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authorTavian Barnes <tavianator@tavianator.com>2014-05-16 17:50:57 -0400
committerTavian Barnes <tavianator@tavianator.com>2014-05-16 17:50:57 -0400
commit1687c00b1642d1e2fe3fbfe4eedf93123e1d6804 (patch)
tree97543919ae97a097658ff525597740d0e86ab6a7 /main.c
parent9dbdaeafa0a9f72ff2d55aa5cafbed664861f8a3 (diff)
downloadkd-forest-1687c00b1642d1e2fe3fbfe4eedf93123e1d6804.tar.xz
Refactor main.c to take configuration on the command line instead of #defines.
Diffstat (limited to 'main.c')
-rw-r--r--main.c496
1 files changed, 357 insertions, 139 deletions
diff --git a/main.c b/main.c
index b78ddf7..ca13889 100644
--- a/main.c
+++ b/main.c
@@ -16,6 +16,7 @@
#include <math.h>
#include <png.h>
#include <setjmp.h>
+#include <stdarg.h>
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
@@ -24,21 +25,214 @@
# include <unistd.h>
#endif
-// Number of trailing zero bits on each color chanel, set to zero for all
-// 24-bit images
-#define BIT_DEPTH 24
-// Whether to sort by hue
-#define HUE_SORT true
+// Possible generation modes
+typedef enum {
+ MODE_HUE_SORT,
+ MODE_RANDOM,
+} mode_t;
+
+// Possible color spaces
+typedef enum {
+ COLOR_SPACE_RGB,
+ COLOR_SPACE_LAB,
+ COLOR_SPACE_LUV,
+} color_space_t;
+
+// Command-line options
+typedef struct {
+ unsigned int bit_depth;
+ mode_t mode;
+ color_space_t color_space;
+ const char *filename;
+ bool help;
+} options_t;
+
+static bool parse_options(options_t *options, int argc, char *argv[]);
+static void print_usage(FILE *file, const char *command);
+
+// All-encompasing state struct
+typedef struct {
+ const options_t *options;
+ unsigned int width;
+ unsigned int height;
+ size_t size;
+ uint32_t *colors;
+ png_byte **bitmap;
+} state_t;
+
+static void init_state(state_t *state, const options_t *options);
+static void generate_image(const state_t *state);
+static void destroy_state(state_t *state);
+
+// Entry point
+int
+main(int argc, char *argv[])
+{
+ options_t options;
+ if (!parse_options(&options, argc, argv)) {
+ fprintf(stderr, "\n");
+ print_usage(stderr, argv[0]);
+ return EXIT_FAILURE;
+ }
+
+ if (options.help) {
+ print_usage(stdout, argv[0]);
+ return EXIT_SUCCESS;
+ }
+
+ // For consistent images
+ srand(0);
+
+ state_t state;
+ init_state(&state, &options);
+ generate_image(&state);
+ destroy_state(&state);
+ return EXIT_SUCCESS;
+}
+
+static bool
+parse_arg(int argc, char *argv[],
+ const char *short_form, const char *long_form,
+ const char **value, int *i, bool *error)
+{
+ size_t short_len = strlen(short_form);
+ size_t long_len = strlen(long_form);
+
+ const char *actual_form;
+ const char *arg = argv[*i];
+ const char *candidate = NULL;
+
+ if (strncmp(arg, short_form, short_len) == 0) {
+ actual_form = short_form;
+ if (strlen(arg) > short_len) {
+ candidate = arg + short_len;
+ }
+ } else if (strncmp(arg, long_form, long_len) == 0) {
+ actual_form = long_form;
+ if (strlen(arg) > long_len) {
+ if (arg[long_len] == '=') {
+ candidate = arg + long_len + 1;
+ } else {
+ return false;
+ }
+ }
+ } else {
+ return false;
+ }
+
+ if (value) {
+ if (candidate) {
+ *value = candidate;
+ } else if (*i < argc - 1) {
+ ++*i;
+ *value = argv[*i];
+ } else {
+ fprintf(stderr, "Expected a value for %s\n", arg);
+ *error = true;
+ return false;
+ }
+ } else if (candidate) {
+ fprintf(stderr, "Unexpected value for %s: `%s'\n",
+ actual_form, candidate);
+ *error = true;
+ return false;
+ }
+
+ return true;
+}
+
+static bool
+str_to_uint(const char *str, unsigned int *value)
+{
+ char *endptr;
+ long result = strtol(str, &endptr, 10);
+ if (*str == '\0' || *endptr != '\0') {
+ return false;
+ }
