added interface to get blitbuffers from JPEG/PNG files

this is supposed to help us in the UI code.

Makefile

@@ -87,7 +87,7 @@ LUALIB := $(LUADIR)/src/liblua.a
 
 all:kpdfview
 
-kpdfview: kpdfview.o einkfb.o pdf.o blitbuffer.o drawcontext.o input.o util.o ft.o lfs.o $(MUPDFLIBS) $(THIRDPARTYLIBS) $(LUALIB) djvu.o $(DJVULIBS) cre.o $(CRENGINELIBS)
+kpdfview: kpdfview.o einkfb.o pdf.o blitbuffer.o drawcontext.o input.o util.o ft.o lfs.o mupdfimg.o $(MUPDFLIBS) $(THIRDPARTYLIBS) $(LUALIB) djvu.o $(DJVULIBS) cre.o $(CRENGINELIBS)
 	$(CC) -lm -ldl -lpthread $(EMU_LDFLAGS) $(DYNAMICLIBSTDCPP) \
 		kpdfview.o \
 		einkfb.o \
@@ -98,6 +98,7 @@ kpdfview: kpdfview.o einkfb.o pdf.o blitbuffer.o drawcontext.o input.o util.o ft
 		util.o \
 		ft.o \
 		lfs.o \
+		mupdfimg.o \
 		$(MUPDFLIBS) \
 		$(THIRDPARTYLIBS) \
 		$(LUALIB) \
@@ -114,7 +115,7 @@ slider_watcher: slider_watcher.c
 ft.o: %.o: %.c
 	$(CC) -c $(KPDFREADER_CFLAGS) -I$(FREETYPEDIR)/include $< -o $@
 
-kpdfview.o pdf.o blitbuffer.o util.o drawcontext.o einkfb.o input.o: %.o: %.c
+kpdfview.o pdf.o blitbuffer.o util.o drawcontext.o einkfb.o input.o mupdfimg.o: %.o: %.c
 	$(CC) -c $(KPDFREADER_CFLAGS) $(EMU_CFLAGS) -I$(LFSDIR)/src $< -o $@
 
 djvu.o: %.o: %.c

image.lua

@@ -0,0 +1,25 @@
+Image = {}
+
+function Image._getFileData(filename)
+	local f = io.open("test.png")
+	local data = f:read("*a")
+	f:close()
+	return data
+end
+
+function Image.fromPNG(filename)
+	local img = mupdfimg.new()
+	img:loadPNGData(Image._getFileData(filename))
+	local bb = img:toBlitBuffer()
+	img:free()
+	return bb
+end
+
+function Image.fromJPEG(filename)
+	local img = mupdfimg.new()
+	img:loadJPEGData(Image._getFileData(filename)(fimgdatailename))
+	local bb = img:toBlitBuffer()
+	img:free()
+	return bb
+end
+

kpdfview.c

@@ -26,6 +26,7 @@
 #include "blitbuffer.h"
 #include "drawcontext.h"
 #include "pdf.h"
+#include "mupdfimg.h"
 #include "djvu.h"
 #include "cre.h"
 #include "einkfb.h"
@@ -59,6 +60,7 @@ int main(int argc, char **argv) {
 		luaopen_input(L);
 		luaopen_util(L);
 		luaopen_ft(L);
+		luaopen_mupdfimg(L);
 
 		luaopen_lfs(L);
 

