Add some buffer management routines

libXmd/build.sh

@@ -3,7 +3,7 @@
 . ../scripts/flags.sh
 
 function build() {
-	cc $CFLAGS -shared -o "lib/libXmd.so" *.c || \
+	cc $CFLAGS -Iinclude -shared -o "lib/libXmd.so" src/*.c || \
 	echo "XXX FAIL!"
 }
 

libXmd/include/Xmd/Buffer.h

@@ -0,0 +1,25 @@
+#ifndef _XmdBuffer_h
+#define _XmdBuffer_h
+
+#include <stddef.h>
+
+/* Buffer is a struct that keeps track of a variable length array of data. It
+   is like a piggy bank, you can add stuff to it and then break it to get access
+   to all the things you put in. It is intended to be used for reading in
+   variable length strings and files. */
+typedef struct _XmdBuffer XmdBuffer;
+
+/* XmdBufferNew creates a new buffer with the specified element size. */
+XmdBuffer *XmdBufferNew (size_t element);
+
+/* XmdBufferPush adds a new element to the buffer. */
+void XmdBufferPush (XmdBuffer *buffer, void *element);
+
+/* XmdBufferBreak frees the buffer without freeing its data. Its data is
+   returned and must be freed manually at some point. */
+void *XmdBufferBreak (XmdBuffer *buffer);
+
+/* XmdBufferFree frees the buffer and any data associated with it. */
+void XmdBufferFree (XmdBuffer *buffer);
+
+#endif

libXmd/src/Buffer.c

@@ -0,0 +1,61 @@
+#include <Xmd/Buffer.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define XmdBUFFER_GROWTH_FACTOR 2
+
+struct _XmdBuffer {
+	void * data;
+	size_t element;
+	size_t length;
+	size_t capacity;
+};
+
+static void  XmdBufferResize (XmdBuffer *buffer, size_t length);
+static void  XmdBufferFit    (XmdBuffer *buffer);
+static void *XmdBufferOffset (XmdBuffer *buffer, size_t index);
+
+XmdBuffer *XmdBufferNew (size_t element) {
+	XmdBuffer *buffer = calloc(1, sizeof(XmdBuffer));
+	buffer->element  = element;
+	buffer->capacity = 1;
+	XmdBufferFit(buffer);
+	return buffer;
+}
+
+void XmdBufferResize (XmdBuffer *buffer, size_t length) {
+	buffer->length = length;
+	XmdBufferFit(buffer);
+}
+
+void XmdBufferFit (XmdBuffer *buffer) {
+	if (buffer->length > buffer->capacity) {
+		buffer->capacity *= XmdBUFFER_GROWTH_FACTOR;
+		buffer->data = realloc (
+			buffer->data,
+			buffer->capacity * buffer->element);
+	}
+}
+
+void *XmdBufferOffset (XmdBuffer *buffer, size_t index) {
+	return buffer->data + (index * buffer->element);
+}
+
+void XmdBufferPush (XmdBuffer *buffer, void *element) {
+	XmdBufferResize(buffer, buffer->length + 1);
+	memcpy (
+		XmdBufferOffset(buffer, buffer->length - 1),
+		element,
+		buffer->element);
+}
+
+void *XmdBufferBreak (XmdBuffer *buffer) {
+	void *data = buffer->data;
+	free(buffer);
+	return data;
+}
+
+void XmdBufferFree (XmdBuffer *buffer) {
+	free(buffer->data);
+	free(buffer);
+}

libXmd/src/Icon.c

@@ -0,0 +1,37 @@
+#include <Xmd/Icon.h>
+
+Pixmap _XmdLoadBitmapIcon (Widget widget, unsigned char *bits, int width, int height) {
+	Pixel fg, bg;
+	XtVaGetValues (widget,
+    		XmNforeground, &fg,
+		XmNbackground, &bg, 
+		NULL);
+	return XCreatePixmapFromBitmapData (
+		XtDisplay (widget),
+		RootWindowOfScreen(XtScreen(widget)),
+		(char *)(bits), width, height,
+		fg, bg, DefaultDepthOfScreen(XtScreen(widget)));
+}
+
+Pixmap XmdReadBitmapFile (Widget widget, const char *filename) {
+	Pixel fg, bg;
+	XtVaGetValues (widget,
+    		XmNforeground, &fg,
+		XmNbackground, &bg, 
+		NULL);
+	unsigned int  width, height;
+	unsigned char *data;
+	int           garbage;
+	XReadBitmapFileData (
+		filename,
+		&width, &height,
+		&data,
+		&garbage, &garbage);
+	Pixmap result = XCreatePixmapFromBitmapData (
+		XtDisplay (widget),
+		RootWindowOfScreen(XtScreen(widget)),
+		(char *)(data), width, height,
+		fg, bg, DefaultDepthOfScreen(XtScreen(widget)));
+	XFree(data);
+	return result;
+}