUT);
		script.forEach_invert(inputAllocation, outputAllocation);
		outputAllocation.copyTo(bmOut);
		RS.destroy();
		return bmOut;
	}

其他基础用法案例可以参考本文末尾参考部分连接资料，接下来是一些新的尝试。

前面大部分的接口的入参都是bitmap, 如果要使用int[] 或 **byte[]**呢？

//https://blog.csdn.net/oDongFangZhiZi/article/details/71422510
int __attribute__((kernel)) test0(int in, uint32_t x) {
    int out = in;
    out = x;
    return out;
}

	public static void test0(Context context, int[] src) {

		// 创建 RenderScript 对象
		RenderScript rs = RenderScript.create(context);

		// 创建输入、输出 Allocation
		Allocation allIn  = Allocation.createSized(rs, Element.I32(rs), src.length);
		allIn.copyFrom(src);

		byte[] out = new byte[src.length];
		Allocation allOut  = Allocation.createSized(rs, Element.I32(rs), src.length);

		ScriptC_test rsTest = new ScriptC_test(rs);
		rsTest.forEach_test0(allIn, allOut);
		allOut.copyTo(out);
		// 释放资源
		rs.destroy();
	}

重点在于Allocation.createSized(rs, Element.I32(rs), src.length); 关于Element的文档，真的让人无从下手…
在这里插入图片描述

int[] 相对简单，如果在RS中使用的是uchar4，入参怎么传？答案是可以用byte[]（非标准答案，仅供参考）

//map for byte[4]
//rgba = [0][1][2][3]
uchar4 __attribute__((kernel)) test1(uchar4 in, uint32_t x, uint32_t y) {
    uchar4 out = in;
    //out.r = x;
    out.g = x + 1;
    out.b = x + 2;
    out.a = x + 3;
    return out;
}

	public static void test(Context context, byte[] src) {
		// 创建 RenderScript 对象
		RenderScript rs = RenderScript.create(context);

		// 创建输入、输出 Allocation
		Allocation allIn  = Allocation.createSized(rs, Element.RGBA_8888(rs), src.length/4);
		allIn.copyFrom(src);

		byte[] out = new byte[src.length];
		Allocation allOut  = Allocation.createSized(rs, Element.RGBA_8888(rs), src.length/4);

		ScriptC_test rsTest = new ScriptC_test(rs);
		rsTest.forEach_test1(allIn, allOut);
		allOut.copyTo(out);
		// 释放资源
		rs.destroy();
	}

test(getContext(), new byte[]{
				10, 0, 0, 0,
				11, 0, 0, 0,
				12, 0, 0, 0,
				13, 0, 0, 0,
				14, 0, 0, 0,
				15, 0, 0, 0,
				16, 0, 0, 0,
				17, 0, 0, 0});
//结果：
//0x0a,0x01,0x02,0x03,
//0x0b,0x02,0x03,0x04,
//0x0c,0x03,0x04,0x05,
//0x0d,0x04,0x05,0x06,
//0x0e,0x05,0x06,0x07,
//0x0f,0x06,0x07,0x08,
//0x10,0x07,0x08,0x09,
//0x11,0x08,0x09,0x0a

RenderScript源码位置

frameworks/base/rs/
├── java
│ └── android
│ └── renderscript
│ ├── AllocationAdapter.java
│ ├── Allocation.java
│ ├── BaseObj.java
│ ├── Byte2.java
│ ├── Byte3.java
│ ├── Byte4.java
│ ├── Double2.java
│ ├── Double3.java
│ ├── Double4.java
│ ├── Element.java
│ ├── FieldPacker.java
│ ├── FileA3D.java
│ ├── Float2.java
│ ├── Float3.java
│ ├── Float4.java
│ ├── Font.java
│ ├── Int2.java
│ ├── Int3.java
│ ├── Int4.java
│ ├── Long2.java
│ ├── Long3.java
│ ├── Long4.java
│ ├── Matrix2f.java
│ ├── Matrix3f.java
│ ├── Matrix4f.java
│ ├── Mesh.java
│ ├── package.html
│ ├── ProgramFragmentFixedFunction.java
│ ├── ProgramFragment.java
│ ├── Program.java
│ ├── ProgramRaster.java
│ ├── ProgramStore.java
│ ├── ProgramVertexFixedFunction.java
│ ├── ProgramVertex.java
│ ├── RenderScriptCacheDir.java
│ ├── RenderScriptGL.java
│ ├── RenderScript.java
│ ├── RSDriverException.java
│ ├── RSIllegalArgumentException.java
│ ├── RSInvalidStateException.java
│ ├── RSRuntimeException.java
│ ├── RSSurfaceView.java
│ ├── RSTextureView.java
│ ├── Sampler.java
│ ├── ScriptC.java
│ ├── ScriptGroup.java
│ ├── ScriptIntrinsic3DLUT.java
│ ├── ScriptIntrinsicBLAS.java
│ ├── ScriptIntrinsicBlend.java
│ ├── ScriptIntrinsicBlur.java
│ ├── ScriptIntrinsicColorMatrix.java
│ ├── ScriptIntrinsicConvolve3x3.java
│ ├── ScriptIntrinsicConvolve5x5.java
│ ├── ScriptIntrinsicHistogram.java
│ ├── ScriptIntrinsic.java
│ ├── ScriptIntrinsicLUT.java
│ ├── ScriptIntrinsicResize.java
│ ├── ScriptIntrinsicYuvToRGB.java
│ ├── Script.java
│ ├── Short2.java
│ ├── Short3.java
│ ├── Short4.java
│ └── Type.java
├── jni
│ ├── Android.mk
│ └── android_renderscript_RenderScript.cpp
└── OWNERS