Object not rendering after adding transformations-CodePudding

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

However, the intended output is a spinning box with my profile picture on it. Thank you in advance for the help.

CodePudding user response：

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);