pdiff: Replace CompareArgs class with args_t struct

This gets rid of nearly the last vestiges of C++ from the pdiff code.

test/pdiff/CompareArgs.cpp

@@ -56,12 +56,14 @@ CompareArgs::~CompareArgs()
 
 bool CompareArgs::Parse_Args(int argc, char **argv)
 {
+    int i;
+
     if (argc < 3) {
 	fprintf (stderr, "%s", copyright);
 	fprintf (stderr, "%s", usage);
 	return false;
     }
-    for (int i = 0; i < argc; i++) {
+    for (i = 0; i < argc; i++) {
 	if (i == 1) {
 	    surface_a = cairo_image_surface_create_from_png (argv[1]);
 	    if (cairo_surface_status (surface_a))

test/pdiff/Makefile.am

@@ -8,8 +8,8 @@ libpdiff_la_SOURCES = 		\
 	pdiff.cpp
 
 perceptualdiff_SOURCES =	\
-	CompareArgs.cpp		\
-	CompareArgs.h		\
+	args.cpp		\
+	args.h			\
 	PerceptualDiff.cpp
 
 INCLUDES = -I$(top_srcdir)/src

test/pdiff/PerceptualDiff.cpp

@@ -21,10 +21,10 @@
 #include <math.h>
 #include <string>
 #include "lpyramid.h"
-#include "CompareArgs.h"
+#include "args.h"
 #include "pdiff.h"
 
-static bool Yee_Compare(CompareArgs &args)
+static bool Yee_Compare(args_t *args)
 {
     int width_a, height_a, stride_a;
     unsigned char *data_a, *row_a;
@@ -35,15 +35,15 @@ static bool Yee_Compare(CompareArgs &args)
     unsigned int x, y, dim, pixels_failed;
     bool identical = true;
 
-    width_a = cairo_image_surface_get_width (args.surface_a);
-    height_a = cairo_image_surface_get_height (args.surface_a);
-    stride_a = cairo_image_surface_get_stride (args.surface_a);
-    data_a = cairo_image_surface_get_data (args.surface_a);
+    width_a = cairo_image_surface_get_width (args->surface_a);
+    height_a = cairo_image_surface_get_height (args->surface_a);
+    stride_a = cairo_image_surface_get_stride (args->surface_a);
+    data_a = cairo_image_surface_get_data (args->surface_a);
 
-    width_b = cairo_image_surface_get_width (args.surface_b);
-    height_b = cairo_image_surface_get_height (args.surface_b);
-    stride_b = cairo_image_surface_get_stride (args.surface_b);
-    data_b = cairo_image_surface_get_data (args.surface_b);
+    width_b = cairo_image_surface_get_width (args->surface_b);
+    height_b = cairo_image_surface_get_height (args->surface_b);
+    stride_b = cairo_image_surface_get_stride (args->surface_b);
+    data_b = cairo_image_surface_get_data (args->surface_b);
 
     if ((width_a != width_b) || (height_a != height_b)) {
 	printf ("FAIL: Image dimensions do not match\n");
@@ -70,11 +70,11 @@ static bool Yee_Compare(CompareArgs &args)
 	return true;
     }
 
-    pixels_failed = pdiff_compare (args.surface_a, args.surface_b,
-				   args.Gamma, args.Luminance,
-				   args.FieldOfView);
+    pixels_failed = pdiff_compare (args->surface_a, args->surface_b,
+				   args->Gamma, args->Luminance,
+				   args->FieldOfView);
 
-    if (pixels_failed < args.ThresholdPixels) {
+    if (pixels_failed < args->ThresholdPixels) {
 	printf ("PASS: Images are perceptually indistinguishable\n");
 	return true;
     }
@@ -87,12 +87,15 @@ static bool Yee_Compare(CompareArgs &args)
 
 int main(int argc, char **argv)
 {
-    CompareArgs args;
+    args_t args;
 
-    if (!args.Parse_Args(argc, argv)) {
+    args_init (&args);
+
+    if (!args_parse (&args, argc, argv)) {
 	return -1;
     } else {
-	if (args.Verbose) args.Print_Args();
+	if (args.Verbose)
+	    args_print (&args);
     }
-    return ! Yee_Compare(args);
+    return ! Yee_Compare(&args);
 }

