The fundamentals of the new ctypes interface are working

host/Makefile

@@ -1,6 +1,6 @@
 
-all: main.c font.c font.h color.c color.h gif.h gif.c
-	gcc -shared -std=gnu11 -Wall -lm -o libbdf.so -g -O0 main.c font.c color.c
+all: main.c font.c font.h color.c color.h
+	gcc -shared -fPIC -std=gnu11 -Wall -lm -o libbdf.so -g -O0 main.c font.c color.c
 
 clean:
 	rm libbdf.so

host/font.c

@@ -4,6 +4,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 
 void render_glyph(glyph_t *g, color_t *buf, unsigned int bufwidth, unsigned int offx, unsigned int offy, color_t fg, color_t bg){
 	unsigned int bitmap_row_width = g->width/8;
@@ -30,7 +31,7 @@ glyphtable_t *read_bdf_file(char *filename){
 		goto error;
 	}
 
-	glyphtable_t *glyph_table = read_bdf(fontfile, glyph_table, BLP_SIZE)
+	glyphtable_t *glyph_table = read_bdf(fontfile);
 	if(!glyph_table){
 		fprintf(stderr, "Error reading font file.\n");
 		goto error;
@@ -50,15 +51,16 @@ glyphtable_t *extend_glyphtable(glyphtable_t *glyph_table){
 	size_t newlen = oldlen + (oldlen<MAX_GLYPHTABLE_INCREMENT ? oldlen : MAX_GLYPHTABLE_INCREMENT);
 	if(oldlen == 0)
 		newlen = START_GLYPHTABLE_SIZE;
-	glyph_t *newdata = realloc(glyph_table->data, newlen*sizeof(glyph_t));
+	glyph_t **newdata = realloc(glyph_table->data, newlen*sizeof(glyph_t*));
 	if(!newdata){
 		fprintf(stderr, "Cannot allocate bdf glyph buffer\n");
 		goto error;
 	}
 	glyph_table->data = newdata;
 	// Clear newly allocated memory area
-	memset(glyph_table->data+oldlen, 0, (newlen-oldlen)*sizeof(glyph_t));
+	memset(glyph_table->data+oldlen, 0, (newlen-oldlen)*sizeof(glyph_t*));
 	glyph_table->size = newlen;
+	return glyph_table;
 error:
 	free_glyphtable(glyph_table);
 	return NULL;
@@ -66,7 +68,7 @@ error:
 
 void free_glyphtable(glyphtable_t *glyph_table){
 	if(glyph_table){
-		for(unsigned int i=0; i<glyph_table->length; i++){
+		for(unsigned int i=0; i<glyph_table->size; i++){
 			free(glyph_table->data[i]);
 		}
 		free(glyph_table->data);
@@ -119,13 +121,6 @@ glyphtable_t *read_bdf(FILE *f){
 				fprintf(stderr, "Invalid ENCODING line: %s %s\n", line, args);
 				goto error;
 			}
-			if(encoding > glyph_table->size){
-				glyph_table = extend_glyphtable(glyph_table);
-				if(!glyph_table){
-					fprintf(stderr, "Cannot allocate glyph table.\n");
-					goto error;
-				}
-			}
 
 		}else if(strcmp("BBX", line) == 0){
 			if(!args){
@@ -228,6 +223,15 @@ glyphtable_t *read_bdf(FILE *f){
 				}
 				i++;
 			}
+
+			if(encoding >= glyph_table->size){
+				glyph_table = extend_glyphtable(glyph_table);
+				if(!glyph_table){
+					fprintf(stderr, "Cannot extend glyph table.\n");
+					goto error;
+				}
+			}
+
 			memcpy(glyph_data, &current_glyph, sizeof(glyph_t));
 			glyph_table->data[encoding] = glyph_data;
 

host/font.h

@@ -15,7 +15,7 @@ typedef struct {
 } glyph_t;
 
 typedef struct {
-	glyph_t *t;
+	glyph_t **data;
 	size_t size;
 } glyphtable_t;
 
@@ -25,7 +25,9 @@ typedef struct {
 #define MAX_CSI_ELEMENTS 8
 
 // We could also use some fancy hashtable here, but unifont includes about 57k glyphs so we would hardly save any memory.
-int read_bdf(FILE *f, glyph_t **glyph_table, unsigned int glyph_table_size);
+glyphtable_t *read_bdf(FILE *f);
+
+void free_glyphtable(glyphtable_t *glyph_table);
 