+ if (result < 0 || result > UINT_MAX) {
+ return false;
+ }
+
+ *value = result;
+ return true;
+}
+
+static void
+print_usage(FILE *file, const char *command)
+{
+ size_t length = strlen(command);
+ char whitespace[length];
+ memset(whitespace, ' ', length);
+
+ fprintf(file, "Usage:\n");
+ fprintf(file, " $ %s [-b|--bit-depth DEPTH]\n", command);
+ fprintf(file, " %s [-s|--hue-sort] [-r|--random]\n", whitespace);
+ fprintf(file, " %s [-c|--color-space RGB|Lab|Luv]\n", whitespace);
+ fprintf(file, " %s [-o|--output PATH]\n", whitespace);
+ fprintf(file, " %s [-h|--help]\n", whitespace);
+ fprintf(file, "\n");
+ fprintf(file, " -b, --bit-depth DEPTH: Use all DEPTH-bit colors (default: 24)\n");
+ fprintf(file, " -s, --hue-sort: Sort colors by hue first (default)\n");
+ fprintf(file, " -r, --random: Randomize colors first\n");
+ fprintf(file, " -c, --color-space RGB|Lab|Luv:\n");
+ fprintf(file, " Use the given color space (default: Lab)\n");
+ fprintf(file, " -o, --output PATH: Output a PNG file at PATH (default: kd-forest.png)\n");
+ fprintf(file, " -h, --help: Show this message\n");
+}
+
+static bool
+parse_options(options_t *options, int argc, char *argv[])
+{
+ // Set defaults
+ options->bit_depth = 24;
+ options->mode = MODE_HUE_SORT;
+ options->color_space = COLOR_SPACE_LAB;
+ options->filename = "kd-forest.png";
+ options->help = false;
+
+ bool result = true;
+
+ for (int i = 1; i < argc; ++i) {
+ const char *value;
+ bool error = false;
+
+ if (parse_arg(argc, argv, "-b", "--bit-depth", &value, &i, &error)) {
+ if (!str_to_uint(value, &options->bit_depth)
+ || options->bit_depth <= 0
+ || options->bit_depth > 24) {
+ fprintf(stderr, "Invalid bit depth: `%s'\n", value);
+ error = true;
+ }
+ } else if (parse_arg(argc, argv, "-s", "--hue-sort", NULL, &i, &error)) {
+ options->mode = MODE_HUE_SORT;
+ } else if (parse_arg(argc, argv, "-r", "--random", NULL, &i, &error)) {
+ options->mode = MODE_RANDOM;
+ } else if (parse_arg(argc, argv, "-o", "--output", &value, &i, &error)) {
+ options->filename = value;
+ } else if (parse_arg(argc, argv, "-c", "--color-space", &value, &i, &error)) {
+ if (strcmp(value, "RGB") == 0) {
+ options->color_space = COLOR_SPACE_RGB;
+ } else if (strcmp(value, "Lab") == 0) {
+ options->color_space = COLOR_SPACE_LAB;
+ } else if (strcmp(value, "Luv") == 0) {
+ options->color_space = COLOR_SPACE_LUV;
+ } else {
+ fprintf(stderr, "Invalid color space: `%s'\n", value);
+ }
+ } else if (parse_arg(argc, argv, "-h", "--help", NULL, &i, &error)) {
+ options->help = true;
+ } else if (!error) {
+ fprintf(stderr, "Unexpected argument `%s'\n", argv[i]);
+ error = true;
+ }
-// Which color space to use
-#define USE_RGB false
-#define USE_LAB true
-#define USE_LUV false
+ if (error) {
+ result = false;
+ }
+ }
-// Computed constants
-static const unsigned int WIDTH = 1U << (BIT_DEPTH + 1)/2; // Round up
-static const unsigned int HEIGHT = 1U << (BIT_DEPTH)/2; // Round down
-static const unsigned int SIZE = 1U << BIT_DEPTH;
+ return result;
+}
static unsigned int
rand_in(unsigned int range)
@@ -52,20 +246,105 @@ rand_in(unsigned int range)
return res%range;
}
+static uint32_t *
+create_colors(const state_t *state)
+{
+ const unsigned int bit_depth = state->options->bit_depth;
+
+ // From least to most perceptually important
+ const unsigned int bskip = 1U << (24 - bit_depth)/3;
+ const unsigned int rskip = 1U << (24 - bit_depth + 1)/3;
+ const unsigned int gskip = 1U << (24 - bit_depth + 2)/3;
+
+ uint32_t *colors = xmalloc(state->size*sizeof(uint32_t));
+ for (unsigned int b = 0, i = 0; b < 0x100; b += bskip) {
+ for (unsigned int g = 0; g < 0x100; g += gskip) {
