GLSL syntax problems: unexpected NEW_IDENTIFIER - c++

Question

I have just started to learn OpenGL, and am following this tutorial. I am having difficulty compiling the GLSL files that the tutorial uses.
Originally when I tried compiling them the compiler said that mesa did not support GLSL version 330 so I changed #version 330 core to #version 130. Now when I run it it gives me the following error:
3.0 Mesa 10.0.20Compiling shader : SimpleVertexShader.vertexshader
0:3(1): error: syntax error, unexpected NEW_IDENTIFIER
Compiling shader : SimpleFragmentShader.fragmentshader
Linking program
error: linking with uncompiled shader
I have searched on google and cannot find anyone with this problem. Anyway, here are all of the files in question:
SimpleVertexShader.vertexshader:
#version 130
layout(location = 0) in vec3 vertexPosition_modelspace;
void main(){
gl_Position.xyz = vertexPosition_modelspace;
gl_Position.w = 1.0;
}
SimpleFragmentShader.fragmentshader:
#version 130
out vec3 color;
void main() {
color = vec3(1,0,0);
}
loadShader.cpp:
#include <stdio.h>
#include <string>
#include <vector>
#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;
#include <stdlib.h>
#include <string.h>
#include <GL/glew.h>
GLuint LoadShaders(const char * vertex_file_path,const char * fragment_file_path){
// Create the shaders
GLuint VertexShaderID = glCreateShader(GL_VERTEX_SHADER);
GLuint FragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER);
// Read the Vertex Shader code from the file
std::string VertexShaderCode;
std::ifstream VertexShaderStream(vertex_file_path, std::ios::in);
if(VertexShaderStream.is_open())
{
std::string Line = "";
while(getline(VertexShaderStream, Line))
VertexShaderCode += "\n" + Line;
VertexShaderStream.close();
}
// Read the Fragment Shader code from the file
std::string FragmentShaderCode;
std::ifstream FragmentShaderStream(fragment_file_path, std::ios::in);
if(FragmentShaderStream.is_open()){
std::string Line = "";
while(getline(FragmentShaderStream, Line))
FragmentShaderCode += "\n" + Line;
FragmentShaderStream.close();
}
GLint Result = GL_FALSE;
int InfoLogLength;
// Compile Vertex Shader
printf("Compiling shader : %s\n", vertex_file_path);
char const * VertexSourcePointer = VertexShaderCode.c_str();
glShaderSource(VertexShaderID, 1, &VertexSourcePointer , NULL);
glCompileShader(VertexShaderID);
// Check Vertex Shader
glGetShaderiv(VertexShaderID, GL_COMPILE_STATUS, &Result);
glGetShaderiv(VertexShaderID, GL_INFO_LOG_LENGTH, &InfoLogLength);
std::vector<char> VertexShaderErrorMessage(InfoLogLength);
glGetShaderInfoLog(VertexShaderID, InfoLogLength, NULL, &VertexShaderErrorMessage[0]);
fprintf(stdout, "%s\n", &VertexShaderErrorMessage[0]);
// Compile Fragment Shader
printf("Compiling shader : %s\n", fragment_file_path);
char const * FragmentSourcePointer = FragmentShaderCode.c_str();
glShaderSource(FragmentShaderID, 1, &FragmentSourcePointer , NULL);
glCompileShader(FragmentShaderID);
// Check Fragment Shader
glGetShaderiv(FragmentShaderID, GL_COMPILE_STATUS, &Result);
glGetShaderiv(FragmentShaderID, GL_INFO_LOG_LENGTH, &InfoLogLength);
std::vector<char> FragmentShaderErrorMessage(InfoLogLength);
glGetShaderInfoLog(FragmentShaderID, InfoLogLength, NULL, &FragmentShaderErrorMessage[0]);
fprintf(stdout, "%s\n", &FragmentShaderErrorMessage[0]);
// Link the program
fprintf(stdout, "Linking program\n");
GLuint ProgramID = glCreateProgram();
glAttachShader(ProgramID, VertexShaderID);
glAttachShader(ProgramID, FragmentShaderID);
glLinkProgram(ProgramID);
// Check the program
glGetProgramiv(ProgramID, GL_LINK_STATUS, &Result);
glGetProgramiv(ProgramID, GL_INFO_LOG_LENGTH, &InfoLogLength);
std::vector<char> ProgramErrorMessage( max(InfoLogLength, int(1)) );
glGetProgramInfoLog(ProgramID, InfoLogLength, NULL, &ProgramErrorMessage[0]);
fprintf(stdout, "%s\n", &ProgramErrorMessage[0]);
glDeleteShader(VertexShaderID);
glDeleteShader(FragmentShaderID);
return ProgramID;
}
main.cpp:
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <GL/glew.h>
//#define GLFW_DLL // maybe some glu problems - look up
#include <GLFW/glfw3.h>
#include <glm/glm.hpp>
GLuint LoadShaders(const char * vertex_file_path,const char * fragment_file_path);
int main()
{
GLFWwindow * window;
if (!glfwInit()) {
std::cout << "Failed to initiate GLFW\n";
return -1;
}
glfwWindowHint(GLFW_SAMPLES, 4); //4x antialiasing
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); //version 3
//open a window and create context
window=glfwCreateWindow(1024,768,"Lerning", glfwGetPrimaryMonitor(), NULL);
if (!window) {
std::cout << "Failed to open window\n";
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
std::cout << glGetString(GL_VERSION);
// initialize GLEW
glewExperimental=GL_TRUE; //needed
GLenum err = glewInit();
std::cout << err;
if (err != GLEW_OK) {
std::cout << "Failed to initialize\n" << glewGetErrorString(err);
return -1;
}
GLuint VertexArrayID;
glGenVertexArrays(1, &VertexArrayID);
glBindVertexArray(VertexArrayID);
static const GLfloat g_vertex_buffer_data[] = {
-1.0f, -1.0f, 0.0f,
1.0f, 1.0f, 0.0f,
0.0f, 1.0f, 0.0f,
};
GLuint vertexbuffer;
glGenBuffers(1, &vertexbuffer);
glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data),
g_vertex_buffer_data, GL_STATIC_DRAW);
GLuint programID = LoadShaders("SimpleVertexShader.vertexshader",
"SimpleFragmentShader.fragmentshader");
while (!glfwWindowShouldClose(window)) {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glUseProgram(programID);
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
glVertexAttribPointer(
0,
3,
GL_FLOAT,
GL_FALSE,
0,
(void*)0
);
glDrawArrays(GL_TRIANGLES, 0, 3);
glDisableVertexAttribArray(0);
glfwSwapBuffers(window);
glfwPollEvents();
}
glfwTerminate();
return 0;
}

