Initial revision

1 files changed, 187 insertions, 0 deletions

diff --git a/lib/gdi/epng.cpp b/lib/gdi/epng.cpp
new file mode 100644
index 00000000..d476ec3a
--- /dev/null
+++ b/lib/gdi/epng.cpp
@@ -0,0 +1,187 @@
+#include <png.h>
+#include <stdio.h>
+#include <lib/gdi/epng.h>
+#include <unistd.h>
+
+gImage *loadPNG(const char *filename)
+{
+	__u8 header[8];
+	FILE *fp=fopen(filename, "rb");
+	
+	gImage *res=0;
+	
+	if (!fp)
+	{
+//		eDebug("couldn't open %s", filename );
+		return 0;
+	}
+	if (!fread(header, 8, 1, fp))
+	{
+		eDebug("couldn't read");
+		fclose(fp);
+		return 0;
+	}
+	if (png_sig_cmp(header, 0, 8))
+	{
+		fclose(fp);
+		return 0;
+	}
+	png_structp png_ptr=png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
+	if (!png_ptr)
+	{
+		eDebug("no pngptr");
+		fclose(fp);
+		return 0;
+	}
+	png_infop info_ptr=png_create_info_struct(png_ptr);
+	if (!info_ptr)
+	{
+		eDebug("no info ptr");
+		png_destroy_read_struct(&png_ptr, (png_infopp)0, (png_infopp)0);
+		fclose(fp);
+		return 0;
+	}
+	png_infop end_info = png_create_info_struct(png_ptr);
+	if (!end_info)
+	{
+		eDebug("no end");
+		png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
+		fclose(fp);
+		return 0;
+	 }
+	if (setjmp(png_ptr->jmpbuf))
+	{
+		eDebug("das war wohl nix");
+		png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+		fclose(fp);
+		if (res)
+			delete res;
+		return 0;
+	}
+	png_init_io(png_ptr, fp);
+	png_set_sig_bytes(png_ptr, 8);
+	png_set_invert_alpha(png_ptr);
+	png_read_info(png_ptr, info_ptr);
+	
+	png_uint_32 width, height;
+	int bit_depth;
+	int color_type;
+	
+	png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, 0, 0, 0);
+	
+//	eDebug("%s: %dx%dx%d png, %d", filename, (int)width, (int)height, (int)bit_depth, color_type);
+	
+	if (color_type != 6)
+	{
+		res=new gImage(eSize(width, height), bit_depth);
+	
+		png_bytep *rowptr=new png_bytep[height];
+	
+		for (unsigned int i=0; i<height; i++)
+			rowptr[i]=((png_byte*)(res->data))+i*res->stride;
+		png_read_rows(png_ptr, rowptr, 0, height);
+	
+		delete rowptr;
+	
+		if (png_get_valid(png_ptr, info_ptr, PNG_INFO_PLTE))
+		{
+			png_color *palette;
+			int num_palette;
+			png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette);
+			if (num_palette)
+				res->clut.data=new gRGB[num_palette];
+			else
+				res->clut.data=0;
+			res->clut.colors=num_palette;
+			
+			for (int i=0; i<num_palette; i++)
+			{
+				res->clut.data[i].a=0;
+				res->clut.data[i].r=palette[i].red;
+				res->clut.data[i].g=palette[i].green;
+				res->clut.data[i].b=palette[i].blue;
+			}
+			if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+			{
+				png_byte *trans;
+				png_get_tRNS(png_ptr, info_ptr, &trans, &num_palette, 0);
+				for (int i=0; i<num_palette; i++)
+					res->clut.data[i].a=255-trans[i];
+			}
+		} else
+		{
+			res->clut.data=0;
+			res->clut.colors=0;
+		}
+		png_read_end(png_ptr, end_info);
+	} else
+		res=0;
+
+	png_destroy_read_struct(&png_ptr, &info_ptr,&end_info);
+	fclose(fp);
+	return res;
+}
+
+int savePNG(const char *filename, gPixmap *pixmap)
+{
+	FILE *fp=fopen(filename, "wb");
+	if (!fp)
+		return -1;
+	png_structp png_ptr=png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
+	if (!png_ptr)
+	{
+		eDebug("write png, couldnt allocate write struct");
+		fclose(fp);
+		unlink(filename);
+		return -2;
+	}
+	png_infop info_ptr=png_create_info_struct(png_ptr);
+	if (!info_ptr)
+	{
+		eDebug("info");
+		png_destroy_write_struct(&png_ptr, 0);
+		fclose(fp);
+		unlink(filename);
+		return -3;
+	}
+	if (setjmp(png_ptr->jmpbuf))
+	{
+		eDebug("error :/");
+		png_destroy_write_struct(&png_ptr, &info_ptr);
+		fclose(fp);
+		unlink(filename);
+		return -4;
+	}
+	png_init_io(png_ptr, fp);
+	png_set_filter(png_ptr, 0, PNG_FILTER_NONE|PNG_FILTER_SUB|PNG_FILTER_PAETH);
+	png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);
+
+	png_set_IHDR(png_ptr, info_ptr, pixmap->x, pixmap->y, pixmap->bpp, 
+		pixmap->clut.data ? PNG_COLOR_TYPE_PALETTE : PNG_COLOR_TYPE_GRAY, 
+		PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+	if (pixmap->clut.data)
+	{
+		png_color palette[pixmap->clut.colors];
+		png_byte trans[pixmap->clut.colors];
+		for (int i=0; i<pixmap->clut.colors; ++i)
+		{
+			palette[i].red=pixmap->clut.data[i].r;
+			palette[i].green=pixmap->clut.data[i].g;
+			palette[i].blue=pixmap->clut.data[i].b;
+			trans[i]=255-pixmap->clut.data[i].a;
+		}
+		png_set_PLTE(png_ptr, info_ptr, palette, pixmap->clut.colors);
+		png_set_tRNS(png_ptr, info_ptr, trans, pixmap->clut.colors, 0);
+	}
+	png_write_info(png_ptr, info_ptr);
+	png_set_packing(png_ptr);
+	png_byte *row_pointers[pixmap->y];
+	for (int i=0; i<pixmap->y; ++i)
+		row_pointers[i]=((png_byte*)pixmap->data)+i*pixmap->stride;
+	png_write_image(png_ptr, row_pointers);
+	png_write_end(png_ptr, info_ptr);
+	png_destroy_write_struct(&png_ptr, &info_ptr);
+	fclose(fp);
+	eDebug("wrote png ! fine !");
+	return 0;
+}