rotating cubes differently - c++

Question

I have 25 cubes that i want to rotate each one differently this is my code on both x and y axis
i tried using rand() but it kept rotating them weirdly and all of them rotate in the same directions
this is in the game loop
for (unsigned int i = 0; i < 25; i++)
{
glm::mat4 model = glm::mat4(1.0f);
model = glm::translate(model, cubePositions[i]);
view = glm::translate(model, glm::vec3(0.0f, 0.0f, -10.0f));
float angle = 20.0f * i;
angle = glfwGetTime() * 20.0f;
model = glm::rotate(model, glm::radians(angle), glm::vec3(1.0f, 0.0f, 0.5f));
GLint modelLoc = glGetUniformLocation(ourShader.Program, "model");
glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
GLint viewLoc = glGetUniformLocation(ourShader.Program, "view");
glUniformMatrix4fv(viewLoc, 1, GL_FALSE, glm::value_ptr(view));
GLint projLoc = glGetUniformLocation(ourShader.Program, "projection");
glUniformMatrix4fv(projLoc, 1, GL_FALSE,
glm::value_ptr(projection));
glDrawArrays(GL_TRIANGLES, 0, 36);
}

Answer 1

Since there is no actual question, I try to give some comments on the posted code
that could explain the unexpected behavior of the resulting program.
The angle variable is initialised, then assigned immediately with a new
value ; only this new value is relevant, then the cubes should all rotate
at the rate of 20 degrees per second. (this is not a problem)
The view matrix is reassigned with a new value for each object! It is
extremely unlikely that this is what you want.
It's like if, while drawing a single frame, you move the camera in front of
each object being drawn ; if you move the camera and the object the same way,
then everything is displayed at the same place in the rendered frame.
(I think this is the main problem)
You should choose once for all the view matrix (as well as the projection
matrix) for the whole frame.
Some other comments, not directly related:
You should retrieve the uniform locations once for all before the loop
(and even at the beginning of the program) since they won't change as long
as you use the same shader program.
The glUniformMatrix4fv() calls for projection and view should
occur once for all before the loop; only the model matrix changes from
one object to another.
That could look like this
GLint modelLoc = glGetUniformLocation(ourShader.Program, "model");
GLint viewLoc = glGetUniformLocation(ourShader.Program, "view");
GLint projLoc = glGetUniformLocation(ourShader.Program, "projection");
glm::mat4 projection = ... already known ...
glUniformMatrix4fv(projLoc, 1, GL_FALSE, glm::value_ptr(projection));
glm::mat4 view = glm::mat4(1.0f);
// adjust to the layout of your scene
view = glm::translate(view, glm::vec3(0.0f, 0.0f, -10.0f));
glUniformMatrix4fv(viewLoc, 1, GL_FALSE, glm::value_ptr(view));
for(unsigned int i = 0; i < 25; i++)
{
glm::mat4 model = glm::mat4(1.0f);
model = glm::translate(model, cubePositions[i]);
// the same rotation rate but a different offset for each object
float angle = 20.0f * i;
angle += std::fmod(glfwGetTime() * 20.0f, 360.0f);
// choose x or y rotation axis
auto axis=(i%2) ? glm::vec3(1.0f, 0.0f, 0.0f) : glm::vec3(0.0f, 1.0f, 0.0f);
model = glm::rotate(model, glm::radians(angle), axis);
glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
glDrawArrays(GL_TRIANGLES, 0, 36);
}