cvar_t gl_texturecompression_reflectmask = {CVAR_SAVE, "gl_texturecompression_reflectmask", "1", "whether to compress reflection cubemap masks (mask of which areas of the texture should reflect the generic shiny cubemap)"};
cvar_t gl_nopartialtextureupdates = {CVAR_SAVE, "gl_nopartialtextureupdates", "1", "use alternate path for dynamic lightmap updates that avoids a possibly slow code path in the driver"};
cvar_t r_texture_dds_load_alphamode = {0, "r_texture_dds_load_alphamode", "1", "0: trust DDPF_ALPHAPIXELS flag, 1: texture format and brute force search if ambigous, 2: texture format only"};
+cvar_t r_texture_dds_swdecode = {0, "r_texture_dds_swdecode", "0", "0: don't software decode DDS, 1: software decode DDS if unsupported, 2: always software decode DDS"};
qboolean gl_filter_force = false;
int gl_filter_min = GL_LINEAR_MIPMAP_LINEAR;
GLTEXTURETYPE_2D,
GLTEXTURETYPE_3D,
GLTEXTURETYPE_CUBEMAP,
- GLTEXTURETYPE_RECTANGLE,
GLTEXTURETYPE_TOTAL
}
gltexturetype_t;
-static int gltexturetypeenums[GLTEXTURETYPE_TOTAL] = {GL_TEXTURE_2D, GL_TEXTURE_3D, GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_RECTANGLE_ARB};
-static int gltexturetypedimensions[GLTEXTURETYPE_TOTAL] = {2, 3, 2, 2};
+static int gltexturetypeenums[GLTEXTURETYPE_TOTAL] = {GL_TEXTURE_2D, GL_TEXTURE_3D, GL_TEXTURE_CUBE_MAP_ARB};
+static int gltexturetypedimensions[GLTEXTURETYPE_TOTAL] = {2, 3, 2};
static int cubemapside[6] =
{
GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB,
// d3d stuff the backend needs
void *d3dtexture;
#ifdef SUPPORTD3D
+ qboolean d3disdepthsurface; // for depth/stencil surfaces
int d3dformat;
int d3dusage;
int d3dpool;
else
Host_Error("R_FreeTexture: texture \"%s\" not linked in pool", glt->identifier);
- if (glt->texnum)
+ switch(vid.renderpath)
{
- CHECKGLERROR
- qglDeleteTextures(1, (GLuint *)&glt->texnum);CHECKGLERROR
+ case RENDERPATH_GL11:
+ case RENDERPATH_GL13:
+ case RENDERPATH_GL20:
+ case RENDERPATH_CGGL:
+ if (glt->texnum)
+ {
+ CHECKGLERROR
+ qglDeleteTextures(1, (GLuint *)&glt->texnum);CHECKGLERROR
+ }
+ break;
+ case RENDERPATH_D3D9:
+#ifdef SUPPORTD3D
+ if (glt->d3disdepthsurface)
+ IDirect3DSurface9_Release((IDirect3DSurface9 *)glt->d3dtexture);
+ else if (glt->tiledepth > 1)
+ IDirect3DVolumeTexture9_Release((IDirect3DVolumeTexture9 *)glt->d3dtexture);
+ else if (glt->sides == 6)
+ IDirect3DCubeTexture9_Release((IDirect3DCubeTexture9 *)glt->d3dtexture);
+ else
+ IDirect3DTexture9_Release((IDirect3DTexture9 *)glt->d3dtexture);
+ glt->d3dtexture = NULL;
+#endif
+ break;
+ case RENDERPATH_D3D10:
+ Con_DPrintf("FIXME D3D10 %s:%i %s\n", __FILE__, __LINE__, __FUNCTION__);
+ break;
+ case RENDERPATH_D3D11:
+ Con_DPrintf("FIXME D3D11 %s:%i %s\n", __FILE__, __LINE__, __FUNCTION__);
+ break;
}
if (glt->inputtexels)
for (glt = pool->gltchain;glt;glt = glt->chain)
{
// only update already uploaded images
- if (glt->d3dtexture && (gl_filter_force || !(glt->flags & (TEXF_FORCENEAREST | TEXF_FORCELINEAR))))
+ if (glt->d3dtexture && !glt->d3disdepthsurface && (gl_filter_force || !(glt->flags & (TEXF_FORCENEAREST | TEXF_FORCELINEAR))))
{
if (glt->flags & TEXF_MIPMAP)
{
case RENDERPATH_D3D11:
break;
case RENDERPATH_D3D9:
+#if 0
// for some reason the REF rasterizer (and hence the PIX debugger) does not like small textures...