+ for (unsigned int r = 0; r < 0x100; r += rskip, ++i) {
+ colors[i] = (r << 16) | (g << 8) | b;
+ }
+ }
+ }
+
+ switch (state->options->mode) {
+ case MODE_HUE_SORT:
+ qsort(colors, state->size, sizeof(uint32_t), color_comparator);
+ break;
+
+ case MODE_RANDOM:
+ // Fisher-Yates shuffle
+ for (unsigned int i = state->size; i-- > 0;) {
+ unsigned int j = rand_in(i + 1);
+ uint32_t temp = colors[i];
+ colors[i] = colors[j];
+ colors[j] = temp;
+ }
+ break;
+ }
+
+ return colors;
+}
+
+static png_byte **
+create_bitmap(const state_t *state)
+{
+ png_byte **rows = xmalloc(state->height*sizeof(png_byte *));
+ const size_t row_size = 3*state->width*sizeof(png_byte);
+ for (unsigned int i = 0; i < state->height; ++i) {
+ rows[i] = xmalloc(row_size);
+ memset(rows[i], 0, row_size);
+ }
+ return rows;
+}
+
+static void
+init_state(state_t *state, const options_t *options)
+{
+ state->options = options;
+ state->width = 1U << (options->bit_depth + 1)/2; // Round up
+ state->height = 1U << options->bit_depth/2; // Round down
+ state->size = (size_t)state->width*state->height;
+
+ printf("Generating a %u-bit, %ux%u image (%zu pixels)\n",
+ options->bit_depth, state->width, state->height, state->size);
+
+ state->colors = create_colors(state);
+ state->bitmap = create_bitmap(state);
+}
+
+static void generate_bitmap(const state_t *state);
+static void write_png(const state_t *state, const char *filename);
+
+static void
+generate_image(const state_t *state)
+{
+ generate_bitmap(state);
+ write_png(state, state->options->filename);
+}
+
+static void
+destroy_state(state_t *state)
+{
+ for (unsigned int i = 0; i < state->height; ++i) {
+ free(state->bitmap[i]);
+ }
+ free(state->bitmap);
+ free(state->colors);
+}
+
static kd_node_t *
-try_neighbor(kd_node_t *node, int dx, int dy)
+try_neighbor(const state_t *state, kd_node_t *node, int dx, int dy)
{
if (dx < 0 && node->x < -dx) {
return NULL;
- } else if (dx > 0 && node->x + dx >= WIDTH) {
+ } else if (dx > 0 && node->x + dx >= state->width) {
return NULL;
} else if (dy < 0 && node->y < -dy) {
return NULL;
- } else if (dy > 0 && node->y + dy >= HEIGHT) {
+ } else if (dy > 0 && node->y + dy >= state->height) {
return NULL;
}
- return node + (int)WIDTH*dy + dx;
+ return node + (int)state->width*dy + dx;
}
// Star pattern:
@@ -84,12 +363,12 @@ static int neighbor_order[][2] = {
};
static kd_node_t *
-next_neighbor(kd_node_t *node)
+next_neighbor(const state_t *state, kd_node_t *node)
{
unsigned int first = rand_in(8);
for (unsigned int i = first; i < first + 8; ++i) {
int *delta = neighbor_order[i%8];
- kd_node_t *neighbor = try_neighbor(node, delta[0], delta[1]);
+ kd_node_t *neighbor = try_neighbor(state, node, delta[0], delta[1]);
if (neighbor && !neighbor->added) {
return neighbor;
}
@@ -99,84 +378,61 @@ next_neighbor(kd_node_t *node)
}
static void
-remove_if_surrounded(kd_forest_t *kdf, kd_node_t *node)
+remove_if_surrounded(const state_t *state, kd_forest_t *kdf, kd_node_t *node)
{
- if (node->added && !node->removed && next_neighbor(node) == NULL) {
+ if (node->added && !node->removed && next_neighbor(state, node) == NULL) {
kdf_remove(kdf, node);
}
}
static void
-remove_non_boundary(kd_forest_t *kdf, kd_node_t *node)
+remove_non_boundary(const state_t *state, kd_forest_t *kdf, kd_node_t *node)
{
for (int dy = -1; dy <= 1; ++dy) {
for (int dx = -1; dx <= 1; ++dx) {
- kd_node_t *neighbor = try_neighbor(node, dx, dy);
+ kd_node_t *neighbor = try_neighbor(state, node, dx, dy);
if (neighbor) {
- remove_if_surrounded(kdf, neighbor);
+ remove_if_surrounded(state, kdf, neighbor);
}
}
}
}
-static uint32_t *
-create_colors(void)
+static void
+print_progress(const char *format, ...)
