Disable certain OpenGL functions on Apple platforms. (#644)

Apple platforms only support up to OpenGL 4.1.

libs/sdl/gl.c

@@ -327,11 +327,15 @@ HL_PRIM void HL_NAME(gl_tex_image3d)( int target, int level, int internalFormat,
 }
 
 HL_PRIM void HL_NAME(gl_tex_storage2d)( int target, int levels, int internalFormat, int width, int height) {
+#ifndef __APPLE__
 	glTexStorage2D(target, levels, internalFormat, width, height);
+#endif
 }
 
 HL_PRIM void HL_NAME(gl_tex_storage3d)( int target, int levels, int internalFormat, int width, int height, int depth) {
+#ifndef __APPLE__
 	glTexStorage3D(target, levels, internalFormat, width, height, depth);
+#endif
 }
 
 HL_PRIM void HL_NAME(gl_tex_image2d_multisample)( int target, int samples, int internalFormat, int width, int height, bool fixedsamplelocations) {
@@ -655,12 +659,18 @@ HL_PRIM void HL_NAME(gl_uniform_block_binding)( vdynamic *p, int index, int bind
 // SSBOs
 
 HL_PRIM int HL_NAME(gl_get_program_resource_index)( vdynamic *p, int type, vstring *name ) {
+#ifndef __APPLE__
 	char *cname = hl_to_utf8(name->bytes);
 	return (int)glGetProgramResourceIndex(p->v.i, type, cname);
+#else
+	return 0;
+#endif
 }
 
 HL_PRIM void HL_NAME(gl_shader_storage_block_binding)( vdynamic *p, int index, int binding ) {
+#ifndef __APPLE__
 	glShaderStorageBlockBinding(p->v.i, index, binding);
+#endif
 }
 
 DEFINE_PRIM(_BOOL,gl_init,_NO_ARG);

libs/sdl/sdl/GL.hx

@@ -256,10 +256,12 @@ class GL {
 	public static function compressedTexSubImage3D( target : Int, level : Int, xoffset : Int, yoffset : Int, zoffset : Int, width : Int, height : Int, depth : Int, format : Int, type : Int, image : hl.Bytes ) {
 	}
 
+	/** Requires OpenGL 4.2+, therefore not supported on Apple platforms **/
 	@:hlNative("?sdl","gl_tex_storage2d")
 	public static function texStorage2D( target : Int, levels : Int, internalFormat : Int, width : Int, height : Int ) {
 	}
 
+	/** Requires OpenGL 4.2+, therefore not supported on Apple platforms **/
 	@:hlNative("?sdl","gl_tex_storage3d")
 	public static function texStorage3D( target : Int, levels : Int, internalFormat : Int, width : Int, height : Int, depth : Int ) {
 	}
@@ -448,11 +450,13 @@ class GL {
 
 	// ssbos
 
+	/** Requires OpenGL 4.3+, therefore not supported on Apple platforms **/
 	@:hlNative("?sdl","gl_get_program_resource_index")
 	public static function getProgramResourceIndex( p : Program, type : Int, name : String ) : Int {
 		return 0;
 	}
 
+	/** Requires OpenGL 4.3+, therefore not supported on Apple platforms **/
 	@:hlNative("?sdl","gl_shader_storage_block_binding")
 	public static function shaderStorageBlockBinding( p : Program, blockIndex : Int, blockBinding : Int ) : Void {
 	}