2D OpenGL in GLFW flickers - c++

Question

I'm trying to create a 2D game using OpenGL. My helper libraries are GLFW, GLEW, SOIL (for images) and glm (for maths).
I've managed to draw a rectangle with a very simple texture on it. But when I try to move this rectangle it frequently has a little flicker (the timer between flickers is almost always the same), and the faster I move it, the more visible it becomes.
Another problem I have is I'm working on a laptop, and it renders fine with my integrated graphics (fine as in it works, it still stutters) but when I execute my program with my Nvidia graphics card it just shows my clearcolor, and nothing else, which is extremely odd. My sprite translation happens in the runCallback code (called in the main loop) and is just a multiplication of matrices. The result matrix is then fetched and used in the draw code. In the drawCallback theres just the DrawSprite function being called. Also I should note I'm using OpenGL 3.3 .
I'm sorry in advance for the rather large amount of code, but after extensive testing and trying a multitude of things i have no idea where my mistake lies...
If you would like to help me but need any more information, i will provide.
UPDATE:
Problem with Nvidia graphics card resolved, it was due to a wrong uniform parameter. But the stutter remains.
IMAGE LOADING CODE
SD_Texture::SD_Texture(const char * fileName)
{
texture = new GLuint;
unsigned char* data = SOIL_load_image(fileName, &width, &height, 0, SOIL_LOAD_RGB);
glGenTextures(1, (GLuint*)texture);
glBindTexture(GL_TEXTURE_2D, *((GLuint*)(texture)));
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, 0);
SOIL_free_image_data(data);
}
void SD_Texture::Bind()
{
glBindTexture(GL_TEXTURE_2D, *(GLuint*)texture);
}
VAO SETUP CODE
void SD_Window::SetupVAO()
{
GLfloat vertices[] =
{
-0.5f, 0.5f, 0.0f, 0.0f, 1.0f,
-0.5f, -0.5f, 0.0f, 0.0f, 0.0f,
0.5f, -0.5, 0.0f, 1.0, 0.0f,
-0.5f, 0.5f, 0.0f, 0.0f, 1.0f,
0.5f, -0.5f, 0.0f, 1.0f, 0.0f,
0.5f, 0.5f, 0.0f, 1.0f, 1.0f
};
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GL_FLOAT), (GLvoid*)nullptr);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GL_FLOAT), (GLvoid*)(3 * sizeof(GLfloat)));
glBindVertexArray(0);
}
DRAW CODE
void SD_Window::DrawSprite(SD_Sprite * sprite)
{
glActiveTexture(GL_TEXTURE0);
sprite->GetTexture()->Bind();
glUniformMatrix4fv(transformUniform, 1, GL_FALSE, glm::value_ptr(ortho * sprite->GetTransform()));
glBindVertexArray(VAO);
glDrawArrays(GL_TRIANGLES, 0, 6);
glBindVertexArray(0);
glBindTexture(GL_TEXTURE_2D, 0);
}
MAIN LOOP CODE
void SD_Window::TakeControl(void (*runCallback)(float delta), void (*drawCallback)())
{
double currentTime;
double oldTime = 0.0f;
while (!ShouldClose())
{
currentTime = glfwGetTime();
glClear(GL_COLOR_BUFFER_BIT);
drawCallback();
glfwSwapBuffers(window);
runCallback(currentTime - oldTime);
oldTime = currentTime;
glfwPollEvents();
}
glfwDestroyWindow(window);
glfwTerminate();
}
VERTEX SHADER
#version 330 core
layout (location = 0) in vec3 position;
layout (location = 1) in vec2 texCoord;
out vec2 sCoord;
uniform mat4 transform;
void main()
{
gl_Position = transform * vec4(position, 1.0f);
sCoord = vec2(texCoord.x, 1.0f - texCoord.y);
}
FRAGMENT SHADER
#version 330 core
in vec2 sCoord;
out vec4 color;
uniform sampler2D sTexture;
void main()
{
color = texture(sTexture, sCoord);
}