if (texturetype == GLTEXTURETYPE_2D)
{
width2 = max(width2, 2);
height2 = max(height2, 2);
}
+#endif
break;
}
break;
case RENDERPATH_D3D9:
#ifdef SUPPORTD3D
- if (glt->tiledepth > 1)
+ if (glt->d3disdepthsurface)
+ IDirect3DSurface9_Release((IDirect3DSurface9 *)glt->d3dtexture);
+ else if (glt->tiledepth > 1)
IDirect3DVolumeTexture9_Release((IDirect3DVolumeTexture9 *)glt->d3dtexture);
else if (glt->sides == 6)
IDirect3DCubeTexture9_Release((IDirect3DCubeTexture9 *)glt->d3dtexture);
#ifdef SUPPORTD3D
{
HRESULT d3dresult;
- if (glt->tiledepth > 1)
+ if (glt->d3disdepthsurface)
+ {
+ if (FAILED(d3dresult = IDirect3DDevice9_CreateDepthStencilSurface(vid_d3d9dev, glt->tilewidth, glt->tileheight, (D3DFORMAT)glt->d3dformat, D3DMULTISAMPLE_NONE, 0, false, (IDirect3DSurface9 **)&glt->d3dtexture, NULL)))
+ Sys_Error("IDirect3DDevice9_CreateDepthStencilSurface failed!");
+ }
+ else if (glt->tiledepth > 1)
{
if (FAILED(d3dresult = IDirect3DDevice9_CreateVolumeTexture(vid_d3d9dev, glt->tilewidth, glt->tileheight, glt->tiledepth, glt->miplevels, glt->d3dusage, (D3DFORMAT)glt->d3dformat, (D3DPOOL)glt->d3dpool, (IDirect3DVolumeTexture9 **)&glt->d3dtexture, NULL)))
Sys_Error("IDirect3DDevice9_CreateVolumeTexture failed!");
Cvar_RegisterVariable (&gl_texturecompression_reflectmask);
Cvar_RegisterVariable (&gl_nopartialtextureupdates);
Cvar_RegisterVariable (&r_texture_dds_load_alphamode);
+ Cvar_RegisterVariable (&r_texture_dds_swdecode);
R_RegisterModule("R_Textures", r_textures_start, r_textures_shutdown, r_textures_newmap, r_textures_devicelost, r_textures_devicerestored);
}
prevbuffer = colorconvertbuffer;
}
+ if (glt->flags & TEXF_RGBMULTIPLYBYALPHA)
+ {
+ // multiply RGB channels by A channel before uploading
+ int alpha;
+ for (i = 0;i < width*height*depth*4;i += 4)
+ {
+ alpha = prevbuffer[i+3];
+ colorconvertbuffer[i] = (prevbuffer[i] * alpha) >> 8;
+ colorconvertbuffer[i+1] = (prevbuffer[i+1] * alpha) >> 8;
+ colorconvertbuffer[i+2] = (prevbuffer[i+2] * alpha) >> 8;
+ colorconvertbuffer[i+3] = alpha;
+ }
+ prevbuffer = colorconvertbuffer;
+ }
+
// scale up to a power of 2 size (if appropriate)
if (glt->inputwidth != width || glt->inputheight != height || glt->inputdepth != depth)
{
}
}
break;
- case GLTEXTURETYPE_RECTANGLE:
- qglTexImage2D(GL_TEXTURE_RECTANGLE_ARB, mip++, glt->glinternalformat, width, height, 0, glt->glformat, glt->gltype, NULL);CHECKGLERROR
- break;
}
GL_SetupTextureParameters(glt->flags, glt->textype->textype, glt->texturetype);
qglBindTexture(gltexturetypeenums[glt->texturetype], oldbindtexnum);CHECKGLERROR
}
}
break;
- case GLTEXTURETYPE_RECTANGLE:
- Sys_Error("Direct3D does not have RECTANGLE textures\n");
- break;
}
}
glt->d3daddressw = 0;
if (cls.state == ca_dedicated)
return NULL;
- if (texturetype == GLTEXTURETYPE_RECTANGLE && !vid.support.arb_texture_rectangle)
- {
- Con_Printf ("R_LoadTexture: rectangle texture not supported by driver\n");
- return NULL;
- }