Answer 1

layout(location = 0) is not valid in GLSL 1.30. Layout qualifiers were introduced in GLSL 1.40. You will need to manually bind that vertex attribute location in your C++ code prior to linking your shaders.
// Check Fragment Shader
glGetShaderiv(FragmentShaderID, GL_COMPILE_STATUS, &Result);
glGetShaderiv(FragmentShaderID, GL_INFO_LOG_LENGTH, &InfoLogLength);
std::vector<char> FragmentShaderErrorMessage(InfoLogLength);
glGetShaderInfoLog(FragmentShaderID, InfoLogLength, NULL, &FragmentShaderErrorMessage[0]);
fprintf(stdout, "%s\n", &FragmentShaderErrorMessage[0]);
// Create the program
fprintf(stdout, "Linking program\n");
GLuint ProgramID = glCreateProgram();
glAttachShader(ProgramID, VertexShaderID);
glAttachShader(ProgramID, FragmentShaderID);
// Setup Vertex Attributes [NEW]
glBindAttribLocation (ProgramID, 0, "vertexPosition_modelspace");
// Link the program
glLinkProgram(ProgramID);
Chances are this attribute is going to be automatically assigned 0 by the GLSL implementation anyway once you remove the layout (location = 0), but you should go ahead and bind the location to do things the right way.