From 933ee23bd3f97b9fc45a36ad8e3f75fea45d6202 Mon Sep 17 00:00:00 2001
From: KikooDX <kikoodx@paranoici.org>
Date: Thu, 18 Mar 2021 18:30:36 +0100
Subject: [PATCH] Level read and write.

---
 .gitignore      |  3 ++
 CMakeLists.txt  |  2 +-
 include/level.h |  4 +++
 src/level.c     | 90 ++++++++++++++++++++++++++++++++++++++++++-------
 src/main.c      |  5 +--
 5 files changed, 89 insertions(+), 15 deletions(-)

diff --git a/.gitignore b/.gitignore
index 567609b..3f0c725 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,4 @@
 build/
+
+# KBLE (Zig) files
+backup_*.kble
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 08e4796..2c3ff4a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,4 +14,4 @@ target_compile_options(${PROJECT_NAME} PRIVATE
 	-Wunreachable-code -Wstrict-prototypes -Wmissing-prototypes
 	-Wold-style-definition -Werror-implicit-function-declaration
 	-ansi -pedantic-errors -g -Os)
-target_link_libraries(${PROJECT_NAME} raylib)
+#target_link_libraries(${PROJECT_NAME} raylib)
diff --git a/include/level.h b/include/level.h
index 997da33..835cf16 100644
--- a/include/level.h
+++ b/include/level.h
@@ -1,3 +1,6 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* Copyright (C) 2021 KikooDX */
+
 #pragma once
 
 struct Level {
@@ -8,3 +11,4 @@ struct Level {
 
 void level_read(struct Level*, char *path);
 void level_free(struct Level*);
+void level_write(struct Level level, char *path);
diff --git a/src/level.c b/src/level.c
index 188d6e1..19668ae 100644
--- a/src/level.c
+++ b/src/level.c
@@ -10,13 +10,13 @@
 static const int kble_fmt_version = 0;
 
 static int read_byte(FILE *file);
-static int read_byte_group(FILE *file, int number);
+static int read_byte_group(FILE *file, int size);
+static void write_byte(FILE *file, unsigned char byte);
+static void write_byte_group(FILE *file, int value, int size);
 
 void level_read(struct Level *level, char *path) {
 	FILE *file = NULL;
 	int byte = 0;
-	int width = 0;
-	int height = 0;
 	int tile_size = 0;
 	int level_size = 0;
 	int tile = 0;
@@ -25,7 +25,7 @@ void level_read(struct Level *level, char *path) {
 	/* open file in read mode */
 	file = fopen(path, "rb");
 	if (file == NULL) {
-		fprintf(stderr, "ERROR: Cannot open input file %s\n", path);
+		fprintf(stderr, "ERROR: cannot open input file %s\n", path);
 		exit(EXIT_FAILURE);
 	}
 
@@ -40,12 +40,12 @@ void level_read(struct Level *level, char *path) {
 	/* get tile size (in bytes) */
 	tile_size = read_byte(file);
 	/* get width */
-	width = read_byte_group(file, 2);
+	level->width = read_byte_group(file, 2);
 	/* get height */
-	height = read_byte_group(file, 2);
+	level->height = read_byte_group(file, 2);
 
 	/* allocate memory for data */
-	level_size = width * height;
+	level_size = level->width * level->height;
 	if (level->data == NULL) {
 		level->data = malloc(level_size * sizeof(int));
 	} else {
@@ -71,9 +71,52 @@ void level_free(struct Level *level) {
 	free(level->data);
 }
 
-/* Read a single byte safely (handles EOF). */
+void level_write(struct Level level, char *path) {
+	FILE *file = NULL;
+	int tile = 0;
+	int tile_size = 0;
+	int max_tile_size = 1;
+	int i = 0;
+	const int level_size = level.width * level.height;
+
+	/* open file in write mode */
+	file = fopen(path, "wb");
+	if (file == NULL) {
+		fprintf(stderr, "ERROR: cannot open output file %s\n", path);
+		exit(EXIT_FAILURE);
+	}
+
+	/* find longest value in data (in bytes) */
+	for (i = 0; i < level_size; i += 1) {
+		tile = level.data[i];
+		tile_size = 1;
+		while (tile >>= 8)
+			tile_size += 1;
+		if (tile_size > max_tile_size)
+			max_tile_size = tile_size;
+	}
+
+	/* write KBLE format version */
+	write_byte(file, kble_fmt_version);
+	/* write tile size (in bytes) */
+	write_byte(file, max_tile_size);
+	/* write width */
+	write_byte_group(file, level.width, 2);
+	/* write height */
+	write_byte_group(file, level.height, 2);
+
+	/* write level content */
+	for (i = 0; i < level_size; i += 1) {
+		write_byte_group(file, level.data[i], max_tile_size);
+	}
+
+	/* close file */
+	fclose(file);
+}
+
+/* Read a single byte safely (handle EOF). */
 static int read_byte(FILE *file) {
-	const int byte = getc(file);
+	const int byte = fgetc(file);
 	if (byte == EOF) {
 		fprintf(stderr, "ERROR: unexpected EOF\n");
 		exit(EXIT_FAILURE);
@@ -82,15 +125,38 @@ static int read_byte(FILE *file) {
 }
 
 /* Read multiple bytes and "merge" them into one integer. */
-static int read_byte_group(FILE *file, int number) {
+static int read_byte_group(FILE *file, int size) {
 	int byte = 0;
 	int merged = 0;
 	int i = 0;
-	int shift = number * 8;
-	for (i = 0; i < number; i += 1) {
+	int shift = size * 8;
+	for (i = 0; i < size; i += 1) {
 		shift -= 8;
 		byte = read_byte(file);
 		merged |= byte << shift;
 	}
 	return merged;
 }
+
+/* Write a single byte safely (handle EOF). */
+static void write_byte(FILE *file, unsigned char byte) {
+	const int result = fputc(byte, file);
+	if (result == EOF) {
+		fprintf(stderr, "ERROR: file write error\n");
+		exit(EXIT_FAILURE);
+	}
+}
+
+/* Write an integer as multiple bytes. */
+static void write_byte_group(FILE *file, int value, int size) {
+	int byte = 0;
+	int shift = size * 8;
+	int i = 0;
+	const int mask = (1 << 8) - 1;
+	for (i = 0; i < size; i += 1) {
+		shift -= 8;
+		byte = value >> shift;
+		byte &= mask;
+		write_byte(file, byte);
+	}
+}
diff --git a/src/main.c b/src/main.c
index 7da20ee..79e4c38 100644
--- a/src/main.c
+++ b/src/main.c
@@ -10,12 +10,13 @@ int main(int argc, char **argv) {
 	struct Level level;
 	level.data = NULL;
 
-	if (argc != 2) {
-		fprintf(stderr, "ERROR: expected 1 argument, got %d\n", argc-1);
+	if (argc != 3) {
+		fprintf(stderr, "ERROR: expected 2 argument, got %d\n", argc-1);
 		return EXIT_FAILURE;
 	}
 
 	level_read(&level, argv[1]);
+	level_write(level, argv[2]);
 	level_free(&level);
 
 	return EXIT_SUCCESS;