Strange error with QGLFunctions

[Zamaster]

So I fixed this issue by extending out to QOpenGLFunctions instead of QGLFunctions and calling makeCurrent() and initializeOpenGLFunctions in initializeGL(). Now I've run into the issue that my OpenGL code seems to flop, as in it won't draw anything but a black screen. Any takers?

Updated myglwidget.cpp

#include "myglwidget.h"
#include <QDebug>
#include <QVector3D>
#include <QVector2D>
#include "locale.h"
 
 
#define BACK_TILE_S 48
 
struct VertexData
{
    QVector3D position;
    QVector2D texCoord;
};
 
MyGLWidget::MyGLWidget(QWidget *parent) :
    QGLWidget(parent)
{
 
}
 
MyGLWidget::~MyGLWidget(){
    glDeleteBuffers(2, vboid);
}
 
void MyGLWidget::initializeGL(){
    VertexData verts[] = {
            {QVector3D(0, 0, 0), QVector2D(0, 0)},
            {QVector3D(1, 0, 0), QVector2D(1, 0)},
            {QVector3D(0, 1, 0), QVector2D(0, 1)},
            {QVector3D(1, 1, 0), QVector2D(1, 1)}
    };
    GLushort indices[] = {
        0, 1, 2, 3
    };
    makeCurrent();
    initializeOpenGLFunctions();
 
    setlocale(LC_NUMERIC, "C");
 
    default_prog.addShaderFromSourceFile(QGLShader::Vertex, ":/shaders/default.vert");
    default_prog.addShaderFromSourceFile(QGLShader::Fragment, ":/shaders/default.frag");
    default_prog.link();
 
    default_prog.bind(); // this is in initgl since this is the
                         // only shader we use... FOR NOW, therefore
                         // we dont have to do it elsewhere
    setlocale(LC_ALL, "");
 
    glDisable(GL_DEPTH_TEST);
    glEnable(GL_TEXTURE_2D);
    // normally here we would have the QImage buffered up already
    // and would bind as needed, but again, this is the only
    // texture we use for now
    back_texture = bindTexture(QImage(":/gfx/gfx/back.png"));
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 
 
    glGenBuffers(2, vboid);
 
    glBindBuffer(GL_ARRAY_BUFFER, vboid[0]);
    glBufferData(GL_ARRAY_BUFFER, 4 * sizeof(VertexData), verts, GL_STATIC_DRAW);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vboid[1]);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, 4 * sizeof(GLushort), indices, GL_STATIC_DRAW);
 
}
 
void MyGLWidget::paintGL(){
    int texw;
    int texh;
    QMatrix4x4 proj;
    QMatrix2x2 scale;
    quintptr offset;
    int vertexLoc;
    int texcoordLoc;
 
    texw = (floor(width / ((double) BACK_TILE_S)) + 1);
    texh = (floor(height / ((double) BACK_TILE_S)) + 1);
 
    proj.setToIdentity();
    proj.scale(texw * BACK_TILE_S, texh * BACK_TILE_S);
    proj.ortho(0, width, 0, height, -1, 1);
 
    scale.setToIdentity();
    scale(0,0) = texw;
    scale(1,1) = texh;
 
    default_prog.setUniformValue("texScale", scale);
    default_prog.setUniformValue("mvp_matrix", proj);
    default_prog.setUniformValue("texture", 0);
 
    glBindBuffer(GL_ARRAY_BUFFER, vboid[0]);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vboid[1]);
 
    offset = 0;
 
    vertexLoc = default_prog.attributeLocation("a_position");
    default_prog.enableAttributeArray(vertexLoc);
    glVertexAttribPointer(vertexLoc, 3, GL_FLOAT, GL_FALSE, sizeof(VertexData), (const void*) offset);
 
    offset += sizeof(QVector3D);
 
    texcoordLoc = default_prog.attributeLocation("a_texcoord");
    default_prog.enableAttributeArray(texcoordLoc);
    glVertexAttribPointer(texcoordLoc, 2, GL_FLOAT, GL_FALSE, sizeof(VertexData), (const void*) offset);
 
    glDrawElements(GL_TRIANGLE_STRIP, 4, GL_UNSIGNED_SHORT, 0);
 
}
 
 
void MyGLWidget::resizeGL(int width, int height){
    this->width = width;
    this->height = height;
}

#include "myglwidget.h"
#include <QDebug>
#include <QVector3D>
#include <QVector2D>
#include "locale.h"


#define BACK_TILE_S 48

struct VertexData
{
    QVector3D position;
    QVector2D texCoord;
};