if (texturetype == GLTEXTURETYPE_CUBEMAP && !vid.support.arb_texture_cube_map)
{
Con_Printf ("R_LoadTexture: cubemap texture not supported by driver\n");
glt->d3dformat = d3dformat;
glt->d3dusage = d3dusage;
glt->d3dpool = d3dpool;
- if (glt->tiledepth > 1)
+ glt->d3disdepthsurface = textype == TEXTYPE_SHADOWMAP;
+ if (glt->d3disdepthsurface)
+ {
+ if (FAILED(d3dresult = IDirect3DDevice9_CreateDepthStencilSurface(vid_d3d9dev, glt->tilewidth, glt->tileheight, (D3DFORMAT)glt->d3dformat, D3DMULTISAMPLE_NONE, 0, false, (IDirect3DSurface9 **)&glt->d3dtexture, NULL)))
+ Sys_Error("IDirect3DDevice9_CreateDepthStencilSurface failed!");
+ }
+ else if (glt->tiledepth > 1)
{
if (FAILED(d3dresult = IDirect3DDevice9_CreateVolumeTexture(vid_d3d9dev, glt->tilewidth, glt->tileheight, glt->tiledepth, glt->miplevels, glt->d3dusage, (D3DFORMAT)glt->d3dformat, (D3DPOOL)glt->d3dpool, (IDirect3DVolumeTexture9 **)&glt->d3dtexture, NULL)))
Sys_Error("IDirect3DDevice9_CreateVolumeTexture failed!");
return R_SetupTexture(rtexturepool, identifier, width, width, 1, 6, flags, miplevel, textype, GLTEXTURETYPE_CUBEMAP, data, palette);
}
-rtexture_t *R_LoadTextureRectangle(rtexturepool_t *rtexturepool, const char *identifier, int width, int height, const unsigned char *data, textype_t textype, int flags, int miplevel, const unsigned int *palette)
-{
- return R_SetupTexture(rtexturepool, identifier, width, height, 1, 1, flags, miplevel, textype, GLTEXTURETYPE_RECTANGLE, data, palette);
-}
-
static int R_ShadowMapTextureFlags(int precision, qboolean filter)
{
int flags = TEXF_RENDERTARGET | TEXF_CLAMP;
return flags;
}
-rtexture_t *R_LoadTextureShadowMapRectangle(rtexturepool_t *rtexturepool, const char *identifier, int width, int height, int precision, qboolean filter)
-{
- return R_SetupTexture(rtexturepool, identifier, width, height, 1, 1, R_ShadowMapTextureFlags(precision, filter), -1, TEXTYPE_SHADOWMAP, GLTEXTURETYPE_RECTANGLE, NULL, NULL);
-}
-
rtexture_t *R_LoadTextureShadowMap2D(rtexturepool_t *rtexturepool, const char *identifier, int width, int height, int precision, qboolean filter)
{
return R_SetupTexture(rtexturepool, identifier, width, height, 1, 1, R_ShadowMapTextureFlags(precision, filter), -1, TEXTYPE_SHADOWMAP, GLTEXTURETYPE_2D, NULL, NULL);
}
-rtexture_t *R_LoadTextureShadowMapCube(rtexturepool_t *rtexturepool, const char *identifier, int width, int precision, qboolean filter)
-{
- return R_SetupTexture(rtexturepool, identifier, width, width, 1, 6, R_ShadowMapTextureFlags(precision, filter), -1, TEXTYPE_SHADOWMAP, GLTEXTURETYPE_CUBEMAP, NULL, NULL);
-}
-
int R_SaveTextureDDSFile(rtexture_t *rt, const char *filename, qboolean skipuncompressed, qboolean hasalpha)
{
gltexture_t *glt = (gltexture_t *)rt;
case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT: ddsfourcc = "DXT3";bytesperblock = 16;break;
case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT: ddsfourcc = "DXT5";bytesperblock = 16;break;
