working generator

src/args.c

@@ -16,7 +16,8 @@ void print_help(int status_code) {
        "[-p=PIXEL_SIZE] "
        "[-s=SLOPE] "
        "[-c=R,G,B] "
-       "[-v=R,G,B]\n\n"
+       "[-v=R,G,B] "
+       "[-m]\n\n"
        "generates a marble-like pattern bitmap image.\n\n"
        "options:\n"
        "  --help             show this help message and exit\n"
@@ -29,7 +30,8 @@ void print_help(int status_code) {
        "  -s, --slope        slope [0-255] (default: random)\n"
        "  -c, --color        base color [0-255,0-255,0-255] (default: random)\n"
        "  -v, --variation    base variation [0-255,0-255,0-255] (default: "
-       "random)");
+       "random)"
+       "  -m, --monochrome   black & white generation");
   exit(status_code);
 }
 
@@ -119,6 +121,7 @@ parameters parse_args(int argc, char **argv) {
   params.width = 0;
   params.height = 0;
   params.file_path = "output.bmp";
+  params.monochrome = false;
 
   bool size_set = false;
   bool slope_set = false;
@@ -170,6 +173,8 @@ parameters parse_args(int argc, char **argv) {
     } else if (is_arg(arg, "-v") || is_arg(arg, "--variation")) {
       parse_color(arg, value, params.var);
       var_set = true;
+    } else if (is_arg(arg, "-m") || is_arg(arg, "--monochrome")) {
+      params.monochrome = true;
     } else {
       invalid_arg(arg);
     }

src/generator.c

@@ -5,10 +5,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-#define COLOR_DEPTH 3
-
 parameters global_params;
-float global_fslope;
+float slope;
+unsigned char color_depth;
 unsigned int line_width;
 unsigned char *last_line;
 unsigned char *current_line;
@@ -17,8 +16,8 @@ unsigned char generate_pixel(unsigned char depth, unsigned char top_pixel,
                              unsigned char left_pixel) {
   float v = fminf(
       255.0, fmaxf(0.0, (rand_float(2.0) - 1.0) * global_params.var[depth] +
-                            ((float)left_pixel) * global_fslope +
+                            ((float)left_pixel) * slope +
-                            ((float)top_pixel) * (1.0 - global_fslope)));
+                            ((float)top_pixel) * (1.0 - slope)));
   return (unsigned char)v;
 }
 
@@ -28,12 +27,12 @@ void generate_line() {
     last_line[i] = current_line[i];
   }
   for (i = 0; i < line_width; i++) {
-    if (i < COLOR_DEPTH) {
+    if (i < color_depth) {
-      current_line[i] = generate_pixel(i % COLOR_DEPTH, last_line[i],
+      current_line[i] = generate_pixel(i % color_depth, last_line[i],
-                                       global_params.start[i % COLOR_DEPTH]);
+                                       global_params.start[i % color_depth]);
     } else {
-      current_line[i] = generate_pixel(i % COLOR_DEPTH, last_line[i],
+      current_line[i] = generate_pixel(i % color_depth, last_line[i],
-                                       current_line[i - COLOR_DEPTH]);
+                                       current_line[i - color_depth]);
     }
   }
 }
@@ -42,12 +41,12 @@ void generate_bmp_line(unsigned short y, unsigned char *data_buffer,
                        unsigned int len) {
   unsigned int i;
   unsigned int x;
-  for (i = 0; i < len; i++) {
+  if (y > 0 && (y % global_params.size) == 0) {
-    if (y > 0 && y % global_params.size == 0) {
     generate_line();
   }
-    x = i / (COLOR_DEPTH * global_params.size);
+  for (i = 0; i < len; i++) {
-    data_buffer[i] = current_line[x * COLOR_DEPTH + (i % COLOR_DEPTH)];
+    x = i / (color_depth * global_params.size);
+    data_buffer[i] = current_line[x * color_depth + (i % color_depth)];
   }
 }
 
@@ -58,22 +57,28 @@ void debug_parameters(parameters params) {
     printf("width   %d\n", params.width);
     printf("height  %d\n", params.height);
     printf("pixel   %d\n", params.size);
+    if (params.monochrome) {
+      printf("color   %u\n", params.start[0]);
+      printf("var.    %u\n", params.var[0]);
+    } else {
       printf("color   %u,%u,%u\n", params.start[0], params.start[1],
              params.start[2]);
       printf("var.    %u,%u,%u\n", params.var[0], params.var[1], params.var[2]);
     }
   }
+}
 
 void init(parameters params) {
   global_params = params;
-  global_fslope = ((float)params.slope) / 255.0;
+  slope = ((float)params.slope) / 255.0;
+  color_depth = params.monochrome ? 1 : 3;
   debug_parameters(params);
-  line_width = ((params.width / params.size) + 1) * COLOR_DEPTH;
+  line_width = ((params.width / params.size) + 1) * color_depth;
   last_line = (unsigned char *)malloc(line_width);
   current_line = (unsigned char *)malloc(line_width);
   unsigned int i = 0;
   for (i = 0; i < line_width; i++) {
-    current_line[i] = params.start[i % COLOR_DEPTH];
+    current_line[i] = params.start[i % color_depth];
   }
   set_seed(params.seed);
   generate_line();
@@ -86,7 +91,7 @@ void clean() {
 
 void generate(parameters params) {
   init(params);
-  bmp_generate(params.width, params.height, COLOR_DEPTH, params.file_path,
+  bmp_generate(params.width, params.height, color_depth, params.file_path,
                generate_bmp_line);
   clean();
 }

src/types.h

@@ -5,6 +5,7 @@
 
 struct Parameters {
   bool quiet;
+  bool monochrome;
   unsigned long seed;
   unsigned short width;
   unsigned short height;