added a newly test that it's NormalCompressTest, test result was OK.

CMakeLists.txt

@@ -39,3 +39,6 @@ cm_example_project(SplitStringTest)
 
 add_executable(CreateBinaryH CreateBinaryH.cpp)
 cm_example_project(CreateBinaryH)
+
+add_executable(NormalCompressTest NormalCompressTest.cpp)
+CM_EXAMPLE_PROJECT(NormalCompressTest)

NormalCompressTest.cpp

@@ -0,0 +1,84 @@
+#include<hgl/graph/NormalData.h>
+#include<hgl/util/imgfmt/tga.h>
+#include<hgl/filesystem/FileSystem.h>
+#include<hgl/io/FileOutputStream.h>
+#include<iostream>
+
+using namespace hgl;
+using namespace hgl::filesystem;
+using namespace hgl::util;
+
+static uint8 *      file_data=nullptr;
+static int64        file_length=0;
+static TGAHeader *  tga_header=nullptr;
+static uint8 *      bitmap_data=nullptr;
+static uint8 *      origin_bitmap_data=nullptr;
+static uint         bitmap_bytes=0;
+static uint         pixel_count=0;
+
+void SaveTGA(const os_char *filename)
+{
+    SaveMemoryToFile(filename,file_data,file_length);
+}
+
+void TwoBytesNormalTest()
+{
+    uint8 *two_bytes_normal=new uint8[pixel_count*2];
+
+    Normal3to2(two_bytes_normal,origin_bitmap_data,pixel_count);
+
+    Normal2to3(bitmap_data,two_bytes_normal,pixel_count);
+
+    SaveTGA(OS_TEXT("CompressNormal.tga"));
+
+    {
+        uint8 *tp=bitmap_data;
+        uint8 *sp=origin_bitmap_data;
+
+        for(uint i=0;i<pixel_count*3;i++)
+        {
+            *tp=abs(*tp-*sp);
+            ++tp;
+            ++sp;
+        }
+
+        SaveTGA(OS_TEXT("CompressNormalDiff.tga"));
+    }
+
+    delete[] two_bytes_normal;
+}
+
+int main(int,char **)
+{
+    file_data=(uint8 *)LoadFileToMemory(OS_TEXT("TestNormal.tga"),file_length);
+
+    if(!file_data)
+    {
+        std::cerr<<"load file <TestNormal.tga> error!"<<std::endl;
+        return(-1);
+    }
+
+    tga_header=(TGAHeader *)file_data;
+
+    if(tga_header->bit!=24)
+    {
+        std::cerr<<"<TestNormal.tga> is not 24bits image!"<<std::endl;
+        delete[] file_data;
+        return(-1);
+    }
+
+    bitmap_data=file_data+sizeof(TGAHeader);
+
+    pixel_count=tga_header->width*tga_header->height;
+
+    bitmap_bytes=pixel_count*3;
+
+    origin_bitmap_data=new uint8[bitmap_bytes];
+    memcpy(origin_bitmap_data,bitmap_data,bitmap_bytes);
+
+    TwoBytesNormalTest();
+
+    delete[] origin_bitmap_data;
+    delete[] file_data;
+    return 0;
+}