Merge in featured-list-creator into utils/

Originally a C program (previously Python script) at https://github.com/principia-game/featured-list-creator for creating fl.cache files for the community site, merge into the main repository so it is with all the other util programs.

.github/workflows/build_utils.yml

@@ -16,6 +16,11 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
+      - name: Install deps
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libjansson-dev
+
       - name: Build
         run: |
           cd utils

utils/Makefile

@@ -1,4 +1,4 @@
-SUBDIRS := lvl-icon-extractor lvlbuf-decompressor lvledit progress-get
+SUBDIRS := featured-list-creator lvl-icon-extractor lvlbuf-decompressor lvledit progress-get
 
 .PHONY: all clean $(SUBDIRS)
 

utils/README.md

@@ -9,6 +9,7 @@ This directory contains utility scripts and programs used for Principia developm
 ## Programs
 Most of these programs rely on source files from the main Principia codebase and need to be compiled to run. Likely only works on Linux. You can use the `Makefile` in each directory or run `make` in the `utils` directory to build all of them.
 
+- `featured-list-creator`: Generate a `fl.cache` file for use on the Principia community site
 - `lvl-icon-extractor`: Extract the embedded level icon in a Principia level file
 - `lvlbuf-decompressor`: Decompress the level buffer of a Principia level file
 - `lvledit`: Edit metadata of Principia level files

utils/featured-list-creator/Makefile

@@ -0,0 +1,27 @@
+BIN = ../bin
+PRINCIPIA = ../..
+PROGRAM = featured-list-creator
+SRCS := main.c
+
+# always static unless you do STATIC=0
+STATIC ?= 1
+
+CC ?= gcc
+CFLAGS ?= -O2 -ffunction-sections -fdata-sections
+LDFLAGS ?= -Wl,--gc-sections
+ifeq ($(STATIC),1)
+	LDFLAGS += -l:libjansson.a
+else
+	LDFLAGS += -ljansson
+endif
+
+all: $(BIN)/$(PROGRAM)
+
+$(BIN)/$(PROGRAM): $(SRCS)
+	@mkdir -p $(BIN)
+	$(CC) $(CFLAGS) $(INCLUDES) -o $@ $^ $(LDFLAGS)
+
+clean:
+	rm $(BIN)/$(PROGRAM)
+
+.PHONY: all clean

utils/featured-list-creator/README.md

@@ -0,0 +1,38 @@
+# Featured List Creator
+This is a C program that generates a featured list file (`fl.cache`) from JSON data and images, which is served by the Principia community site to display featured levels and getting started links in the main menu.
+
+The program requires the jansson library for JSON parsing, and will attempt to statically link against it by default. You can do `make STATIC=0` to link dynamically instead.
+
+## Usage
+There are two optional arguments for specifying the input JSON file and output `fl.cache` file. The default values are below:
+
+```bash
+./featured-list-creator data/data.json fl.cache
+```
+
+## Format
+The format of the input JSON file is as follows:
+
+```json
+{
+	"featured_levels": [
+		{
+			"id": 1,
+			"name": "Name",
+			"author": "Author",
+			"jpeg_image": "level_thumbnail.jpg"
+		}
+		[...]
+	],
+
+	"gettingstarted_list": [
+		{
+			"name": "Link 1",
+			"link": "https://example.org"
+		}
+		[...]
+	]
+}
+```
+
+The paths to the JPEG images are relative to the current working directory when running the program.

utils/featured-list-creator/main.c

@@ -0,0 +1,98 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <jansson.h>
+
+void write_u32(FILE *f, uint32_t value) {
+    fwrite(&value, sizeof(uint32_t), 1, f);
+}
+
+void write(FILE *f, const char* value) {
+    fwrite(value, 1, strlen(value), f);
+}
+
+#define GET_JSON_INTEGER(obj, key) json_integer_value(json_object_get((obj), (key)))
+#define GET_JSON_STRING(obj, key) json_string_value(json_object_get((obj), (key)))
+
+int main(int argc, char *argv[]) {
+    if (argc < 3) {
+        printf("Usage: %s [data.json] [fl.cache]\n", argv[0]);
+        return 1;
+    }
+
+    const char *input_filename = argv[1];
+    const char *output_filename = argv[2];
+
+    json_t *root; json_error_t error;
+    root = json_load_file(input_filename, 0, &error);
+    if (!root) {
+        printf("Error loading JSON file: %s\n", error.text);
+        return 1;
+    }
+
+    json_t *featured_levels = json_object_get(root, "featured_levels");
+    json_t *gettingstarted_list = json_object_get(root, "gettingstarted_list");
+
+    if (json_array_size(featured_levels) > 4 || json_array_size(gettingstarted_list) > 12)
+        printf("Array lengths are likely too large for Principia, but carry on.\n");
+
+    FILE *f = fopen(output_filename, "wb+");
+    if (!f) {
+        printf("Error opening output file\n");
+        return 1;
+    }
+
+    size_t index;
+    json_t *feat_level, *gettingstarted;
+
+    write_u32(f, json_array_size(featured_levels)); // featured_level_count
+    json_array_foreach(featured_levels, index, feat_level) {
+        uint32_t id = GET_JSON_INTEGER(feat_level, "id");
+        const char *name = GET_JSON_STRING(feat_level, "name");
+        const char *author = GET_JSON_STRING(feat_level, "author");
+        const char *jpeg_image_path = GET_JSON_STRING(feat_level, "jpeg_image");
+
+        FILE *jpeg_file = fopen(jpeg_image_path, "rb");
+        if (!jpeg_file) {
+            printf("Error opening JPEG image file %s\n", jpeg_image_path);
+            fclose(f);
+            return 1;
+        }
+
+        fseek(jpeg_file, 0, SEEK_END);
+        long jpeg_size = ftell(jpeg_file);
+        fseek(jpeg_file, 0, SEEK_SET);
+
+        unsigned char *jpeg_stream = malloc(jpeg_size);
+        fread(jpeg_stream, 1, jpeg_size, jpeg_file);
+        fclose(jpeg_file);
+
+        write_u32(f, id);             // fl_id
+        write_u32(f, strlen(name));   // fl_name_size
+        write(f, name);               // fl_name
+        write_u32(f, strlen(author)); // fl_author_size
+        write(f, author);             // fl_author
+        write_u32(f, jpeg_size);      // fl_jpegstream_size
+        fwrite(jpeg_stream, 1, jpeg_size, f); // fl_jpegstream
+
+        free(jpeg_stream);
+    }
+
+    write_u32(f, 0); // Number of contests (unused and slightly broken)
+
+    write_u32(f, json_array_size(gettingstarted_list)); // gettingstarted_list_count
+    json_array_foreach(gettingstarted_list, index, gettingstarted) {
+        const char *name = GET_JSON_STRING(gettingstarted, "name");
+        const char *link = GET_JSON_STRING(gettingstarted, "link");
+
+        write_u32(f, strlen(name)); // gs_name_size
+        write(f, name);             // gs_name
+        write_u32(f, strlen(link)); // gs_link_size
+        write(f, link);             // gs_link
+    }
+
+    fclose(f);
+
+    return 0;
+}