godot/drivers/etc1/image_etc.cpp

#include "image_etc.h"
#include "image.h"
#include "rg_etc1.h"
#include "print_string.h"
#include "os/copymem.h"
static void _decompress_etc(Image *p_img) {

	ERR_FAIL_COND(p_img->get_format()!=Image::FORMAT_ETC);

	int imgw = p_img->get_width();
	int imgh = p_img->get_height();
	DVector<uint8_t> src=p_img->get_data();
	DVector<uint8_t> dst;

	DVector<uint8_t>::Read r = src.read();

	int mmc=p_img->get_mipmaps();


	for(int i=0;i<=mmc;i++) {

		dst.resize(dst.size()+imgw*imgh*3);
		const uint8_t *srcbr=&r[p_img->get_mipmap_offset(i)];
		DVector<uint8_t>::Write w = dst.write();

		uint8_t *wptr = &w[dst.size()-imgw*imgh*3];

		int bw=MAX(imgw/4,1);
		int bh=MAX(imgh/4,1);

		for(int y=0;y<bh;y++) {

			for(int x=0;x<bw;x++) {

				uint8_t block[4*4*4];


				rg_etc1::unpack_etc1_block(srcbr,(unsigned int*)block);
				srcbr+=8;

				int maxx=MIN(imgw,4);
				int maxy=MIN(imgh,4);

				for(int yy=0;yy<maxy;yy++) {

					for(int xx=0;xx<maxx;xx++) {

						uint32_t src_ofs = (yy*4+xx)*4;
						uint32_t dst_ofs = ((y*4+yy)*imgw+x*4+xx)*3;
						wptr[dst_ofs+0]=block[src_ofs+0];
						wptr[dst_ofs+1]=block[src_ofs+1];
						wptr[dst_ofs+2]=block[src_ofs+2];

					}
				}

			}

		}

		imgw=MAX(1,imgw/2);
		imgh=MAX(1,imgh/2);
	}


	r=DVector<uint8_t>::Read();
	//print_line("Re Creating ETC into regular image: w "+itos(p_img->get_width())+" h "+itos(p_img->get_height())+" mm "+itos(p_img->get_mipmaps()));
	*p_img=Image(p_img->get_width(),p_img->get_height(),p_img->get_mipmaps(),Image::FORMAT_RGB,dst);
	if (p_img->get_mipmaps())
		p_img->generate_mipmaps(-1,true);


}

static void _compress_etc(Image *p_img) {

	Image img = *p_img;

	int imgw=img.get_width(),imgh=img.get_height();

	ERR_FAIL_COND( nearest_power_of_2(imgw)!=imgw || nearest_power_of_2(imgh)!=imgh );

	if (img.get_format()!=Image::FORMAT_RGB)
		img.convert(Image::FORMAT_RGB);


	int mmc=img.get_mipmaps();
	if (mmc==0)
		img.generate_mipmaps(); // force mipmaps, so it works on most hardware


	DVector<uint8_t> res_data;
	DVector<uint8_t> dst_data;
	DVector<uint8_t>::Read r = img.get_data().read();

	int mc=0;


	rg_etc1::etc1_pack_params pp;
	pp.m_quality=rg_etc1::cLowQuality;
	for(int i=0;i<=mmc;i++) {


		int bw=MAX(imgw/4,1);
		int bh=MAX(imgh/4,1);
		const uint8_t *src = &r[img.get_mipmap_offset(i)];
		int mmsize = MAX(bw,1)*MAX(bh,1)*8;
		dst_data.resize(dst_data.size()+mmsize);
		DVector<uint8_t>::Write w=dst_data.write();
		uint8_t *dst = &w[dst_data.size()-mmsize];


//		print_line("bh: "+itos(bh)+" bw: "+itos(bw));

		for(int y=0;y<bh;y++) {

			for(int x=0;x<bw;x++) {

//				print_line("x: "+itos(x)+" y: "+itos(y));

				uint8_t block[4*4*4];
				zeromem(block,4*4*4);
				uint8_t cblock[8];

				int maxy = MIN(imgh,4);
				int maxx = MIN(imgw,4);


				for(int yy=0;yy<maxy;yy++) {

					for(int xx=0;xx<maxx;xx++) {


						uint32_t dst_ofs = (yy*4+xx)*4;
						uint32_t src_ofs = ((y*4+yy)*imgw+x*4+xx)*3;
						block[dst_ofs+0]=src[src_ofs+0];
						block[dst_ofs+1]=src[src_ofs+1];
						block[dst_ofs+2]=src[src_ofs+2];
						block[dst_ofs+3]=255;

					}
				}

				rg_etc1::pack_etc1_block(cblock, (const unsigned int*)block, pp);
				for(int j=0;j<8;j++) {

					dst[j]=cblock[j];
				}

				dst+=8;
			}

		}

		imgw=MAX(1,imgw/2);
		imgh=MAX(1,imgh/2);
		mc++;

	}

	*p_img=Image(p_img->get_width(),p_img->get_height(),mc-1,Image::FORMAT_ETC,dst_data);


}

void _register_etc1_compress_func() {

	rg_etc1::pack_etc1_block_init();
	Image::_image_compress_etc_func=_compress_etc;
	Image::_image_decompress_etc=_decompress_etc;


}