Use g2c for png decoding

.github/workflows/developer.yml

@@ -62,7 +62,7 @@ jobs:
         export CFLAGS='-Wall -g -fprofile-abs-path -fprofile-arcs -ftest-coverage -O0 -I/home/runner/work/wgrib2/wgrib2/nceplibs/NCEPLIBS-g2c/include'
         export FCFLAGS='-Wall -g -fprofile-abs-path -fprofile-arcs -ftest-coverage -O0'
         export FFLAGS='-Wall -g -fprofile-abs-path -fprofile-arcs -ftest-coverage -O0'
-        cmake .. -DENABLE_DOCS=ON -DFTP_TEST_FILES=ON -DCMAKE_PREFIX_PATH="$GITHUB_WORKSPACE/nceplibs/NCEPLIBS-ip;$GITHUB_WORKSPACE/nceplibs/jasper;$GITHUB_WORKSPACE/nceplibs/NCEPLIBS-g2c" -DTEST_FILE_DIR=/home/runner/data -DMAKE_FTN_API=ON -DUSE_NETCDF4=ON -DUSE_AEC=ON -DUSE_IPOLATES=ON -DUSE_JASPER=ON
+        cmake .. -DENABLE_DOCS=ON -DFTP_TEST_FILES=ON -DCMAKE_PREFIX_PATH="$GITHUB_WORKSPACE/nceplibs/NCEPLIBS-ip;$GITHUB_WORKSPACE/nceplibs/jasper;$GITHUB_WORKSPACE/nceplibs/NCEPLIBS-g2c" -DTEST_FILE_DIR=/home/runner/data -DMAKE_FTN_API=ON -DUSE_NETCDF4=ON -DUSE_AEC=ON -DUSE_IPOLATES=ON -DUSE_JASPER=ON -DUSE_PNG=ON
         make VERBOSE=1
         ctest --verbose --output-on-failure --rerun-failed
         gcovr --root .. -v  --html-details --exclude ../tests --exclude CMakeFiles --print-summary -o test-coverage.html &> /dev/null

CMakeLists.txt

@@ -131,8 +131,7 @@ endif()
 
 message(STATUS "Checking if the user wants to use PNG...")
 if(USE_PNG)
-  find_package(ZLIB REQUIRED)
-  find_package(PNG REQUIRED)
+  find_package(g2c 1.9.0 CONFIG REQUIRED)
 endif()
 
 # Find required packages to use AEC

spack/package.py

@@ -175,11 +175,12 @@ def url_for_version(self, version):
     depends_on("[email protected]:", when="@3.2: +aec")
     depends_on("netcdf-c", when="@3.2: +netcdf4")
     depends_on("jasper@:2", when="@3.2:3.4 +jasper")
-    depends_on("g2c", when="@develop +jasper")
-    depends_on("zlib-api", when="@3.2: +png")
-    depends_on("libpng", when="@3.2: +png")
+    depends_on("g2c@develop +jasper", when="@develop +jasper")
+    depends_on("zlib-api", when="@3.2:3.4 +png")
+    depends_on("libpng", when="@3.2:3.4 +png")
+    depends_on("g2c@develop +png", when="@develop +png")
     depends_on("openjpeg", when="@3.2:3.4 +openjpeg")
-    depends_on("g2c +openjpeg", when="@develop +openjpeg")
+    depends_on("g2c@develop +openjpeg", when="@develop +openjpeg")
 
     @when("@:2 ^[email protected]:")
 

