Beginning of a libwmf wrapper

src/calibre/utils/wmf/__init__.py

@@ -0,0 +1,9 @@
+#!/usr/bin/env python
+# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+
+__license__   = 'GPL v3'
+__copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
+__docformat__ = 'restructuredtext en'
+
+
+

src/calibre/utils/wmf/wmf.c

@@ -0,0 +1,200 @@
+#define UNICODE
+#define PY_SSIZE_T_CLEAN
+#include <Python.h>
+
+#include <libwmf/api.h>
+#include <libwmf/svg.h>
+
+typedef struct {
+    char *data;
+    size_t len;
+    size_t pos;
+} buf;
+
+//This code is taken mostly from the Abiword wmf plugin
+
+
+// returns unsigned char cast to int, or EOF
+static int wmf_WMF_read(void * context) {
+    char c;
+	buf *info = (buf*)context;
+
+	if (info->pos == info->len)
+		return EOF;
+
+	c = info->data[pos];
+
+	info->pos++;
+
+	return (int)c;
+}
+
+// returns (-1) on error, else 0
+static int wmf_WMF_seek(void * context, long pos) {
+	buf* info = (buf*) context;
+
+    if (pos < 0 || (size_t)pos > info->len) return -1;
+	info->pos = (size_t)pos;
+	return 0;
+}
+
+// returns (-1) on error, else pos
+static long wmf_WMF_tell(void * context) {
+	buf* info = (buf*) context;
+
+	return (long) info->pos;
+}
+
+
+#define CLEANUP if(API) { if (stream) wmf_free(API, stream); wmf_api_destroy(API); };
+
+static PyObject *
+wmf_render(PyObject *self, PyObject *args) {
+    char *data;
+    Py_ssize_t sz;
+    PyObject *ans;
+
+	unsigned int disp_width  = 0;
+	unsigned int disp_height = 0;
+
+	float wmf_width;
+	float wmf_height;
+	float ratio_wmf;
+	float ratio_bounds;
+
+	unsigned long flags;
+
+	unsigned int max_width  = 1600;
+	unsigned int max_height = 1200;
+	unsigned long max_flags = 0;
+
+	static const char* Default_Description = "wmf2svg";
+
+	wmf_error_t err;
+
+	wmf_svg_t* ddata = 0;
+
+	wmfAPI* API = 0;
+	wmfD_Rect bbox;
+
+	wmfAPI_Options api_options;
+
+    buf read_info;
+
+	char *stream = NULL;
+	unsigned long stream_len = 0;
+
+    if (!PyArg_ParseTuple(args, "s#", &data, &sz))
+        return NULL;
+
+	flags = WMF_OPT_IGNORE_NONFATAL | WMF_OPT_FUNCTION;
+	api_options.function = wmf_svg_function;
+
+	err = wmf_api_create(&API, flags, &api_options);
+
+	if (err != wmf_E_None) {
+        CLEANUP;
+        return PyErr_NoMemory();
+	}
+
+	read_info.data = data;
+	read_info.len = sz;
+	read_info.pos = 0;
+
+	err = wmf_bbuf_input(API, wmf_WMF_read, wmf_WMF_seek, wmf_WMF_tell, (void *) &read_info);
+	if (err != wmf_E_None) {
+        CLEANUP;
+        PyErr_SetString(PyExc_Exception, "Failed to initialize WMF input");
+        return NULL;
+	}
+
+	err = wmf_scan(API, 0, &(bbox));
+	if (err != wmf_E_None)
+	{	
+        CLEANUP;
+        PyErr_SetString(PyExc_ValueError, "Failed to scan the WMF");
+        return NULL;
+	}
+
+/* Okay, got this far, everything seems cool.
+ */
+	ddata = WMF_SVG_GetData (API);
+
+	ddata->out = wmf_stream_create(API, NULL);
+
+	ddata->Description = (char *)Default_Description;
+
+	ddata->bbox = bbox;
+
+	wmf_display_size(API, &disp_width, &disp_height, 96, 96);
+
+	wmf_width  = (float) disp_width;
+	wmf_height = (float) disp_height;
+
+	if ((wmf_width <= 0) || (wmf_height <= 0)) {
+        CLEANUP;
+        PyErr_SetString(PyExc_ValueError, "Bad WMF image size");
+        return NULL;
+	}
+
+	if ((wmf_width  > (float) max_width )
+	 || (wmf_height > (float) max_height)) {
+		ratio_wmf = wmf_height / wmf_width;
+		ratio_bounds = (float) max_height / (float) max_width;
+
+		if (ratio_wmf > ratio_bounds) {
+			ddata->height = max_height;
+			ddata->width  = (unsigned int) ((float) ddata->height / ratio_wmf);
+		}
+		else {
+			ddata->width  = max_width;
+			ddata->height = (unsigned int) ((float) ddata->width  * ratio_wmf);
+		}
+	}
+	else {
+		ddata->width  = (unsigned int) ceil ((double) wmf_width );
+		ddata->height = (unsigned int) ceil ((double) wmf_height);
+	}
+
+	ddata->flags |= WMF_SVG_INLINE_IMAGES;
+
+	ddata->flags |= WMF_GD_OUTPUT_MEMORY | WMF_GD_OWN_BUFFER;
+
+    err = wmf_play(API, 0, &(bbox));
+
+    if (err != wmf_E_None) {
+        CLEANUP;
+        PyErr_SetString(PyExc_ValueError, "Playing of the WMF file failed");
+        return NULL;
+    }
+
+	wmf_stream_destroy(API, ddata->out, &stream, &stream_len);
+
+    ans = Py_BuildValue("s#", stream, stream_len);
+    
+    wmf_free(API, stream);
+    wmf_api_destroy (API);
+
+    return ans;
+}
+
+
+static PyMethodDef wmf_methods[] = {
+    {"render", wmf_render, METH_VARARGS,
+        "render(path) -> Render wmf as svg."
+    },
+
+    {NULL}  /* Sentinel */
+};
+
+
+PyMODINIT_FUNC
+initwmf(void) 
+{
+    PyObject* m;
+    m = Py_InitModule3("wmf", wmf_methods,
+                       "Wrapper for the libwmf library");
+
+
+}
+