From 21e7d15a1b6fae60747b42165e67fcfb9e74cd25 Mon Sep 17 00:00:00 2001
From: Joseph Ferano <joseph@ferano.io>
Date: Fri, 6 Oct 2023 10:40:44 +0700
Subject: [PATCH] texturepacker: Check if files provided can be loaded as
 images

---
 .gitignore                 |   1 +
 game/Makefile              |   4 ++
 game/tools/texturepacker.c | 101 ++++++++++++++++++++++++++++++++++++-
 3 files changed, 105 insertions(+), 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index 23bbbb8..3ccef61 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 /libs/glad/glad.o
 /opengl
 /game/main
+/game/texturepacker
diff --git a/game/Makefile b/game/Makefile
index 84dd10d..7ea0542 100644
--- a/game/Makefile
+++ b/game/Makefile
@@ -10,6 +10,10 @@ RM=rm -vf
 build: clean
 	$(CC) $(CFLAGS) $(LDLIBS) $(INCLUDES) $(OBJECTS) $(P).c -o $(P)
 
+.PHONY: texturepacker
+texturepacker:
+	$(CC) $(CFLAGS) $(LDLIBS) $(INCLUDES) $(OBJECTS) tools/texturepacker.c -o texturepacker
+
 .PHONY: run
 run: build
 	./$(P)
diff --git a/game/tools/texturepacker.c b/game/tools/texturepacker.c
index da03a5e..9750cfe 100644
--- a/game/tools/texturepacker.c
+++ b/game/tools/texturepacker.c
@@ -1,13 +1,112 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <stdbool.h>
 
 #define STB_IMAGE_IMPLEMENTATION
+#define STBI_FAILURE_USERMSG
 #include "stb_image.h"
 
-int main(void) {
+struct image {
+    char* filename;
+    unsigned char* image_data;
+    int width;
+    int height;
+    int channels;
+};
 
+int main(int argc, char* argv[]) {
+    if (argc == 1) {
+        fprintf(stderr, "Must provide image files to pack");
+        exit(-1);
+    }
+    if (argc == 2) {
+        fprintf(stderr, "Please provide at least 2 images to pack");
+        exit(-1);
+    }
+    struct image* images = calloc(argc - 1, sizeof(struct image));
+    if (images == NULL) {
+        fprintf(stderr, "Failed to alloc image data array");
+        exit(-1);
+    }
+    //-------------------------------------
+    // First get the image info, make sure the file is an image and it exists
+    //-------------------------------------
+    int image_count = argc - 1;
+    for (int i = 0; i < argc - 1; i++) {
+        struct image* img = &images[i];
+        img->filename = argv[i+1];
 
+        int result = stbi_info(img->filename, &img->width, &img->height, &img->channels);
+        if (result != 1) {
+            char *errorMsg = "Cannot load image '%s': %s\n";
+            fprintf(stderr, errorMsg, img->filename, stbi_failure_reason());
+            exit(-1);
+        }
+    }
+    //-------------------------------------
+    // Now run the packing algorithm
+    // Note: How to get the minimum power of 2 texture size. Note that this is still
+    // very inefficient because we're just naively putting them all at 0
+    // x = log2(max(width, height)) 
+    // width or height = 2 ** (x + 1)
+    // This is super inefficient texture packing but I just want to get it working first
+    //-------------------------------------
 
+    int totalh = 0, maxw = 0;
+    for (int i = 0; i < image_count; i++) {
+        totalh += images[i].height;
+        if (images[i].width > maxw) {
+            maxw = images[i].width;
+        }
+    }
+    int max = totalh > maxw ? totalh : maxw;
+    int exp = (int)log2(max) + 1;
+    int size = (int)pow(2, exp);
+    unsigned char* buf = calloc(size*size, sizeof(char));
+    (void)buf;
+
+    //-------------------------------------
+    // Now load each texture one by one, write to the new image buffer, and free, before
+    // loading the next one
+    //-------------------------------------
+    for (int i = 0; i < argc - 1; i++) {
+        images[i].filename = argv[i+1];
+
+        // int width, height, channels;
+        // images[i].image_data = (unsigned char*)stbi_load(images[i].filename,
+        //                               &width,
+        //                               &height,
+        //                               &channels,
+        //                               4);
+
+        // images[i].width = (short)width;
+        // images[i].height = (short)height;
+        // images[i].channels = (char)channels;
+        images[i].image_data = (unsigned char*)stbi_load(images[i].filename,
+                                      &images[i].width,
+                                      &images[i].height,
+                                      &images[i].channels,
+                                      4);
+        if (images[i].image_data == NULL) {
+            char *errorMsg = "Could not load data for image '%s': %s";
+            fprintf(stderr, errorMsg, images[i].filename, stbi_failure_reason());
+            // QUESTION: Should we clean up here?
+            exit(-1);
+        }
+    }
+    // unsigned char* image_bytes = images[0].image_data;
+    // int b = 0;
+    // while (image_bytes) {
+    //     if (image_bytes[b]) {
+    //         printf("R:%u G:%u B:%u A:%u\n", image_bytes[b], image_bytes[b+1], image_bytes[b+2], image_bytes[b+3]);
+    //     }
+    //     b += 4;
+    //     image_bytes += 4;
+    // }
+    for (int i = 0; i < image_count; i++) {
+        stbi_image_free(images[i].image_data);
+    }
+    // for (int i = )
     return 0;
 }