/*

 Copyright (C) 2015 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 Functions for loading source files for shaders.

 */

#include "sourceUtil.h"

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

demoSource* srcLoadSource(const char* filepathname)

{

    demoSource* source = (demoSource*) calloc(sizeof(demoSource), 1);

    // Check the file name suffix to determine what type of shader this is

    const char* suffixBegin = filepathname + strlen(filepathname) - 4;

    if(0 == strncmp(suffixBegin, ".fsh", 4))

    {

        source->shaderType = GL_FRAGMENT_SHADER;

    }

    else if(0 == strncmp(suffixBegin, ".vsh", 4))

    {

        source->shaderType = GL_VERTEX_SHADER;

    }

    else

    {

        // Unknown suffix

        source->shaderType = 0;

    }

    FILE* curFile = fopen(filepathname, "r");

    // Get the size of the source

    fseek(curFile, 0, SEEK_END);

    long fileSize = ftell (curFile);

    // Add 1 to the file size to include the null terminator for the string

    source->byteSize =  (GLsizei)fileSize + 1;

    // Alloc memory for the string

    source->string = malloc(source->byteSize);

    // Read entire file into the string from beginning of the file

    fseek(curFile, 0, SEEK_SET);

    fread(source->string, 1, fileSize, curFile);

    fclose(curFile);

    // Insert null terminator

    source->string[fileSize] = 0;

    return source;

}

void srcDestroySource(demoSource* source)

{

    free(source->string);

    free(source);

}