Remove functions not used when STBI_NO_PNG and STBI_NO_HDR are defined

src/video/stb_image.h

@@ -505,6 +505,7 @@ STBIDEF int      stbi_is_16_bit_from_file(FILE *f);
 
 
 
+#ifndef STBI_NO_PNG
 // for image formats that explicitly notate that they have premultiplied alpha,
 // we just return the colors as stored in the file. set this flag to force
 // unpremultiplication. results are undefined if the unpremultiply overflow.
@@ -523,16 +524,19 @@ STBIDEF void stbi_set_flip_vertically_on_load(int flag_true_if_should_flip);
 STBIDEF void stbi_set_unpremultiply_on_load_thread(int flag_true_if_should_unpremultiply);
 STBIDEF void stbi_convert_iphone_png_to_rgb_thread(int flag_true_if_should_convert);
 STBIDEF void stbi_set_flip_vertically_on_load_thread(int flag_true_if_should_flip);
+#endif
 
 // ZLIB client - used by PNG, available for other purposes
 
+#ifndef STBI_NO_ZLIB
 STBIDEF char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen);
 STBIDEF char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, int len, int initial_size, int *outlen, int parse_header);
 STBIDEF char *stbi_zlib_decode_malloc(const char *buffer, int len, int *outlen);
 STBIDEF int   stbi_zlib_decode_buffer(char *obuffer, int olen, const char *ibuffer, int ilen);
 
 STBIDEF char *stbi_zlib_decode_noheader_malloc(const char *buffer, int len, int *outlen);
 STBIDEF int   stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen);
+#endif
 
 
 #ifdef __cplusplus
@@ -1576,10 +1580,12 @@ STBIDEF void   stbi_ldr_to_hdr_gamma(float gamma) { stbi__l2h_gamma = gamma; }
 STBIDEF void   stbi_ldr_to_hdr_scale(float scale) { stbi__l2h_scale = scale; }
 #endif
 
+#ifndef STBI_NO_HDR
 static float stbi__h2l_gamma_i=1.0f/2.2f, stbi__h2l_scale_i=1.0f;
 
 STBIDEF void   stbi_hdr_to_ldr_gamma(float gamma) { stbi__h2l_gamma_i = 1/gamma; }
 STBIDEF void   stbi_hdr_to_ldr_scale(float scale) { stbi__h2l_scale_i = 1/scale; }
+#endif
 
 
 //////////////////////////////////////////////////////////////////////////////