wgrib2/CMakeLists.txt

@@ -22,10 +22,9 @@ Alias.c Ave_test.c Ave_var.c Bbox.c bitstream.c Box_ave.c
 Check_pdt_size.c Checksum.c Cluster.c cname.c codetable_4_230.c
 CodeTable.c Code_Values.c Code_Values_JMA.c complex_pk.c Config.c
 copy.c crc32.c Cress_lola.c Csv.c Csv_long.c cubed_sphere2ll.c
-CubeFace2global.c Cyclic.c Data.c dec_png_clone.c
-Dump.c Earth.c Else.c End.c Endif.c Ensemble.c
-Ens_processing.c Ens_qc.c EOF.c Export_lonlat.c ExtName.c
-fatal_error.c Fcst_ave.c ffopen.c Fi.c File.c Fix_CFSv2_fcst.c
+CubeFace2global.c Cyclic.c Data.c Dump.c Earth.c Else.c End.c
+Endif.c Ensemble.c Ens_processing.c Ens_qc.c EOF.c Export_lonlat.c
+ExtName.c fatal_error.c Fcst_ave.c ffopen.c Fi.c File.c Fix_CFSv2_fcst.c
 Fix_ncep_2.c Fix_ncep_3.c Fix_ncep_4.c Fix_ncep.c Fix_undef.c
 FlagTable.c flt2ieee.c flt2ieee_nan.c Flush.c fnlist.c For.c Ftime1.c
 Ftime2.c Ftime.c Ftn_api.c gaussian2ij.c Gctpc.c gctpc_ll2xy.c GDT.c
@@ -108,10 +107,6 @@ if(USE_NETCDF)
   target_link_libraries(wgrib2_exe PUBLIC NetCDF::NetCDF_C)
 endif()
 
-if(USE_PNG)
-  target_link_libraries(obj_lib PUBLIC PNG::PNG)
-endif()
-
 if(USE_OPENMP)
   target_link_libraries(obj_lib PUBLIC OpenMP::OpenMP_C)
   if(BUILD_SHARED_LIB)
@@ -143,7 +138,7 @@ if(USE_AEC)
   target_link_libraries(wgrib2_exe PRIVATE ${LIBAEC_LIBRARIES})
 endif()
 
-if(USE_JASPER OR USE_OPENJPEG)
+if(USE_JASPER OR USE_OPENJPEG OR USE_PNG)
   target_link_libraries(obj_lib PUBLIC g2c::g2c)
   target_link_libraries(wgrib2_exe PRIVATE g2c::g2c)
 endif()

wgrib2/unpk.c

@@ -17,8 +17,7 @@
 #endif
 
 #ifdef USE_PNG
-   #include <png.h>
-   int i;
+    #include "grib2.h"
 #endif
 
 #ifdef USE_AEC
@@ -47,7 +46,7 @@ int unpk_grib(unsigned char **sec, float *data) {
     double bin_scale, dec_scale, b;
 
 #ifdef USE_PNG
-    int width, height;
+    int i, width, height;
 #endif
 
 #if (defined USE_JASPER || defined USE_OPENJPEG)
@@ -251,7 +250,7 @@ int unpk_grib(unsigned char **sec, float *data) {
 	if ((c = (unsigned char *) malloc(4*sizeof(char) * (size_t) ndata)) == NULL)
             fatal_error("unpk: png decode allocation error", "");
 
-	i = (int) dec_png_clone(sec[7]+5, &width, &height, (unsigned char *) c, &nbits, ndata);
+    i = g2c_dec_png(sec[7]+5, &width, &height, (unsigned char *) c);
 	if (i) fatal_error_i("unpk: png decode error %d",i);
 	mask_pointer = (bitmap_flag == 255) ? NULL : sec[6] + 6;
 

wgrib2/wgrib2.h

@@ -502,7 +502,7 @@ int wrt_sec(unsigned const char *sec0, unsigned const char *sec1, unsigned const
 int scaling(unsigned char **sec, double *base, int *decimal, int *binary, int *nbits);
 unsigned char *mk_bms(float *data, unsigned int *ndata);
 
-int dec_png_clone(unsigned char *pngbuf,int *width,int *height, unsigned char *cout, int *grib2_bit_depth, unsigned int ndata);
+int g2c_dec_png(unsigned char *pngbuf, int *width, int *height, unsigned char *cout);
 int ieee_grib_out(unsigned char **sec, float *data, unsigned int ndata, struct seq_file *out);
 int jpeg_grib_out(unsigned char **sec, float *data, unsigned int ndata, 
     int nx, int ny, int use_scale, int dec_scale, int bin_scale, FILE *out);