Object not rendering after adding transformations - c

Question

I'm adding transformations to my C OpenGL program. I'm using CGLM as my maths library. The program has no warnings or errors. Still however, when I compile and run the program, I simply get a window coloured my clear colour. The following is my program's main loop
// Initialize variables for framerate counting
double lastTime = glfwGetTime();
int frameCount = 0;
// Program loop
while (!glfwWindowShouldClose(window)) {
// Calculate framerate
double thisTime = glfwGetTime();
frameCount++;
// If a second has passed.
if (thisTime - lastTime >= 1.0) {
printf("%i FPS\n", frameCount);
frameCount = 0;
lastTime = thisTime;
}
processInput(window);
// Clear the window
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
// Bind textures on texture units
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, texture2);
// Create transformations
mat4 transform = {{1.0f}};
glm_translate(transform, (vec3){0.5f, -0.5f, 0.0f});
glm_rotate(transform, (float)glfwGetTime(), (vec3){0.0f, 0.0f, 1.0f});
printf("%i\n", transform);
// Get matrix's uniform location and set matrix
shaderUse(myShaderPtr);
GLint transformLoc = glGetUniformLocation(myShaderPtr->shaderID, "transform");
printf("%i\n", transformLoc);
glUniformMatrix4fv(transformLoc, 1, GL_FALSE, *transform);
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
glfwSwapBuffers(window); // Swap the front and back buffers
glfwPollEvents(); // Check for events (mouse movement, mouse click, keyboard press, keyboard release etc.)
}
The Program is up on github here if you'd like to check out the full code.
The output of this program is
However, the intended output is a spinning box with my profile picture on it.

Answer 1

mat4 transform = {{1.0f}}; does not do what you expect. C doesn't have a constructor like C++. The C++ version's constructor initialized the matrix with the Identity matrix. You have to use glm_mat4_identity to initialize with the identity matrix:
mat4 transform;
glm_mat4_identity(transform);
glm_rotate(transform, (float)glfwGetTime(), (vec3){0.0f, 0.0f, 1.0f});
glUniformMatrix4fv(transformLoc, 1, GL_FALSE, (float*)transform);
Additionally, you need to specify and add an orthographic projection matrix that compensates for the aspect ratio of the viewport:
float aspect = (float)width / (float)height;
mat4 projection;
glm_ortho(-aspect, aspect, -1.0f, 1.0f, -1.0f, 1.0f, projection)
mat4 transform;
glm_rotate(transform, (float)glfwGetTime(), (vec3){0.0f, 0.0f, 1.0f});
glm_mat4_identity(transform);
mat4 mvp;
glm_mat4_mul(projection, transform, mvp);
GLint transformLoc = glGetUniformLocation(myShaderPtr->shaderID, "transform");
glUniformMatrix4fv(transformLoc, 1, GL_FALSE, (float*)mvp);