float tri_vertices[] = {-0.5f, -0.5f, 0.0f, 0.5f, -0.5f,
                        0.0f,  0.0f,  0.5f, 0.0f};
float tri_rgb_vertices[] = {
    0.5f,  -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, /**/
    -0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, /**/
    0.0f,  0.5f,  0.0f, 0.0f, 0.0f, 1.0f  /**/
};

float sqr_vertices[] = {
    0.5f,  0.5f,  0.0f, /*top R*/
    0.5f,  -0.5f, 0.0f, /*bottom R*/
    -0.5f, -0.5f, 0.0f, /*bottom L*/
    -0.5f, 0.5f,  0.0f  /*top R*/
};

unsigned int sqr_indices[] = {
    0, 1, 3, /*tl triangle*/
    1, 2, 3  /*br triangle*/
};

float sqr_tex_vertices[] = {
    /*positions*colors*texture coords*/
    0.5f,  0.5f,  0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, /*top right*/
    0.5f,  -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, /*bottom right*/
    -0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, /*bottom left*/
    -0.5f, 0.5f,  0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f  /*top left*/
};

float cube_vertices[] = {
  /*positions*texture cords*/
    -0.5f, -0.5f, -0.5f,  0.0f, 0.0f,
     0.5f, -0.5f, -0.5f,  1.0f, 0.0f,
     0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
     0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
    -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
    -0.5f, -0.5f, -0.5f,  0.0f, 0.0f,

    -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
     0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
     0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
     0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
    -0.5f,  0.5f,  0.5f,  0.0f, 1.0f,
    -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,

    -0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
    -0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
    -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
    -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
    -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
    -0.5f,  0.5f,  0.5f,  1.0f, 0.0f,

     0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
     0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
     0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
     0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
     0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
     0.5f,  0.5f,  0.5f,  1.0f, 0.0f,

    -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
     0.5f, -0.5f, -0.5f,  1.0f, 1.0f,
     0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
     0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
    -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
    -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,

    -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
     0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
     0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
     0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
    -0.5f,  0.5f,  0.5f,  0.0f, 0.0f,
    -0.5f,  0.5f, -0.5f,  0.0f, 1.0f
};

const char *basicVertexShaderSource =
    "#version 330 core\n"
    "layout (location = 0) in vec3 aPos;\n"
    "out vec3 color;\n"
    "void main()\n"
    "{\n"
    "   color = aPos;"
    "   gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
    "}\0";

const char *basicFragmentShaderSource = "#version 330 core\n"
                                        "out vec3 FragColor;\n"
                                        "in vec3 color;"
                                        "void main()\n"
                                        "{\n"
                                        "    FragColor = (color/2+.5)*1.5;\n"
                                        "}\n";

const char *rgbVertexShaderSource =
    "#version 330 core\n"
    "layout (location = 0) in vec3 aPos;\n"
    "layout (location = 1) in vec3 aColor;\n"
    "out vec3 color;\n"
    "void main()\n"
    "{\n"
    "   color = aColor;\n"
    "   gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
    "}\0";

const char *rgbFragmentShaderSource = "#version 330 core\n"
                                      "out vec4 FragColor;\n"
                                      "in vec3 color;\n"
                                      "void main()\n"
                                      "{\n"
                                      "    FragColor = vec4(color, 1.0);\n"
                                      "}\0";

const char *rgbPulseFragmentShaderSource =
    "#version 330 core\n"
    "out vec4 FragColor;\n"
    "in vec3 color;\n"
    "uniform float u_time;"
    "void main()\n"
    "{\n"
    "    FragColor = vec4(color,0.0)*(sin(u_time)/2.0+0.5);\n"
    "}\0";