Parameterize output filename.

Author: schmonz

Makefile

@@ -21,7 +21,7 @@ check: ${THE_TESTS}
 	${SILENT}./${THE_TESTS}
 
 approval: ${THE_PROGRAM}
-	${SILENT}./${THE_PROGRAM} gd 800 500 100 0.0 0.0 4.0
+	${SILENT}./${THE_PROGRAM} gd pngelbrot.png 800 500 100 0.0 0.0 4.0
 	${SILENT}./${APPROVAL_TESTS} pngelbrot.png
 
 valgrind: ${THE_TESTS}

main.c

@@ -5,20 +5,21 @@
 #include "mandelbrot.h"
 
 static int usage(char *progname) {
-    printf("usage: %s <library> <width> <height> <iterations> <a> <b> <range>\n",
+    printf("usage: %s <library> <filename> <width> <height> <iterations> <a> <b> <range>\n",
             basename(progname));
     return 77;
 }
 
 int main(int argc, char *argv[]) {
-    if (argc == 8) {
+    if (argc == 9) {
         mandelbrot(
                 argv[1],
-                atoi(argv[2]),
+                argv[2],
                 atoi(argv[3]),
                 atoi(argv[4]),
-                atof(argv[5]) + I * atof(argv[6]),
-                atof(argv[7])
+                atoi(argv[5]),
+                atof(argv[6]) + I * atof(argv[7]),
+                atof(argv[8])
         );
     } else {
         return usage(argv[0]);

mandelbrot.c

@@ -11,7 +11,6 @@
 
 #include "mandelbrot.h"
 
-static const char *OUTPUTFILE = "pngelbrot.png";
 static const size_t NUM_COLORS = 5;
 static int rgb_colors[NUM_COLORS][3] = {
     { 255, 255, 255 },
@@ -151,7 +150,7 @@ choose_color(size_t escape, size_t maximum_iterations)
 }
 
 static void
-mandelbrot_cairo(size_t width, size_t height, size_t iterations, complex double center, double range)
+mandelbrot_cairo(const char *outputfile, size_t width, size_t height, size_t iterations, complex double center, double range)
 {
     cairo_surface_t *my_surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24, width, height);
     cairo_t *my_cairo = cairo_create(my_surface);
@@ -176,14 +175,14 @@ mandelbrot_cairo(size_t width, size_t height, size_t iterations, complex double
         }
     }
 
-    cairo_surface_write_to_png(my_surface, OUTPUTFILE);
+    cairo_surface_write_to_png(my_surface, outputfile);
 
     cairo_destroy(my_cairo);
     cairo_surface_destroy(my_surface);
 }
 
 static void
-mandelbrot_gd(size_t width, size_t height, size_t iterations, complex double center, double range)
+mandelbrot_gd(const char *outputfile, size_t width, size_t height, size_t iterations, complex double center, double range)
 {
     gdImagePtr im = gdImageCreate(width, height);
     FILE *pngout;
@@ -203,17 +202,17 @@ mandelbrot_gd(size_t width, size_t height, size_t iterations, complex double cen
         }
     }
 
-    pngout = fopen(OUTPUTFILE, "wb");
+    pngout = fopen(outputfile, "wb");
     gdImagePng(im, pngout);
 
     fclose(pngout);
     gdImageDestroy(im);
 }
 
-void mandelbrot(const char *backend, size_t width, size_t height, size_t iterations, complex double center, double range)
+void mandelbrot(const char *backend, const char *outputfile, size_t width, size_t height, size_t iterations, complex double center, double range)
 {
     if (0 == strcmp("cairo", backend))
-        mandelbrot_cairo(width, height, iterations, center, range);
+        mandelbrot_cairo(outputfile, width, height, iterations, center, range);
     else
-        mandelbrot_gd(width, height, iterations, center, range);
+        mandelbrot_gd(outputfile, width, height, iterations, center, range);
 }

mandelbrot.h

@@ -6,7 +6,7 @@ typedef struct extreme_coordinates {
     complex double upper_right;
 } extremes_t;
 
-void mandelbrot(const char *, size_t, size_t, size_t, complex double, double);
+void mandelbrot(const char *,const char *, size_t, size_t, size_t, complex double, double);
 extremes_t get_extreme_coordinates(size_t, size_t, complex double, double);
 complex double coords_for_pixel(size_t, size_t, complex double, double, size_t, size_t);
 size_t count_escape(complex double, size_t);