}
+ // if premultiplied alpha, say so in the DDS file
+ if(glt->flags & TEXF_RGBMULTIPLYBYALPHA)
+ {
+ switch(internalformat)
+ {
+ case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT: ddsfourcc = "DXT2";break;
+ case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT: ddsfourcc = "DXT4";break;
+ }
+ }
if (!bytesperblock && skipuncompressed)
return -3; // skipped
memset(mipinfo, 0, sizeof(mipinfo));
gltexture_t *glt;
gltexturepool_t *pool = (gltexturepool_t *)rtexturepool;
textypeinfo_t *texinfo;
- int mip, mipwidth, mipheight, mipsize;
+ int mip, mipwidth, mipheight, mipsize, mipsize_total;
unsigned int c;
GLint oldbindtexnum = 0;
- const unsigned char *mippixels, *ddspixels;
+ const unsigned char *mippixels, *ddspixels, *mippixels_start;
unsigned char *dds;
fs_offset_t ddsfilesize;
unsigned int ddssize;
+ qboolean force_swdecode = (r_texture_dds_swdecode.integer > 1);
if (cls.state == ca_dedicated)
return NULL;
}
else if (!memcmp(dds+84, "DXT1", 4))
{
- if(!vid.support.ext_texture_compression_s3tc)
- {
- Mem_Free(dds);
- return NULL;
- }
// we need to find out if this is DXT1 (opaque) or DXT1A (transparent)
// LordHavoc: it is my belief that this does not infringe on the
// patent because it is not decoding pixels...
}
}
}
- else if (!memcmp(dds+84, "DXT3", 4))
+ else if (!memcmp(dds+84, "DXT3", 4) || !memcmp(dds+84, "DXT2", 4))
{
- if(!vid.support.ext_texture_compression_s3tc)
+ if(!memcmp(dds+84, "DXT2", 4))
{
- Mem_Free(dds);
- return NULL;
+ if(!(flags & TEXF_RGBMULTIPLYBYALPHA))
+ {
+ Con_Printf("^1%s: expecting DXT3 image without premultiplied alpha, got DXT2 image with premultiplied alpha\n", filename);
+ }
+ }
+ else
+ {
+ if(flags & TEXF_RGBMULTIPLYBYALPHA)
+ {
+ Con_Printf("^1%s: expecting DXT2 image without premultiplied alpha, got DXT3 image without premultiplied alpha\n", filename);
+ }
}
textype = TEXTYPE_DXT3;
bytesperblock = 16;
}
// we currently always assume alpha
}
- else if (!memcmp(dds+84, "DXT5", 4))
+ else if (!memcmp(dds+84, "DXT5", 4) || !memcmp(dds+84, "DXT4", 4))
{
- if(!vid.support.ext_texture_compression_s3tc)
+ if(!memcmp(dds+84, "DXT4", 4))
{
- Mem_Free(dds);
- return NULL;
+ if(!(flags & TEXF_RGBMULTIPLYBYALPHA))
+ {
+ Con_Printf("^1%s: expecting DXT5 image without premultiplied alpha, got DXT4 image with premultiplied alpha\n", filename);
+ }
+ }
+ else
+ {
+ if(flags & TEXF_RGBMULTIPLYBYALPHA)
+ {
+ Con_Printf("^1%s: expecting DXT4 image without premultiplied alpha, got DXT5 image without premultiplied alpha\n", filename);
+ }
}
textype = TEXTYPE_DXT5;
bytesperblock = 16;
return NULL;
}
+ force_swdecode = false;
+ if(bytesperblock)
+ {
+ if(vid.support.arb_texture_compression && vid.support.ext_texture_compression_s3tc)
+ {
+ if(r_texture_dds_swdecode.integer > 1)
+ force_swdecode = true;
+ }
+ else
+ {
+ if(r_texture_dds_swdecode.integer < 1)
+ {
+ // unsupported
+ Mem_Free(dds);
+ return NULL;
+ }
+ force_swdecode = true;
