stbi: disable unused img decoders

saves a little space

- STBI_REALLOC_SIZED actually unneeded by remaining code
- fix unused warnings in stb_image.h when features disabled

Author: MartinPulec

src/utils/image_delegate.c

@@ -54,12 +54,17 @@
 
 static void
 gpujpeg_cuda_free_host(void* ptr);
-static void*
-gpujpeg_cuda_realloc_sized_host(void* ptr, int oldsz, int newsz);
+#define STBI_NO_JPEG
+#define STBI_NO_PNG
+#define STBI_NO_PSD
+#define STBI_NO_GIF
+#define STBI_NO_HDR
+#define STBI_NO_PIC
+#define STBI_NO_PNM
 // we want use custom allocator but only way to do this in stbi is to define the below
 #define STBI_MALLOC gpujpeg_cuda_malloc_host
 #define STBI_FREE gpujpeg_cuda_free_host
-#define STBI_REALLOC_SIZED gpujpeg_cuda_realloc_sized_host
+#define STBI_REALLOC_SIZED unneeded_so_undefined
 #define STB_IMAGE_IMPLEMENTATION
 #include "stb_image.h"
 
@@ -74,6 +79,7 @@ gpujpeg_cuda_free_host(void* ptr)
     GPUJPEG_CHECK_EX(cudaFreeHost(ptr), "Could not free host pointer", );
 }
 
+#if 0
 static void*
 gpujpeg_cuda_realloc_sized_host(void* ptr, int oldsz, int newsz)
 {
@@ -85,6 +91,7 @@ gpujpeg_cuda_realloc_sized_host(void* ptr, int oldsz, int newsz)
     gpujpeg_cuda_free_host(ptr);
     return nptr;
 }
+#endif
 
 static int
 stbi_load_delegate(const char* filename, size_t* image_size, void** image_data, allocator_t alloc)

src/utils/stb_image.h

@@ -1066,6 +1066,7 @@ static void *stbi__malloc_mad4(int a, int b, int c, int d, int add)
 }
 #endif
 
+#ifndef STBI_NO_JPEG
 // returns 1 if the sum of two signed ints is valid (between -2^31 and 2^31-1 inclusive), 0 on overflow.
 static int stbi__addints_valid(int a, int b)
 {
@@ -1082,6 +1083,7 @@ static int stbi__mul2shorts_valid(int a, int b)
    if (b < 0) return a <= SHRT_MIN / b; // same as a * b >= SHRT_MIN
    return a >= SHRT_MIN / b;
 }
+#endif
 
 // stbi__err - error
 // stbi__errpf - error returning pointer to float
@@ -7673,6 +7675,7 @@ static int stbi__info_main(stbi__context *s, int *x, int *y, int *comp)
 
 static int stbi__is_16_main(stbi__context *s)
 {
+   (void) s;
    #ifndef STBI_NO_PNG
    if (stbi__png_is16(s))  return 1;
    #endif