I’m trying use code in opengl 8th edition in triangles .cpp when compile code the windows opens and then i get this error
Shader compilation failed: error: 0:1: ‘’ : Incorrect GLSL version: 4
ERROR: 0:7: ‘fcolor’ : undeclared identifier
ERROR: 0:7: ‘assign’ : cannnot convert from ‘const 4-component vector of float’
to ‘float’
////////////////////////////////////////////////////////////
// //
// myTriangles2.cpp //
// //
////////////////////////////////////////////////////////////
#include <iostream>
using namespace std;
#include “vgl.h”
#include “LoadShaders.h”
enum VAO_IDs {Triangles, NumVAOs};
enum Buffer_IDs {ArrayBuffer, NumBuffers};
enum Attrib_IDs {vPosition = 0};
GLuint VAOs[NumVAOs];
GLuint Buffers[NumBuffers];
const GLuint NumVertices = 6;
void init(void)
{
glGenVertexArrays (NumVAOs, VAOs);
glBindVertexArray (VAOs[Triangles]);
GLfloat vertices [NumVertices][2] = {
{-0.90, -0.90}, //triangle 1
{ 0.85, 0.90},
{-0.90, 0.85},
{ 0.90, -0.85}, //triangle 2
{ 0.90, 0.90},
{-0.85, 0.90}
};
glGenBuffers(NumBuffers, Buffers);
glBindBuffer(GL_ARRAY_BUFFER, Buffers[ArrayBuffer]);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
ShaderInfo shaders[] = {
{GL_VERTEX_SHADER, "triangles.vert"},
{GL_FRAGMENT_SHADER, "triangles.frag"},
{GL_NONE, NULL}
};
GLuint program = LoadShaders(shaders);
glUseProgram(program);
glVertexAttribPointer(vPosition, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0) );
glEnableVertexAttribArray(vPosition);
}
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT);
glBindVertexArray(VAOs[Triangles]);
glDrawArrays(GL_TRIANGLES, 0, NumVertices);
glFlush();
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGBA);
glutInitWindowPosition(523, 512);
glutInitContextVersion(4,0);
glutInitContextProfile(GLUT_CORE_PROFILE);
glutCreateWindow(argv[0]);
glewExperimental = true;
if (glewInit())
{
cerr << "Unable to initialize glew.....exiting" << endl;
exit(EXIT_FAILURE);
}
init();
glutDisplayFunc(display);
}
shaders
#version 400
layout(location = 0) in vec4 vPosition;
void main()
{
gl_Position = vPosition;
}
#version 400
out vec4 fcolor;
void main()
{
fcolor = vec4(0.0, 0.0, 1.0, 1.0);
}