From a6eedf71b5d37cb5d9baa25f75df9e315760cf8b Mon Sep 17 00:00:00 2001
From: Ivan Mahonin <bh@icystar.com>
Date: May 02 2022 07:54:36 +0000
Subject: fix endianess


---

diff --git a/img.ldr.tga.inc.c b/img.ldr.tga.inc.c
index 0cd26b4..cab8a00 100644
--- a/img.ldr.tga.inc.c
+++ b/img.ldr.tga.inc.c
@@ -5,54 +5,60 @@ typedef struct {
   unsigned char  idLength;
   unsigned char  colormapType;
   unsigned char  imageType;
-  unsigned short colormapIndex;
-  unsigned short colormapLength;
+  unsigned char  colormapIndex[2];
+  unsigned char  colormapLength[2];
   unsigned char  colormapSize;
-  unsigned short xOrigin;
-  unsigned short yOrigin;
-  unsigned short width;
-  unsigned short height;
+  unsigned char  xOrigin[2];
+  unsigned char  yOrigin[2];
+  unsigned char  width[2];
+  unsigned char  height[2];
   unsigned char  pixelSize;
   unsigned char  attributes;
 } TgaHeader;
 #pragma pack(pop)
 
 
+unsigned short getLEU16(unsigned char *c)
+    { return c[0] | ((unsigned short)c[1] << 8); }
+void setLEU16(unsigned char *c, unsigned short i)
+    { c[0] = i; c[1] = i >> 8; }
+
+
 int imageLoadTga(const char *path, int *outWidth, int *outHeight, unsigned char **pixels) {
   *outWidth = *outHeight = 0; *pixels = NULL;
 
-	FILE *f = fopen(path, "rb");
-	if (!f) {
+  FILE *f = fopen(path, "rb");
+    if (!f) {
     fprintf(stderr, "Cannot open for read: %s\n", path);
     fflush(stderr);
     return FALSE;
   }
 
-	TgaHeader header = {};
-	fread(&header, sizeof(header), 1, f); // todo: endianess
+  TgaHeader header = {};
+  fread(&header, sizeof(header), 1, f); // todo: endianess
 
-	//printf("%d %d %d %d %d\n", header.imageType, header.width, header.height, header.colormapType, header.pixelSize);
+  //printf("%d %d %d %d %d\n", header.imageType, header.width, header.height, header.colormapType, header.pixelSize);
 
-	if ( header.imageType != 2
-	  || !header.width
-	  || !header.height
-	  || header.colormapType
-	  || (header.pixelSize != 24 && header.pixelSize != 32)
+  if ( header.imageType != 2
+    || !header.width
+    || !header.height
+    || header.colormapType
+    || (header.pixelSize != 24 && header.pixelSize != 32)
   ) {
     fprintf(stderr, "Unsupported format. Only uncompressed 24 or 32 bits TGA are supported: %s\n", path);
     fflush(stderr);
     return FALSE;
-	}
+  }
 
   fseek(f, header.idLength, SEEK_CUR);
 
-  *outWidth = header.width;
-  *outHeight = header.height;
-  int rowSize = *outWidth*4;
-  int size = *outHeight*rowSize;
+  int w = *outWidth = getLEU16(header.width);
+  int h = *outHeight = getLEU16(header.height);
+  int rowSize = w*4;
+  int size = h*rowSize;
   *pixels = (unsigned char*)calloc(1, size);
   unsigned char *row = *pixels + size;
-  for(unsigned short r = header.height; r; --r, row -= rowSize) {
+  for(unsigned short r = h; r; --r, row -= rowSize) {
     for(unsigned char *c = row - rowSize; c < row; c += 4) {
       c[2] = fgetc(f);
       c[1] = fgetc(f);
@@ -60,33 +66,33 @@ int imageLoadTga(const char *path, int *outWidth, int *outHeight, unsigned char 
       c[3] = header.pixelSize == 32 ? fgetc(f) : 255;
     }
   }
-	fclose(f);
+  fclose(f);
 
-	return TRUE;
+  return TRUE;
 }
 
 
 int imageSaveTga(const char *path, int width, int height, const unsigned char *pixels) {
-  if (width <= 0 || height <= 0 || !pixels) return FALSE;
+  if (width <= 0 || height <= 0 || width > 0xffff || height > 0xffff || !pixels) return FALSE;
 
-	FILE *f = fopen(path, "wb");
-	if (!f) {
+  FILE *f = fopen(path, "wb");
+  if (!f) {
     fprintf(stderr, "Cannot open file for write: %s\n", path);
     fflush(stderr);
     return FALSE;
   }
 
-	TgaHeader header = {};
-	header.imageType = 2;
-	header.width = width;
-	header.height = height;
-	header.pixelSize = 32;
-	fwrite(&header, sizeof(header), 1, f); // todo: endianess
+  TgaHeader header = {};
+  header.imageType = 2;
+  setLEU16(header.width, width);
+  setLEU16(header.height, height);
+  header.pixelSize = 32;
+  fwrite(&header, sizeof(header), 1, f); // todo: endianess
 
   int rowSize = width*4;
   int size = height*rowSize;
   const unsigned char *row = pixels + size;
-  for(unsigned short r = header.height; r; --r, row -= rowSize) {
+  for(unsigned short r = height; r; --r, row -= rowSize) {
     for(const unsigned char *c = row - rowSize; c < row; c += 4) {
       fputc(c[2], f);
       fputc(c[1], f);
@@ -94,8 +100,8 @@ int imageSaveTga(const char *path, int width, int height, const unsigned char *p
       fputc(c[3], f);
     }
   }
-	fclose(f);
+  fclose(f);
 
-	return TRUE;
+  return TRUE;
 }