 // Requires buf to point to a buffer at least of size glyph->width*glyph->height.
 void render_glyph(glyph_t *glyph, color_t *buf, unsigned int bufwidth, unsigned int offx, unsigned int offy, color_t fg, color_t bg);

host/main.c

@@ -65,7 +65,7 @@ framebuffer_t *framebuffer_render_text(char *s, glyphtable_t *glyph_table){
 		p += inc;
 
 		if(c > glyph_table->size){
-			fprintf(stderr, "Error rendering string: Codepoint 0x%lx out of valid range (0-%d).\n", (long int)c, glyph_table->size);
+			fprintf(stderr, "Error rendering string: Codepoint 0x%lx out of valid range (0-%ld).\n", (long int)c, glyph_table->size);
 			goto error;
 		}
 

host/main.h

@@ -4,7 +4,7 @@
 #include "color.h"
 #include "font.h"
 
-framebuffer_t *framebuffer_render_text(char *s, glyph_t **glyph_table, unsigned int glyph_table_size);
+framebuffer_t *framebuffer_render_text(char *s, glyphtable_t *glyph_table);
 void console_render_buffer(framebuffer_t *fb);
 
 #endif//__MAIN_H__

host/matelight.py

@@ -0,0 +1,35 @@
+import usb
+import colorsys
+import numpy as np
+import itertools
+
+CRATE_WIDTH = 5
+CRATE_HEIGHT = 4
+CRATES_X = 8
+CRATES_Y = 4
+
+DISPLAY_WIDTH = CRATES_X*CRATE_WIDTH
+DISPLAY_HEIGHT = CRATES_Y*CRATE_HEIGHT
+FRAME_SIZE = CRATE_WIDTH*CRATE_HEIGHT*3
+
+dev = usb.core.find(idVendor=0x1cbe, idProduct=0x0003)
+
+def sendframe(framedata):
+	""" Send a frame to the display
+
+	The argument contains a h * w array of 3-tuples of (r, g, b)-data or 4-tuples of (r, g, b, a)-data where the a
+	channel is ignored.
+	"""
+	def chunks(l, n):
+		for i in xrange(0, len(l), n):
+			yield l[i:i+n]
+
+	for cx, cy in itertools.product(range(DISPLAY_WIDTH), range(DISPLAY_HEIGHT)):
+		data = [ v for x in range(CRATE_WIDTH) for y in range(CRATE_HEIGHT) for v in framedata[cy*CRATE_HEIGHT + y][cx*CRATE_WIDTH + x][:3] ]
+		if len(data) != FRAME_SIZE:
+			raise ValueError('Invalid frame data. Expected {} bytes, got {}.'.format(FRAME_SIZE, len(data)))
+		# Send framebuffer data
+		dev.write(0x01, bytes([0, x, y])+bytes(data))
+	# Send latch command
+	dev.write(0x01, b'\x01')
+

host/server.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python
+
+from ctypes import CDLL, POINTER, c_void_p, Structure, c_uint8, c_size_t, cast
+import numpy as np
+from matelight import sendframe
+
+class COLOR(Structure):
+	_fields_ = ('r', c_uint8), ('g', c_uint8), ('b', c_uint8), ('a', c_uint8)
+
+class FRAMEBUFFER(Structure):
+	_fields_ = ('data', POINTER(COLOR)), ('w', c_size_t), ('h', c_size_t)
+
+bdf = CDLL('./libbdf.so')
+bdf.read_bdf_file.restype = c_void_p
+bdf.framebuffer_render_text.restype = POINTER(FRAMEBUFFER)
+
+unifont = bdf.read_bdf_file('unifont.bdf')
+
+def render_text(text):
+	assert unifont
+	fb = bdf.framebuffer_render_text(str(text), unifont)
+	fbd = fb.contents
+	buf = np.ctypeslib.as_array(cast(fbd.data, POINTER(c_uint8)), shape=(fbd.h, fbd.w, 4))
+	# Set data pointer to NULL before freeing framebuffer struct to prevent free_framebuffer from also freeing the data
+	# buffer that is now used by numpy
+	fb.data = cast(c_void_p(), POINTER(COLOR))
+	bdf.free_framebuffer(fb)
+	return buf
+
+if __name__ == '__main__':
+	sendframe(render_text('test'));
+