+ }
+ }
+
// return whether this texture is transparent
if (hasalphaflag)
*hasalphaflag = (flags & TEXF_ALPHA) != 0;
+ // if we SW decode, choose 2 sizes bigger
+ if(force_swdecode)
+ {
+ // this is quarter res, so do not scale down more than we have to
+ miplevel -= 2;
+
+ if(miplevel < 0)
+ Con_DPrintf("WARNING: fake software decoding of compressed texture %s degraded quality\n", filename);
+ }
+
+ // this is where we apply gl_picmip
+ mippixels_start = ddspixels;
+ mipwidth = dds_width;
+ mipheight = dds_height;
+ while(miplevel >= 1 && dds_miplevels >= 1)
+ {
+ if (mipwidth <= 1 && mipheight <= 1)
+ break;
+ mipsize = bytesperblock ? ((mipwidth+3)/4)*((mipheight+3)/4)*bytesperblock : mipwidth*mipheight*bytesperpixel;
+ mippixels_start += mipsize; // just skip
+ --dds_miplevels;
+ --miplevel;
+ if (mipwidth > 1)
+ mipwidth >>= 1;
+ if (mipheight > 1)
+ mipheight >>= 1;
+ }
+ mipsize_total = ddssize - 128 - (mippixels_start - ddspixels);
+ mipsize = bytesperblock ? ((mipwidth+3)/4)*((mipheight+3)/4)*bytesperblock : mipwidth*mipheight*bytesperpixel;
+
+ // from here on, we do not need the ddspixels and ddssize any more (apart from the statistics entry in glt)
+
+ // fake decode S3TC if needed
+ if(force_swdecode)
+ {
+ int mipsize_new = mipsize_total / bytesperblock * 4;
+ unsigned char *mipnewpixels = (unsigned char *) Mem_Alloc(tempmempool, mipsize_new);
+ unsigned char *p = mipnewpixels;
+ for (i = bytesperblock == 16 ? 8 : 0;i < (int)mipsize_total;i += bytesperblock, p += 4)
+ {
+ c = mippixels_start[i] + 256*mippixels_start[i+1] + 65536*mippixels_start[i+2] + 16777216*mippixels_start[i+3];
+ p[2] = (((c >> 11) & 0x1F) + ((c >> 27) & 0x1F)) * (0.5f / 31.0f * 255.0f);
+ p[1] = (((c >> 5) & 0x3F) + ((c >> 21) & 0x3F)) * (0.5f / 63.0f * 255.0f);
+ p[0] = (((c ) & 0x1F) + ((c >> 16) & 0x1F)) * (0.5f / 31.0f * 255.0f);
+ if(textype == TEXTYPE_DXT5)
+ p[3] = (0.5 * mippixels_start[i-8] + 0.5 * mippixels_start[i-7]);
+ else if(textype == TEXTYPE_DXT3)
+ p[3] = (
+ (mippixels_start[i-8] & 0x0F)
+ + (mippixels_start[i-8] >> 4)
+ + (mippixels_start[i-7] & 0x0F)
+ + (mippixels_start[i-7] >> 4)
+ + (mippixels_start[i-6] & 0x0F)
+ + (mippixels_start[i-6] >> 4)
+ + (mippixels_start[i-5] & 0x0F)
+ + (mippixels_start[i-5] >> 4)
+ ) * (0.125f / 15.0f * 255.0f);
+ else
+ p[3] = 255;
+ }
+
+ textype = TEXTYPE_BGRA;
+ bytesperblock = 0;
+ bytesperpixel = 4;
+
+ // as each block becomes a pixel, we must use pixel count for this
+ mipwidth = (mipwidth + 3) / 4;
+ mipheight = (mipheight + 3) / 4;
+ mipsize = bytesperpixel * mipwidth * mipheight;
+ mippixels_start = mipnewpixels;
+ mipsize_total = mipsize_new;
+ }
+
+ // start mip counting
+ mippixels = mippixels_start;
+
// calculate average color if requested
if (avgcolor)
{
Vector4Clear(avgcolor);
if (bytesperblock)
{
- for (i = bytesperblock == 16 ? 8 : 0;i < size;i += bytesperblock)
+ for (i = bytesperblock == 16 ? 8 : 0;i < mipsize;i += bytesperblock)