MyGLWidget::MyGLWidget(QWidget *parent) :
    QGLWidget(parent)
{

}

MyGLWidget::~MyGLWidget(){
    glDeleteBuffers(2, vboid);
}

void MyGLWidget::initializeGL(){
    VertexData verts[] = {
            {QVector3D(0, 0, 0), QVector2D(0, 0)},
            {QVector3D(1, 0, 0), QVector2D(1, 0)},
            {QVector3D(0, 1, 0), QVector2D(0, 1)},
            {QVector3D(1, 1, 0), QVector2D(1, 1)}
    };
    GLushort indices[] = {
        0, 1, 2, 3
    };
    makeCurrent();
    initializeOpenGLFunctions();

    setlocale(LC_NUMERIC, "C");

    default_prog.addShaderFromSourceFile(QGLShader::Vertex, ":/shaders/default.vert");
    default_prog.addShaderFromSourceFile(QGLShader::Fragment, ":/shaders/default.frag");
    default_prog.link();

    default_prog.bind(); // this is in initgl since this is the
                         // only shader we use... FOR NOW, therefore
                         // we dont have to do it elsewhere
    setlocale(LC_ALL, "");

    glDisable(GL_DEPTH_TEST);
    glEnable(GL_TEXTURE_2D);
    // normally here we would have the QImage buffered up already
    // and would bind as needed, but again, this is the only
    // texture we use for now
    back_texture = bindTexture(QImage(":/gfx/gfx/back.png"));
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);


    glGenBuffers(2, vboid);

    glBindBuffer(GL_ARRAY_BUFFER, vboid[0]);
    glBufferData(GL_ARRAY_BUFFER, 4 * sizeof(VertexData), verts, GL_STATIC_DRAW);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vboid[1]);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, 4 * sizeof(GLushort), indices, GL_STATIC_DRAW);

}

void MyGLWidget::paintGL(){
    int texw;
    int texh;
    QMatrix4x4 proj;
    QMatrix2x2 scale;
    quintptr offset;
    int vertexLoc;
    int texcoordLoc;

    texw = (floor(width / ((double) BACK_TILE_S)) + 1);
    texh = (floor(height / ((double) BACK_TILE_S)) + 1);

    proj.setToIdentity();
    proj.scale(texw * BACK_TILE_S, texh * BACK_TILE_S);
    proj.ortho(0, width, 0, height, -1, 1);

    scale.setToIdentity();
    scale(0,0) = texw;
    scale(1,1) = texh;

    default_prog.setUniformValue("texScale", scale);
    default_prog.setUniformValue("mvp_matrix", proj);
    default_prog.setUniformValue("texture", 0);

    glBindBuffer(GL_ARRAY_BUFFER, vboid[0]);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vboid[1]);

    offset = 0;

    vertexLoc = default_prog.attributeLocation("a_position");
    default_prog.enableAttributeArray(vertexLoc);
    glVertexAttribPointer(vertexLoc, 3, GL_FLOAT, GL_FALSE, sizeof(VertexData), (const void*) offset);

    offset += sizeof(QVector3D);

    texcoordLoc = default_prog.attributeLocation("a_texcoord");
    default_prog.enableAttributeArray(texcoordLoc);
    glVertexAttribPointer(texcoordLoc, 2, GL_FLOAT, GL_FALSE, sizeof(VertexData), (const void*) offset);

    glDrawElements(GL_TRIANGLE_STRIP, 4, GL_UNSIGNED_SHORT, 0);

}


void MyGLWidget::resizeGL(int width, int height){
    this->width = width;
    this->height = height;
}

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default.vert

#version 150
 
uniform mat4x4 mvp_matrix;
uniform mat2x2 texScale;
 
in vec4 a_position;
in vec2 a_texcoord;
 
out vec2 v_texcoord;
 
void main() {
    v_texcoord = a_texcoord * texScale;
    gl_Position = mvp_matrix * a_position;
}

#version 150

uniform mat4x4 mvp_matrix;
uniform mat2x2 texScale;

in vec4 a_position;
in vec2 a_texcoord;

out vec2 v_texcoord;

void main() {
    v_texcoord = a_texcoord * texScale;
    gl_Position = mvp_matrix * a_position;
}

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default.frag

#version 150
 
uniform sampler2D texture;
 
in vec2 v_texcoord;
 
void main()
{
    gl_FragColor = texture2D(texture, v_texcoord);
}

#version 150

uniform sampler2D texture;

in vec2 v_texcoord;

void main()
{
    gl_FragColor = texture2D(texture, v_texcoord);
}

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