Optionally emit an embeddable C-header for converted 4bpps

gfx.c

@@ -1,5 +1,6 @@
 // Copyright (c) 2015 YamaArashi, 2021-2025 red031000
 
+#include <stddef.h>
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -1015,7 +1016,36 @@ void ApplyCellsToImage(char *cellFilePath, struct Image *image, bool toPNG, bool
     FreeNCERCell(options);
 }
 
-void WriteImage(char *path, int numTiles, int bitDepth, int colsPerChunk, int rowsPerChunk, struct Image *image, bool invertColors)
+void WriteEmbeddableHeader(char *path, void *buffer, int bufferSize, const char *embedName)
+{
+    unsigned char *buf = buffer;
+
+    char *headerPath;
+    asprintf(&headerPath, "%s.h", path);
+    if (headerPath == NULL)
+        FATAL_ERROR("Failed to allocate embeddable header filepath.\n");
+
+    FILE *header = fopen(headerPath, "wb");
+    if (header == NULL)
+        FATAL_ERROR("Failed to open output file %s\n", headerPath);
+
+    fprintf(header, "#ifndef GUARD_EMBEDDABLE_%s_H\n", embedName);
+    fprintf(header, "#define GUARD_EMBEDDABLE_%s_H\n", embedName);
+    fprintf(header, "\n");
+    fprintf(header, "__attribute__((aligned(4))) const u8 %s[] = {\n", embedName);
+
+    for (int i = 0; i < bufferSize; i++)
+        fprintf(header, "    0x%02X,\n", buf[i]);
+
+    fprintf(header, "};\n");
+    fprintf(header, "\n");
+    fprintf(header, "#endif // GUARD_EMBEDDABLE_%s_H\n", embedName);
+
+    fclose(header);
+    free(headerPath);
+}
+
+void WriteImage(char *path, int numTiles, int bitDepth, int colsPerChunk, int rowsPerChunk, const char *embedName, struct Image *image, bool invertColors)
 {
     int tileSize = bitDepth * 8; // number of bytes per tile
 
@@ -1062,6 +1092,7 @@ void WriteImage(char *path, int numTiles, int bitDepth, int colsPerChunk, int ro
     }
 
     WriteWholeFile(path, buffer, bufferSize);
+    if (embedName != NULL) WriteEmbeddableHeader(path, buffer, bufferSize, embedName);
 
     free(buffer);
 }

gfx.h

@@ -53,7 +53,7 @@ struct Image {
 void ReadImage(char *path, int tilesWide, int bitDepth, int colsPerChunk, int rowsPerChunk, struct Image *image, bool invertColors);
 uint32_t ReadNtrImage(char *path, int tilesWide, int bitDepth, int colsPerChunk, int rowsPerChunk, struct Image *image, bool invertColors, uint32_t encodeMode, bool convertTo8Bpp, int palIndex, bool verbose);
 void ApplyCellsToImage(char *cellFilePath, struct Image *image, bool toPNG, bool snap, bool noSkip);
-void WriteImage(char *path, int numTiles, int bitDepth, int colsPerChunk, int rowsPerChunk, struct Image *image, bool invertColors);
+void WriteImage(char *path, int numTiles, int bitDepth, int colsPerChunk, int rowsPerChunk, const char *embedName, struct Image *image, bool invertColors);
 void WriteNtrImage(char *path, int numTiles, int bitDepth, int colsPerChunk, int rowsPerChunk, struct Image *image,
                    bool invertColors, bool clobberSize, bool byteOrder, bool version101, bool sopc, bool vram, bool scan,
                    uint32_t encodeMode, uint32_t mappingType, uint32_t key, bool wrongSize, bool convertTo4Bpp, int rotate);

main.c

@@ -2,6 +2,7 @@
 
 #include <ctype.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <stdbool.h>
 #include "global.h"
@@ -121,7 +122,7 @@ void ConvertPngToGba(char *inputPath, char *outputPath, struct PngToGbaOptions *
 
     ReadPng(inputPath, &image);
 
-    WriteImage(outputPath, options->numTiles, options->bitDepth, options->colsPerChunk, options->rowsPerChunk, &image, !image.hasPalette);
+    WriteImage(outputPath, options->numTiles, options->bitDepth, options->colsPerChunk, options->rowsPerChunk, options->embedName, &image, !image.hasPalette);
 
     FreeImage(&image);
 }
@@ -449,6 +450,7 @@ void HandlePngToGbaCommand(char *inputPath, char *outputPath, int argc, char **a
     options.bitDepth = bitDepth;
     options.colsPerChunk = 1;
     options.rowsPerChunk = 1;
+    options.embedName = NULL;
 
     for (int i = 3; i < argc; i++)
     {
@@ -493,6 +495,14 @@ void HandlePngToGbaCommand(char *inputPath, char *outputPath, int argc, char **a
             if (options.rowsPerChunk < 1)
                 FATAL_ERROR("rows per chunk must be positive.\n");
         }
+        else if (strcmp(option, "-embed") == 0)
+        {
+            if (i + 1 >= argc)
+                FATAL_ERROR("No symbol name after following \"%s\".\n", option);
+            i++;
+
+            options.embedName = argv[i];
+        }
         else
         {
             FATAL_ERROR("Unrecognized option \"%s\".\n", option);

options.h

@@ -21,6 +21,7 @@ struct PngToGbaOptions {
     int bitDepth;
     int colsPerChunk;
     int rowsPerChunk;
+    char *embedName;
 };
 
 struct PngToNtrOptions {