Add etc1(pkm) texture loading support

drivers/etc1/SCsub

@@ -3,7 +3,8 @@ Import('env')
 
 etc_sources = [
 	"etc1/image_etc.cpp",
-	"etc1/rg_etc1.cpp"
+	"etc1/rg_etc1.cpp",
+	"etc1/texture_loader_pkm.cpp"
 ]
 
 if (env["etc1"] != "no"):

drivers/etc1/texture_loader_pkm.cpp

@@ -0,0 +1,84 @@
+#include "texture_loader_pkm.h"
+#include "os/file_access.h"
+#include <string.h>
+
+struct ETC1Header {
+    char tag[6];			// "PKM 10"
+    uint16_t format;        // Format == number of mips (== zero)
+    uint16_t texWidth;      // Texture dimensions, multiple of 4 (big-endian)
+    uint16_t texHeight;
+    uint16_t origWidth;     // Original dimensions (big-endian)
+    uint16_t origHeight;
+};
+
+RES ResourceFormatPKM::load(const String &p_path, const String& p_original_path, Error *r_error) {
+
+	if (r_error)
+		*r_error=ERR_CANT_OPEN;
+
+	Error err;
+	FileAccess *f = FileAccess::open(p_path,FileAccess::READ,&err);
+	if (!f)
+		return RES();
+
+	FileAccessRef fref(f);
+	if (r_error)
+		*r_error=ERR_FILE_CORRUPT;
+
+	ERR_EXPLAIN("Unable to open PKM texture file: "+p_path);
+	ERR_FAIL_COND_V(err!=OK,RES());
+
+	// big endian
+	f->set_endian_swap(true);
+
+	ETC1Header h;
+	ERR_EXPLAIN("Invalid or Unsupported PKM texture file: "+p_path);
+	f->get_buffer((uint8_t *) &h.tag, sizeof(h.tag));
+	if(strncmp(h.tag, "PKM 10", sizeof(h.tag)))
+		ERR_FAIL_V(RES());
+
+	h.format = f->get_16();
+	h.texWidth = f->get_16();
+	h.texHeight = f->get_16();
+	h.origWidth = f->get_16();
+	h.origHeight = f->get_16();
+
+	DVector<uint8_t> src_data;
+
+	uint32_t size = h.texWidth * h.texHeight / 2;
+	src_data.resize(size);
+	DVector<uint8_t>::Write wb = src_data.write();
+	f->get_buffer(wb.ptr(),size);
+	wb=DVector<uint8_t>::Write();
+
+	int mipmaps = h.format;
+	int width = h.origWidth;
+	int height = h.origHeight;
+
+	Image img(width,height,mipmaps,Image::FORMAT_ETC,src_data);
+
+	Ref<ImageTexture> texture = memnew( ImageTexture );
+	texture->create_from_image(img);
+
+	if (r_error)
+		*r_error=OK;
+
+	return texture;
+}
+
+void ResourceFormatPKM::get_recognized_extensions(List<String> *p_extensions) const {
+
+	p_extensions->push_back("pkm");
+}
+
+bool ResourceFormatPKM::handles_type(const String& p_type) const {
+
+	return ObjectTypeDB::is_type(p_type,"Texture");
+}
+
+String ResourceFormatPKM::get_resource_type(const String &p_path) const {
+
+	if (p_path.extension().to_lower()=="pkm")
+		return "ImageTexture";
+	return "";
+}

drivers/etc1/texture_loader_pkm.h

@@ -0,0 +1,18 @@
+#ifndef TEXTURE_LOADER_PKM_H
+#define TEXTURE_LOADER_PKM_H
+
+#include "scene/resources/texture.h"
+#include "io/resource_loader.h"
+
+class ResourceFormatPKM : public ResourceFormatLoader{
+public:
+
+	virtual RES load(const String &p_path,const String& p_original_path="",Error *r_error=NULL);
+	virtual void get_recognized_extensions(List<String> *p_extensions) const;
+	virtual bool handles_type(const String& p_type) const;
+	virtual String get_resource_type(const String &p_path) const;
+
+	virtual ~ResourceFormatPKM() {}
+};
+
+#endif // TEXTURE_LOADER_PKM_H

drivers/register_driver_types.cpp

@@ -16,6 +16,7 @@
 #include "png/resource_saver_png.h"
 #include "jpegd/image_loader_jpegd.h"
 #include "dds/texture_loader_dds.h"
+#include "etc1/texture_loader_pkm.h"
 #include "pvr/texture_loader_pvr.h"
 #include "etc1/image_etc.h"
 #include "chibi/event_stream_chibi.h"
@@ -79,6 +80,10 @@ static ImageLoaderJPG *image_loader_jpg=NULL;
 static ResourceFormatDDS *resource_loader_dds=NULL;
 #endif
 
+#ifdef ETC1_ENABLED
+static ResourceFormatPKM *resource_loader_pkm=NULL;
+#endif
+
 
 #ifdef PVR_ENABLED
 static ResourceFormatPVR *resource_loader_pvr=NULL;
@@ -197,6 +202,11 @@ void register_driver_types() {
 	ResourceLoader::add_resource_format_loader(resource_loader_dds );
 #endif
 
+#ifdef ETC1_ENABLED
+	resource_loader_pkm = memnew( ResourceFormatPKM );
+	ResourceLoader::add_resource_format_loader(resource_loader_pkm);
+#endif
+
 #ifdef PVR_ENABLED
 	resource_loader_pvr = memnew( ResourceFormatPVR );
 	ResourceLoader::add_resource_format_loader(resource_loader_pvr );
@@ -280,6 +290,10 @@ void unregister_driver_types() {
 	memdelete(resource_loader_dds);
 #endif
 
+#ifdef ETC1_ENABLED
+	memdelete(resource_loader_pkm);
+#endif
+
 #ifdef PVR_ENABLED
 	memdelete(resource_loader_pvr);
 #endif