const char* k3DClearBitmapVS = R"(#version 140

in vec2 vPosition;

smooth out vec2 fTexcoord;

void main()
{
    fTexcoord = (vPosition + 1.0) * vec2(0.5, 0.375);
    gl_Position = vec4(vPosition, 0.0, 1.0);
}
)";