{
- // From least to most perceptually important
- const unsigned int bskip = 1U << (24 - BIT_DEPTH)/3;
- const unsigned int rskip = 1U << (24 - BIT_DEPTH + 1)/3;
- const unsigned int gskip = 1U << (24 - BIT_DEPTH + 2)/3;
-
- uint32_t *colors = xmalloc(SIZE*sizeof(uint32_t));
- for (unsigned int b = 0, i = 0; b < 0x100; b += bskip) {
- for (unsigned int g = 0; g < 0x100; g += gskip) {
- for (unsigned int r = 0; r < 0x100; r += rskip, ++i) {
- colors[i] = (r << 16) | (g << 8) | b;
- }
- }
- }
-
- if (HUE_SORT) {
- qsort(colors, SIZE, sizeof(uint32_t), color_comparator);
- } else {
- // Fisher-Yates shuffle
- for (unsigned int i = SIZE; i-- > 0;) {
- unsigned int j = rand_in(i + 1);
- uint32_t temp = colors[i];
- colors[i] = colors[j];
- colors[j] = temp;
- }
+#if __unix__
+ static bool tty_checked = false;
+ static bool tty = false;
+ if (!tty_checked) {
+ tty = isatty(STDOUT_FILENO);
+ tty_checked = true;
}
+ const char *clear_line = tty ? "\033[2K\r" : "";
+ const char *new_line = tty ? "" : "\n";
+#else
+ const char *clear_line = "";
+ const char *new_line = "\n";
+#endif
- return colors;
-}
+ printf("%s", clear_line);
-static kd_node_t *
-create_kd_nodes(void)
-{
- return xmalloc(SIZE*sizeof(kd_node_t));
-}
+ va_list args;
+ va_start(args, format);
+ vprintf(format, args);
+ va_end(args);
-static png_byte **
-create_bitmap(void)
-{
- png_byte **rows = xmalloc(HEIGHT*sizeof(png_byte *));
- const size_t row_size = 3*WIDTH*sizeof(png_byte);
- for (unsigned int i = 0; i < HEIGHT; ++i) {
- rows[i] = xmalloc(row_size);
- memset(rows[i], 0, row_size);
- }
- return rows;
+ printf("%s", new_line);
+ fflush(stdout);
}
static void
-generate_image(const uint32_t *colors, kd_node_t *nodes,
- unsigned int initial_x, unsigned int initial_y,
- png_byte **bitmap)
+generate_bitmap(const state_t *state)
{
- for (unsigned int y = 0, i = 0; y < HEIGHT; ++y) {
- for (unsigned int x = 0; x < WIDTH; ++x, ++i) {
- kd_node_init(nodes + y*WIDTH + x, x, y);
+ kd_node_t *nodes = xmalloc(state->size*sizeof(kd_node_t));
+ for (unsigned int y = 0, i = 0; y < state->height; ++y) {
+ for (unsigned int x = 0; x < state->width; ++x, ++i) {
+ kd_node_init(nodes + y*state->width + x, x, y);
}
}
@@ -184,71 +440,65 @@ generate_image(const uint32_t *colors, kd_node_t *nodes,
kd_forest_t kdf;
kdf_init(&kdf);
-#if __unix__
- bool tty = isatty(1);
- const char *clear_line = tty ? "\033[2K\r" : "";
- const char *new_line = tty ? "" : "\n";
-#else
- const char *clear_line = "";
- const char *new_line = "\n";
-#endif
-
size_t max_size = 0;
// Do multiple passes to get rid of artifacts in HUE_SORT mode
- for (unsigned int i = 1, progress = 0; i <= BIT_DEPTH; ++i) {
+ unsigned int bit_depth = state->options->bit_depth;
+ for (unsigned int i = 1, progress = 0; i <= bit_depth; ++i) {
unsigned int stripe = 1 << i;
- for (unsigned int j = stripe/2 - 1; j < SIZE; j += stripe, ++progress) {
- if (progress%WIDTH == 0) {
- printf("%s%.2f%%\t| boundary size: %zu\t| max boundary size: %zu%s",
- clear_line, 100.0*progress/SIZE, kdf.size, max_size, new_line);
- fflush(stdout);
+ for (unsigned int j = stripe/2 - 1; j < state->size; j += stripe, ++progress) {
+ if (progress%state->width == 0) {
+ print_progress("%.2f%%\t| boundary size: %zu\t| max boundary size: %zu",
+ 100.0*progress/state->size, kdf.size, max_size);
}
- uint32_t color = colors[j];
+ uint32_t color = state->colors[j];
kd_node_t target;
-#if USE_RGB
- color_set_RGB(target.coords, color);
-#elif USE_LAB
- color_set_Lab(target.coords, color);
-#elif USE_LUV
- color_set_Luv(target.coords, color);
-#else
-# error "Pick one!"