test/pdiff/args.cpp

@@ -0,0 +1,118 @@
+/*
+  Comapre Args
+  Copyright (C) 2006 Yangli Hector Yee
+
+  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 2 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include "args.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static const char* copyright =
+"PerceptualDiff version 1.0, Copyright (C) 2006 Yangli Hector Yee\n\
+PerceptualDiff comes with ABSOLUTELY NO WARRANTY;\n\
+This is free software, and you are welcome\n\
+to redistribute it under certain conditions;\n\
+See the GPL page for details: http://www.gnu.org/copyleft/gpl.html\n\n";
+
+static const char *usage =
+"PeceptualDiff image1.tif image2.tif\n\n\
+   Compares image1.tif and image2.tif using a perceptually based image metric\n\
+   Options:\n\
+\t-verbose       : Turns on verbose mode\n\
+\t-fov deg       : Field of view in degrees (0.1 to 89.9)\n\
+\t-threshold p	 : #pixels p below which differences are ignored\n\
+\t-gamma g       : Value to convert rgb into linear space (default 2.2)\n\
+\t-luminance l   : White luminance (default 100.0 cdm^-2)\n\
+\n\
+\n Note: Input files can also be in the PNG format\
+\n";
+
+void
+args_init (args_t *args)
+{
+    args->surface_a = NULL;
+    args->surface_b = NULL;
+    args->Verbose = false;
+    args->FieldOfView = 45.0f;
+    args->Gamma = 2.2f;
+    args->ThresholdPixels = 100;
+    args->Luminance = 100.0f;
+}
+
+void
+args_fini (args_t *args)
+{
+    cairo_surface_destroy (args->surface_a);
+    cairo_surface_destroy (args->surface_b);
+}
+
+bool
+args_parse (args_t *args, int argc, char **argv)
+{
+    if (argc < 3) {
+	fprintf (stderr, "%s", copyright);
+	fprintf (stderr, "%s", usage);
+	return false;
+    }
+    for (int i = 0; i < argc; i++) {
+	if (i == 1) {
+	    args->surface_a = cairo_image_surface_create_from_png (argv[1]);
+	    if (cairo_surface_status (args->surface_a))
+	    {
+		fprintf (stderr, "FAIL: Cannot open %s: %s\n",
+			 argv[1], cairo_status_to_string (cairo_surface_status (args->surface_a)));
+		return false;
+	    }
+	} else if (i == 2) {
+	    args->surface_b = cairo_image_surface_create_from_png (argv[2]);
+	    if (cairo_surface_status (args->surface_b))
+	    {
+		fprintf (stderr, "FAIL: Cannot open %s: %s\n",
+			 argv[2], cairo_status_to_string (cairo_surface_status (args->surface_b)));
+		return false;
+	    }
+	} else {
+	    if (strstr(argv[i], "-fov")) {
+		if (i + 1 < argc) {
+		    args->FieldOfView = (float) atof(argv[i + 1]);
+		}
+	    } else if (strstr(argv[i], "-verbose")) {
+		args->Verbose = true;
+	    } else 	if (strstr(argv[i], "-threshold")) {
+		if (i + 1 < argc) {
+		    args->ThresholdPixels = atoi(argv[i + 1]);
+		}
+	    } else 	if (strstr(argv[i], "-gamma")) {
+		if (i + 1 < argc) {
+		    args->Gamma = (float) atof(argv[i + 1]);
+		}
+	    }else 	if (strstr(argv[i], "-luminance")) {
+		if (i + 1 < argc) {
+		    args->Luminance = (float) atof(argv[i + 1]);
+		}
+	    }
+	}
+    } /* i */
+    return true;
+}
+
+void
+args_print (args_t *args)
+{
+    printf("Field of view is %f degrees\n", args->FieldOfView);
+    printf("Threshold pixels is %d pixels\n", args->ThresholdPixels);
+    printf("The Gamma is %f\n", args->Gamma);
+    printf("The Display's luminance is %f candela per meter squared\n", args->Luminance);
+}

test/pdiff/args.h

@@ -14,21 +14,14 @@
   if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
 
-#ifndef _COMPAREARGS_H
-#define _COMPAREARGS_H
+#ifndef _ARGS_H
+#define _ARGS_H
 
-#include <string>
 #include <cairo.h>
 
 /* Args to pass into the comparison function */
-class CompareArgs
+typedef struct _args
 {
-public:
-    CompareArgs();
-    ~CompareArgs();
-    bool Parse_Args(int argc, char **argv);
-    void Print_Args();
-
     cairo_surface_t	*surface_a;		/* Image A */
     cairo_surface_t	*surface_b;		/* Image B */
     bool		Verbose;		/* Print lots of text or not */
@@ -36,6 +29,18 @@ public:
     float		Gamma;			/* The gamma to convert to linear color space */
     float		Luminance;		/* the display's luminance */
     unsigned int	ThresholdPixels;	/* How many pixels different to ignore */
-};
+} args_t;
+
+void
+args_init (args_t *args);
+
+void
+args_fini (args_t *args);
+
+bool
+args_parse (args_t *args, int argc, char **argv);
+
+void
+args_print (args_t *args);
 
 #endif