Update add-custom-layer.zh.md (#2164)

docs/developer-guide/add-custom-layer.zh.md

@@ -1,4 +1,8 @@
-这里举个例子添加 Relu6，即 std::min(6, std::max(0, val))
+# NCNN增加自定义层
+
+## 举例
+
+这里举个例子添加自定义层次 如Relu6，即 std::min(6, std::max(0, val))
 
 ```
 Input            input   0 1 input
@@ -7,102 +11,165 @@ Relu6            relu6   1 1 conv2d relu6
 Pooling          maxpool 1 1 relu6 maxpool 0=0 1=3 2=2 3=-233 4=0
 ```
 
-## method 1 -- 注册自定义层
-```cpp
+
+
+## 定义源码h文件：src/layer/relu6.h
+
+```CPP
+#ifndef LAYER_RELU6_H
+#define LAYER_RELU6_H
+
 #include "layer.h"
 
-class Relu6 : public ncnn::Layer
+namespace ncnn {
+
+class Relu6 : public Layer
 {
 public:
-    Relu6()
-    {
-        one_blob_only = true;
-        support_inplace = true;
-    }
+    Relu6();
 
-    virtual int forward_inplace(Mat& bottom_top_blob, const Option& opt) const
-    {
+    virtual int forward_inplace(Mat& bottom_top_blob, const Option& opt) const;
+};
+
+} // namespace ncnn
+
+#endif // LAYER_RELU6_H
+```
+
+
+
+## 定义源码CPP文件：src/layer/relu6.cpp
+
+```CPP
+#include "relu6.h"
+
+#include <math.h>
+
+namespace ncnn {
+
+Relu6::Relu6()
+{
+    one_blob_only = true;
+    support_inplace = true;
+}
+
+int Relu6::forward_inplace(Mat& bottom_top_blob, const Option& opt) const
+{
         int w = bottom_top_blob.w;
         int h = bottom_top_blob.h;
         int channels = bottom_top_blob.c;
         int size = w * h;
 
         #pragma omp parallel for num_threads(opt.num_threads)
-        for (int q=0; q<channels; q++)
+        for (int q=0; q < channels; q++)
         {
-            float* outptr = bottom_top_blob.channel(q);
+            float* ptr = bottom_top_blob.channel(q);
 
             for (int i=0; i<size; i++)
             {
-                outptr[i] = std::min(6, std::max(0, outptr[i]));
+                ptr[i] = std::min(6, std::max(0, ptr[i]));
             }
         }
 
         return 0;
-    }
-};
+}
+
+} // namespace ncnn
 
-DEFINE_LAYER_CREATOR(Relu6)
 ```
 
-```cpp
-ncnn::Net net;
-net.register_custom_layer("Relu6", Relu6_layer_creator);
 
-net.load_param("model.param");
-net.load_model("model.bin");
 
-ncnn::Extractor ex = net.create_extractor();
+## 修改 src/CMakeLists.txt 注册Relu6
 
-ex.input("input", inputmat);
-ex.extract("maxpool", maxpoolmat);
+```CPP
+ncnn_add_layer(GroupNorm)
+ncnn_add_layer(LayerNorm)
+ncnn_add_layer(Relu6)
 ```
 
 
-## method 2 -- 处理中间 blob
-```cpp
-ncnn::Net net;
-net.load_param("model.param");
-net.load_model("model.bin");
 
-ncnn::Extractor ex = net.create_extractor();
+## 定义测试用例CPP文件 src/test_relu6.cpp 
 
-ex.input("input", inputmat);
-ex.extract("conv2d", conv2dmat);
+```CPP
+#include "layer/relu6.h"
+#include "testutil.h"
 
-// relu6
-ncnn::Mat relu6mat = conv2dmat.clone();
+static int test_relu6(const ncnn::Mat& a)
 {
-    int w = relu6mat.w;
-    int h = relu6mat.h;
-    int channels = relu6mat.c;
-    int size = w * h;
+    ncnn::ParamDict pd;
+
+    std::vector<ncnn::Mat> weights(0);
 
-    #pragma omp parallel for
-    for (int q=0; q<channels; q++)
+    int ret = test_layer<ncnn::Relu6>("Relu6", pd, weights, a);
+    if (ret != 0)
     {
-        float* outptr = relu6mat.channel(q);
-        for (int i=0; i<size; i++)
-        {
-            outptr[i] = std::min(6, std::max(0, outptr[i]));
-        }
+        fprintf(stderr, "test_relu6 failed a.dims=%d a=(%d %d %d)\n", a.dims, a.w, a.h, a.c);
     }
+
+    return ret;
+}
+
+static int test_relu6_0()
+{
+    return 0
+           || test_relu6(RandomMat(5, 7, 24))
+           || test_relu6(RandomMat(7, 9, 12))
+           || test_relu6(RandomMat(3, 5, 13));
+}
+
+static int test_relu6_1()
+{
+    return 0
+           || test_relu6(RandomMat(15, 24))
+           || test_relu6(RandomMat(17, 12))
+           || test_relu6(RandomMat(19, 15));
+}
+
+static int test_relu6_2()
+{
+    return 0
+           || test_relu6(RandomMat(128))
+           || test_relu6(RandomMat(124))
+           || test_relu6(RandomMat(127));
+}
+
+int main()
+{
+    SRAND(7767517);
+
+    return 0
+           || test_relu6_0()
+           || test_relu6_1()
+           || test_relu6_2();
 }
 
-ex.input("relu6", relu6mat);
-ex.extract("maxpool", maxpoolmat);
+```
+
+
 
+## 修改tests/CMakeLists.txt 注册Relu6测试用例
+
+```CPP
+ncnn_add_layer_test(LSTM)
+ncnn_add_layer_test(Yolov3DetectionOutput)
+ncnn_add_layer_test(Relu6)
 ```
 
-## method 3 -- 直接修改 ncnn
-实现 src/layer/relu6.h
 
-实现 src/layer/relu6.cpp
 
-修改 src/CMakeLists.txt
-```cmake
-ncnn_add_layer(UnaryOp)
-ncnn_add_layer(ConvolutionDepthWise)
-ncnn_add_layer(Padding)
-ncnn_add_layer(Relu6)
+## 编译
+
+```
+按原NCNN步骤编译
 ```
+
+
+
+## 单元测试
+
+```
+./test_relu6
+```
+