{
- c = ddspixels[i] + 256*ddspixels[i+1] + 65536*ddspixels[i+2] + 16777216*ddspixels[i+3];
+ c = mippixels[i] + 256*mippixels[i+1] + 65536*mippixels[i+2] + 16777216*mippixels[i+3];
avgcolor[0] += ((c >> 11) & 0x1F) + ((c >> 27) & 0x1F);
avgcolor[1] += ((c >> 5) & 0x3F) + ((c >> 21) & 0x3F);
avgcolor[2] += ((c ) & 0x1F) + ((c >> 16) & 0x1F);
+ if(textype == TEXTYPE_DXT5)
+ avgcolor[3] += (0.5 * mippixels[i-8] + 0.5 * mippixels[i-7]);
+ else if(textype == TEXTYPE_DXT3)
+ avgcolor[3] += (
+ (mippixels_start[i-8] & 0x0F)
+ + (mippixels_start[i-8] >> 4)
+ + (mippixels_start[i-7] & 0x0F)
+ + (mippixels_start[i-7] >> 4)
+ + (mippixels_start[i-6] & 0x0F)
+ + (mippixels_start[i-6] >> 4)
+ + (mippixels_start[i-5] & 0x0F)
+ + (mippixels_start[i-5] >> 4)
+ ) * (0.125f / 15.0f * 255.0f);
+ else
+ avgcolor[3] += 255;
}
f = (float)bytesperblock / size;
avgcolor[0] *= (0.5f / 31.0f) * f;
avgcolor[1] *= (0.5f / 63.0f) * f;
avgcolor[2] *= (0.5f / 31.0f) * f;
- avgcolor[3] = 1; // too hard to calculate
+ avgcolor[3] *= f;
}
else
{
- for (i = 0;i < size;i += 4)
+ for (i = 0;i < mipsize;i += 4)
{
- avgcolor[0] += ddspixels[i+2];
- avgcolor[1] += ddspixels[i+1];
- avgcolor[2] += ddspixels[i];
- avgcolor[3] += ddspixels[i+3];
+ avgcolor[0] += mippixels[i+2];
+ avgcolor[1] += mippixels[i+1];
+ avgcolor[2] += mippixels[i];
+ avgcolor[3] += mippixels[i+3];
}
f = (1.0f / 255.0f) * bytesperpixel / size;
avgcolor[0] *= f;
}
}
- // this is where we apply gl_picmip
- mippixels = ddspixels;
- mipwidth = dds_width;
- mipheight = dds_height;
- while(miplevel >= 1 && dds_miplevels >= 1)
- {
- if (mipwidth <= 1 && mipheight <= 1)
- break;
- mipsize = bytesperblock ? ((mipwidth+3)/4)*((mipheight+3)/4)*bytesperblock : mipwidth*mipheight*bytesperpixel;
- mippixels += mipsize; // just skip
- --dds_miplevels;
- --miplevel;
- if (mipwidth > 1)
- mipwidth >>= 1;
- if (mipheight > 1)
- mipheight >>= 1;
- }
-
// when not requesting mipmaps, do not load them
if(!(flags & TEXF_MIPMAP))
dds_miplevels = 0;
else
flags &= ~TEXF_MIPMAP;
- // if S3TC is not supported, there's very little we can do about it
- if (bytesperblock && !vid.support.ext_texture_compression_s3tc)
- {
- Mem_Free(dds);
- Con_Printf("^1%s: DDS file is compressed but OpenGL driver does not support S3TC\n", filename);
- return NULL;
- }
-
texinfo = R_GetTexTypeInfo(textype, flags);
glt = (gltexture_t *)Mem_ExpandableArray_AllocRecord(&texturearray);
for (mip = 0;mip <= dds_miplevels;mip++) // <= to include the not-counted "largest" miplevel
{
mipsize = bytesperblock ? ((mipwidth+3)/4)*((mipheight+3)/4)*bytesperblock : mipwidth*mipheight*bytesperpixel;
- if (mippixels + mipsize > dds + ddssize)
+ if (mippixels + mipsize > mippixels_start + mipsize_total)
break;
switch(vid.renderpath)
{
}
Mem_Free(dds);
+ if(force_swdecode)
+ Mem_Free((unsigned char *) mippixels_start);
return (rtexture_t *)glt;
}
projects / xonotic / darkplaces.git / blobdiff