png: Split library to thirdparty dir and allow unbundling

Uses the new structure agreed upon in #6157, but the thirdparty/ folder
does not behave following a logic similar to that of modules/ yet.

The png driver can't be moved to a module as discussed in #6157, as it's
required by core together with a few other ImageLoader implementations
(see drivers/register_driver_types.cpp:register_core_driver_types())

Dropped the possibility to disable PNG support, it's a core component
of Godot.

1 files changed, 43 insertions, 36 deletions

diff --git a/drivers/png/SCsub b/drivers/png/SCsub
index 96ef9fa5f8..ea2324c0cf 100644
--- a/drivers/png/SCsub
+++ b/drivers/png/SCsub
@@ -1,42 +1,49 @@
 Import('env')
 Import('env_drivers')
 
+# Thirdparty source files
 
-png_sources = [
-	"png/png.c",
-	"png/pngerror.c",
-	"png/pngget.c",
-	"png/pngmem.c",
-	"png/pngpread.c",
-	"png/pngread.c",
-	"png/pngrio.c",
-	"png/pngrtran.c",
-	"png/pngrutil.c",
-	"png/pngset.c",
-	"png/pngtrans.c",
-	"png/pngwio.c",
-	"png/pngwrite.c",
-	"png/pngwtran.c",
-	"png/pngwutil.c",
-	"png/resource_saver_png.cpp",
-	"png/image_loader_png.cpp"
-]
-
-# Currently .ASM filter_neon.S does not compile on NT.
-import os
-if ("neon_enabled" in env and env["neon_enabled"]) and os.name!="nt":
-	env_drivers.Append(CPPFLAGS=["-DPNG_ARM_NEON_OPT=2"])
-	env_neon = env_drivers.Clone();
-	if "S_compiler" in env:
-		env_neon['CC'] = env['S_compiler']
-	#env_neon.Append(CPPFLAGS=["-DPNG_ARM_NEON"])
-	png_sources.append(env_neon.Object("#drivers/png/arm/arm_init.c"))
-	png_sources.append(env_neon.Object("#drivers/png/arm/filter_neon.S"))
-else:
-	env_drivers.Append(CPPFLAGS=["-DPNG_ARM_NEON_OPT=0"])
-
-env.drivers_sources+=png_sources
-
-#env.add_source_files(env.drivers_sources, png_sources)
+if (env["libpng"] == "builtin"):
+	thirdparty_dir = "#thirdparty/libpng/"
+	thirdparty_png_sources = [
+		thirdparty_dir + "png.c",
+		thirdparty_dir + "pngerror.c",
+		thirdparty_dir + "pngget.c",
+		thirdparty_dir + "pngmem.c",
+		thirdparty_dir + "pngpread.c",
+		thirdparty_dir + "pngread.c",
+		thirdparty_dir + "pngrio.c",
+		thirdparty_dir + "pngrtran.c",
+		thirdparty_dir + "pngrutil.c",
+		thirdparty_dir + "pngset.c",
+		thirdparty_dir + "pngtrans.c",
+		thirdparty_dir + "pngwio.c",
+		thirdparty_dir + "pngwrite.c",
+		thirdparty_dir + "pngwtran.c",
+		thirdparty_dir + "pngwutil.c",
+	]
 
+	# Currently .ASM filter_neon.S does not compile on NT.
+	import os
+	if ("neon_enabled" in env and env["neon_enabled"]) and os.name!="nt":
+		env_drivers.Append(CPPFLAGS=["-DPNG_ARM_NEON_OPT=2"])
+		env_neon = env_drivers.Clone();
+		if "S_compiler" in env:
+			env_neon['CC'] = env['S_compiler']
+		#env_neon.Append(CPPFLAGS=["-DPNG_ARM_NEON"])
+		thirdparty_png_sources.append(env_neon.Object(thirdparty_dir + "/arm/arm_init.c"))
+		thirdparty_png_sources.append(env_neon.Object(thirdparty_dir + "/arm/filter_neon.S"))
+	else:
+		env_drivers.Append(CPPFLAGS=["-DPNG_ARM_NEON_OPT=0"])
+
+	#env_drivers.add_source_files(env.drivers_sources, thirdparty_png_sources)
+	env.drivers_sources += thirdparty_png_sources # Concatenation necessary for neon objects it seems?
+	env_drivers.Append(CPPPATH = [thirdparty_dir])
+
+
+# Godot's own source files
+
+env_drivers.add_source_files(env.drivers_sources, "*.cpp")
+
+Export('env_drivers')
 Export('env')