Add PNG connection type and Freetype 2 font rendering to glcd driver. The PNG

image writer is for debugging only. The Freetype font renderer still misses some features (e.g. big numbers, character encoding, non-standard cell size).
2011-11-03 22:09:24 +00:00
parent b1e8fa9fb8
commit 2e2bb53af8
13 changed files with 749 additions and 136 deletions
@@ -0,0 +1,171 @@
+/** \file server/drivers/glcd-png.c
+ * This driver writes the framebuffer content to PNG images as
+ * /tmp/lcdproc######.png.
+ */
+
+/*-
+ * Copyright (c) 2011 Markus Dolze
+ *
+ * This file is released under the GNU General Public License. Refer to the
+ * COPYING file distributed with this package.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <errno.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+
+#include <png.h>
+
+#include "lcd.h"
+#include "report.h"
+#include "glcd-low.h"
+#include "glcd-png.h"
+
+/** Private data for the PNG connection type */
+typedef struct glcd_png_data {
+	unsigned char *backingstore;	/**< backing buffer */
+} CT_png_data;
+
+/**
+ * API: Initialize the connection type driver.
+ * \param drvthis  Pointer to driver structure.
+ * \retval 0       Success.
+ * \retval <0      Error.
+ */
+int
+glcd_png_init(Driver *drvthis)
+{
+	PrivateData *p = (PrivateData *)drvthis->private_data;
+	CT_png_data *ct_data;
+
+	report(RPT_INFO, "GLCD/png: intializing");
+
+	/* Set up connection type low-level functions */
+	p->glcd_functions->blit = glcd_png_blit;
+	p->glcd_functions->close = glcd_png_close;
+
+	/* Allocate memory structures */
+	ct_data = (CT_png_data *) calloc(1, sizeof(CT_png_data));
+	if (ct_data == NULL) {
+		report(RPT_ERR, "GLCD/png: error allocating connection data");
+		return -1;
+	}
+	p->ct_data = ct_data;
+
+	ct_data->backingstore = malloc(FB_BYTES_TOTAL);
+	if (ct_data->backingstore == NULL) {
+		report(RPT_ERR, "GLCD/png: unable to allocate backing store");
+		return -1;
+	}
+	memset(ct_data->backingstore, 0x00, FB_BYTES_TOTAL);
+
+	debug(RPT_DEBUG, "GLCD/png: init() done");
+
+	return 0;
+}
+
+/**
+ * API: Write the framebuffer to the display
+ * \param p  Pointer to glcd driver's private date structure.
+ */
+void
+glcd_png_blit(PrivateData *p)
+{
+	CT_png_data *ct_data = (CT_png_data *) p->ct_data;
+	char filename[256];
+	static int num = 0;
+	int row;
+	FILE *fp;
+	png_structp png_ptr;
+	png_infop info_ptr;
+	png_bytep row_pointer;
+
+	/* Check if framebufer has changed. If not there's nothing to do */
+	if (memcmp(p->framebuf, ct_data->backingstore, FB_BYTES_TOTAL) == 0)
+		return;
+
+	snprintf(filename, sizeof(filename), "/tmp/lcdproc%06d.png", num++);
+	fp = fopen(filename, "wb");
+	if (!fp) {
+		p->glcd_functions->drv_debug(RPT_ERR, "File %s could not be opened for writing", filename);
+		return;
+	}
+
+	/* initialize stuff */
+	png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	if (!png_ptr) {
+		p->glcd_functions->drv_debug(RPT_ERR, "png_create_write_struct failed");
+		fclose(fp);
+		return;
+	}
+
+	info_ptr = png_create_info_struct(png_ptr);
+	if (!info_ptr) {
+		p->glcd_functions->drv_debug(RPT_ERR, "png_create_info_struct failed");
+		png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
+		fclose(fp);
+		return;
+	}
+
+	if (setjmp(png_jmpbuf(png_ptr)))
+		goto err_out;
+
+	png_init_io(png_ptr, fp);
+
+	png_set_IHDR(png_ptr, info_ptr, p->px_width, p->px_height,
+		     1, PNG_COLOR_TYPE_GRAY, PNG_INTERLACE_NONE,
+		     PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+	png_set_invert_mono(png_ptr);
+
+	png_write_info(png_ptr, info_ptr);
+
+	/* Write the image row by row */
+	row_pointer = p->framebuf;
+	for (row = 0; row < p->px_height; row++) {
+		png_write_row(png_ptr, row_pointer);
+		row_pointer += BYTES_PER_LINE;
+	}
+
+	png_write_end(png_ptr, NULL);
+	fclose(fp);
+	fp = NULL;
+	png_destroy_write_struct(&png_ptr, &info_ptr);
+
+	memcpy(ct_data->backingstore, p->framebuf, FB_BYTES_TOTAL);
+
+	return;
+
+err_out:
+	p->glcd_functions->drv_debug(RPT_ERR, "Error writing PNG image");
+	if (fp != NULL)
+		fclose(fp);
+	if (png_ptr != NULL)
+		png_destroy_write_struct(&png_ptr, &info_ptr);
+	return;
+}
+
+/**
+ * API: Release low-level resources.
+ * \param p  Pointer to glcd driver's private date structure.
+ */
+void
+glcd_png_close(PrivateData *p)
+{
+	if (p->ct_data != NULL) {
+		CT_png_data *ct_data = (CT_png_data *) p->ct_data;
+
+		if (ct_data->backingstore != NULL)
+			free(ct_data->backingstore);
+
+		free(p->ct_data);
+		p->ct_data = NULL;
+	}
+}