ntrop

commit 5b72cec00a5f0c5f8a77dde65271fb90b844f779
parent 32acf8e0eec26560c3025a3a503428b2e5f5c9af
Author: Louis Burda <quent.burda@gmail.com>
Date:   Sun, 12 Feb 2023 15:21:46 +0100

Fix floating point error in zoom division and improve navigation

Diffstat:
M
Makefile
 | 
2
+-
M
ntrop.c
 | 
60
+++++++++++++++++++++++++++++++++++++++---------------------

2 files changed, 40 insertions(+), 22 deletions(-)
diff --git a/Makefile b/Makefile
@@ -1,4 +1,4 @@
-CFLAGS = -Wunused-variable -Wunused-function
+CFLAGS = -Wunused-variable -Wunused-function -g
 LDLIBS = -lraylib -lm
 
 all: ntrop
diff --git a/ntrop.c b/ntrop.c
@@ -24,7 +24,7 @@ Color *entropy_colors;
 
 int entropy_ctx;
 
-double zoom;
+uint64_t zoom;
 double zoom_x, zoom_y;
 
 int window_width;
@@ -39,6 +39,8 @@ int  drag_mouse_x, drag_mouse_y;
 double drag_zoom_x, drag_zoom_y;
 bool drag;
 
+uint64_t hold_times[337] = { 0 };
+
 char fmtbuf[256];
 
 void
@@ -49,12 +51,12 @@ usage(void)
 }
 
 uint8_t *
-readfile(const char *path, size_t *len)
+read_file(const char *path, size_t *len)
 {
 	FILE *file;
 	char *chunk;
 	uint8_t *data;
-	size_t nread;
+	ssize_t nread;
 	size_t cap;
 
 	chunk = malloc(CHUNK_SIZE);
@@ -68,7 +70,7 @@ readfile(const char *path, size_t *len)
 	if (!data) err(1, "malloc");
 
 	*len = 0;
-	while ((nread = fread(chunk, 1, CHUNK_SIZE, file))) {
+	while ((nread = fread(chunk, 1, CHUNK_SIZE, file)) > 0) {
 		if (*len + nread > cap) {
 			cap *= 2;
 			data = realloc(data, cap);
@@ -142,8 +144,8 @@ init_entropy_colors(Color *data_colors)
 		}
 		entropy /= - 1.F * log2(1.F / ctx_count);
 		entropy *= 255;
-		c.r = entropy;
-		c.g = entropy;
+		c.r = file_data[pos];
+		c.g = 0;
 		c.b = entropy;
 		data_colors[pos] = c;
 	}
@@ -152,6 +154,21 @@ init_entropy_colors(Color *data_colors)
 	free(counts);
 }
 
+bool
+key_press_hold(int key)
+{
+	if (!IsKeyDown(key)) {
+		hold_times[key] = 0;
+		return false;
+	}
+
+	if (IsKeyPressed(key))
+		return true;
+	hold_times[key] += 1;
+
+	return hold_times[key] > 10;
+}
+
 void
 vis(void)
 {
@@ -159,7 +176,7 @@ vis(void)
 	Image window_image;
 	size_t pos, len;
 	double mouse_move;
-	size_t data_x, data_y;
+	ssize_t data_x, data_y;
 	size_t data_pos;
 	size_t x, y;
 
@@ -194,10 +211,10 @@ vis(void)
 		if (IsWindowResized()) {
 			window_width = GetScreenWidth();
 			window_height = GetScreenHeight();
-			data_width = MIN(window_width / 2, 400);
+			data_width = MAX(MIN(data_len, MIN(window_width / 2, 400)), 1);
 			data_height = data_len / data_width + !!(data_len % data_width);
-			zoom_x = (data_width - window_width / zoom) / 2.F;
-			zoom_y = (data_height - window_height / zoom) / 2.F;
+			zoom_x = (data_width - 1.F * window_width / zoom) / 2.F;
+			zoom_y = (data_height - 1.F * window_height / zoom) / 2.F;
 			ImageResize(&window_image, window_width, window_height);
 		}
 
@@ -236,21 +253,22 @@ vis(void)
 		show_pos ^= IsKeyPressed(KEY_T);
 
 		if (IsKeyDown(KEY_LEFT_ALT)) {
-			if (IsKeyDown(KEY_LEFT) && data_width > 0)
+			if (key_press_hold(KEY_LEFT) && data_width > 0)
 				data_width -= 1;
-			else if (IsKeyDown(KEY_RIGHT))
+			else if (key_press_hold(KEY_RIGHT))
 				data_width += 1;
 		} else {
-			if (IsKeyDown(KEY_LEFT))
+			if (key_press_hold(KEY_LEFT))
 				zoom_x -= 20.F / zoom;
-			else if (IsKeyDown(KEY_RIGHT))
+			else if (key_press_hold(KEY_RIGHT))
 				zoom_x += 20.F / zoom;
 
-			if (IsKeyDown(KEY_UP))
+			if (key_press_hold(KEY_UP))
 				zoom_y -= 20.F / zoom;
-			else if (IsKeyDown(KEY_DOWN))
+			else if (key_press_hold(KEY_DOWN))
 				zoom_y += 20.F / zoom;
 		}
+		data_height = data_len / data_width + !!(data_len % data_width);
 
 		if (IsKeyPressed(KEY_P)) {
 			show_value = !show_value;
@@ -264,12 +282,12 @@ vis(void)
 		ImageClearBackground(&window_image, BLACK);
 
 		for (y = 0; y < window_height; y++) {
-			data_y = (size_t) (zoom_y + y / zoom);
+			data_y = (ssize_t) (zoom_y) + (y / zoom);
 			if (data_y < 0 || data_y >= data_height)
 				continue;
 
 			for (x = 0; x < window_width; x++) {
-				data_x = (size_t) (zoom_x + x / zoom);
+				data_x = (ssize_t) (zoom_x) + (x / zoom);
 				if (data_x < 0 || data_x >= data_width)
 					continue;
 
@@ -290,8 +308,8 @@ vis(void)
 		DrawTexture(tex, 0, 0, WHITE);
 
 		if (show_pos) {
-			data_x = zoom_x + mouse_x / zoom;
-			data_y = zoom_y + mouse_y / zoom;
+			data_x = (ssize_t) zoom_x + (mouse_x / zoom);
+			data_y = (ssize_t) zoom_y + (mouse_y / zoom);
 			if (data_x >= 0 && data_x < data_width
 					&& data_y >= 0 && data_y < data_height) {
 				pos = data_y * data_width + data_x;
@@ -342,7 +360,7 @@ main(int argc, const char **argv)
 	if (!strcmp(file_path, "-"))
 		file_path = "/dev/stdin";
 
-	file_data = readfile(file_path, &data_len);
+	file_data = read_file(file_path, &data_len);
 
 	value_colors = malloc(sizeof(Color) * data_len);
 	if (!value_colors) err(1, "malloc");