mupdfimg.c

@@ -0,0 +1,154 @@
+/*
+    KindlePDFViewer: MuPDF abstraction for Lua, only image part
+    Copyright (C) 2012 Hans-Werner Hilse <hilse@web.de>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include <fitz/fitz.h>
+
+#include "blitbuffer.h"
+#include "mupdfimg.h"
+#include <stdio.h>
+#include <stddef.h>
+
+
+typedef struct Image {
+	fz_pixmap *pixmap;
+	fz_context *context;
+} Image;
+
+static int newImage(lua_State *L) {
+	int cache_size = luaL_optint(L, 1, 8 << 20); // 8 MB limit default
+
+	Image *img = (Image*) lua_newuserdata(L, sizeof(Image));
+
+	img->pixmap = NULL;
+
+	luaL_getmetatable(L, "image");
+	lua_setmetatable(L, -2);
+
+	img->context = fz_new_context(NULL, NULL, cache_size);
+
+	return 1;
+}
+
+static int loadPNGData(lua_State *L) {
+	Image *img = (Image*) luaL_checkudata(L, 1, "image");
+	size_t length;
+	unsigned char *data = luaL_checklstring(L, 2, &length);
+	fz_try(img->context) {
+		img->pixmap = fz_load_png(img->context, data, length);
+	}
+	fz_catch(img->context) {
+		return luaL_error(L, "cannot load PNG data");
+	}
+}
+
+static int loadJPEGData(lua_State *L) {
+	Image *img = (Image*) luaL_checkudata(L, 1, "image");
+	size_t length;
+	unsigned char *data = luaL_checklstring(L, 2, &length);
+	fz_try(img->context) {
+		img->pixmap = fz_load_jpeg(img->context, data, length);
+	}
+	fz_catch(img->context) {
+		return luaL_error(L, "cannot open JPEG data");
+	}
+}
+
+static int toBlitBuffer(lua_State *L) {
+	Image *img = (Image*) luaL_checkudata(L, 1, "image");
+	BlitBuffer *bb;
+	int ret;
+	int w, h;
+
+	fz_pixmap *pix;
+
+	if(img->pixmap == NULL) {
+		return luaL_error(L, "no pixmap loaded that we could convert");
+	}
+
+	if(img->pixmap->n == 2) {
+		pix = img->pixmap;
+	} else {
+		fz_try(img->context) {
+			pix = fz_new_pixmap(img->context, fz_device_gray, img->pixmap->w, img->pixmap->h);
+		}
+		fz_catch(img->context) {
+			return luaL_error(L, "can't claim new grayscale fz_pixmap");
+		}
+		fz_convert_pixmap(img->context, img->pixmap, pix);
+	}
+
+	ret = newBlitBufferNative(L, img->pixmap->w, img->pixmap->h, &bb);
+	if(ret != 1) {
+		// TODO (?): fail more gracefully, clean up mem?
+		return ret;
+	}
+
+	uint8_t *bbptr = (uint8_t*)bb->data;
+	uint16_t *pmptr = (uint16_t*)pix->samples;
+	int x, y;
+
+	for(y = 0; y < bb->h; y++) {
+		for(x = 0; x < (bb->w / 2); x++) {
+			bbptr[x] = (((pmptr[x*2 + 1] & 0xF0) >> 4) | (pmptr[x*2] & 0xF0)) ^ 0xFF;
+		}
+		if(bb->w & 1) {
+			bbptr[x] = (pmptr[x*2] & 0xF0) ^ 0xF0;
+		}
+		bbptr += bb->pitch;
+		pmptr += bb->w;
+	}
+
+	if(pix != img->pixmap) {
+		fz_drop_pixmap(img->context, pix);
+	}
+
+	return 1;
+}
+
+static int freeImage(lua_State *L) {
+	Image *img = (Image*) luaL_checkudata(L, 1, "image");
+	if(img->pixmap) {
+		fz_drop_pixmap(img->context, img->pixmap);
+	}
+	fz_free_context(img->context);
+	return 0;
+}
+
+static const struct luaL_Reg mupdfimg_func[] = {
+	{"new", newImage},
+	{NULL, NULL}
+};
+
+static const struct luaL_Reg image_meth[] = {
+	{"loadPNGData", loadPNGData},
+	{"loadJPEGData", loadJPEGData},
+	{"toBlitBuffer", toBlitBuffer},
+	{"free", freeImage},
+	{"__gc", freeImage},
+	{NULL, NULL}
+};
+
+int luaopen_mupdfimg(lua_State *L) {
+	luaL_newmetatable(L, "image");
+	lua_pushstring(L, "__index");
+	lua_pushvalue(L, -2);
+	lua_settable(L, -3);
+	luaL_register(L, NULL, image_meth);
+	lua_pop(L, 1);
+	luaL_register(L, "mupdfimg", mupdfimg_func);
+	return 1;
+}

mupdfimg.h

@@ -0,0 +1,26 @@
+/*
+    KindlePDFViewer: MuPDF abstraction for Lua, only image part
+    Copyright (C) 2012 Hans-Werner Hilse <hilse@web.de>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#ifndef _MUPDFIMG_H
+#define _MUPDFIMG_H
+
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+
+int luaopen_mupdfimg(lua_State *L);
+#endif