-#endif
+ switch (state->options->color_space) {
+ case COLOR_SPACE_RGB:
+ color_set_RGB(target.coords, color);
+ break;
+ case COLOR_SPACE_LAB:
+ color_set_Lab(target.coords, color);
+ break;
+ case COLOR_SPACE_LUV:
+ color_set_Luv(target.coords, color);
+ break;
+ }
kd_node_t *new_node;
if (j == 0) {
// First node goes in the center
- new_node = nodes + WIDTH*initial_y + initial_x;
+ new_node = nodes + state->size/2 + state->width/2;
} else {
kd_node_t *nearest = kdf_find_nearest(&kdf, &target);
- new_node = next_neighbor(nearest);
+ new_node = next_neighbor(state, nearest);
}
memcpy(new_node->coords, target.coords, sizeof(target.coords));
kdf_insert(&kdf, new_node);
- remove_non_boundary(&kdf, new_node);
+ remove_non_boundary(state, &kdf, new_node);
if (kdf.size > max_size) {
max_size = kdf.size;
}
- png_byte *pixel = bitmap[new_node->y] + 3*new_node->x;
+ png_byte *pixel = state->bitmap[new_node->y] + 3*new_node->x;
color_unpack(pixel, color);
}
}
- printf("%s%.2f%%\t| boundary size: 0\t| max boundary size: %zu\n",
- clear_line, 100.0, max_size);
+ print_progress("%.2f%%\t| boundary size: 0\t| max boundary size: %zu\n",
+ 100.0, max_size);
kdf_destroy(&kdf);
+ free(nodes);
}
static void
-write_png(const char *filename, png_byte **bitmap)
+write_png(const state_t *state, const char *filename)
{
FILE *file = fopen(filename, "wb");
if (!file) {
@@ -272,44 +522,12 @@ write_png(const char *filename, png_byte **bitmap)
}
png_init_io(png_ptr, file);
- png_set_IHDR(png_ptr, info_ptr, WIDTH, HEIGHT, 8,
+ png_set_IHDR(png_ptr, info_ptr, state->width, state->height, 8,
PNG_COLOR_TYPE_RGB, PNG_INTERLACE_ADAM7,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, PNG_sRGB_INTENT_ABSOLUTE);
- png_set_rows(png_ptr, info_ptr, bitmap);
+ png_set_rows(png_ptr, info_ptr, state->bitmap);
png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
png_destroy_write_struct(&png_ptr, &info_ptr);
fclose(file);
}
-
-int
-main(void)
-{
- printf("Generating a %ux%u image (%u pixels)\n", WIDTH, HEIGHT, SIZE);
-
- // For consistent images
- srand(0);
-
- // Generate all the colors
- uint32_t *colors = create_colors();
- // Make a pool of potential k-d nodes
- kd_node_t *nodes = create_kd_nodes();
-
- // Allocate the bitmap
- png_byte **bitmap = create_bitmap();
-
- // Generate the image
- generate_image(colors, nodes, WIDTH/2, HEIGHT/2, bitmap);
-
- // Write out the image
- write_png("kd-forest.png", bitmap);
-
- // Clean up
- for (unsigned int i = 0; i < HEIGHT; ++i) {
- free(bitmap[i]);
- }
- free(bitmap);
- free(nodes);
- free(colors);
- return 0;
-}