// draw a zero to destination alpha
void AppLocal::DrawScreenMask( const ovrMatrix4f & mvp, const float fadeFracX, const float fadeFracY )
{
Matrix4f mvpMatrix( mvp );
glUseProgram( OverlayScreenFadeMaskProgram.program );
glUniformMatrix4fv( OverlayScreenFadeMaskProgram.uMvp, 1, GL_FALSE, mvpMatrix.Transposed().M[0] );
if ( FadedScreenMaskSquare.vertexArrayObject == 0 )
{
FadedScreenMaskSquare = BuildFadedScreenMask( fadeFracX, fadeFracY );
}
glColorMask( 0.0f, 0.0f, 0.0f, 1.0f );
FadedScreenMaskSquare.Draw();
glColorMask( 1.0f, 1.0f, 1.0f, 1.0f );
}
// draw a zero to destination alpha
void DrawScreenMask( const ovrMatrix4f & mvp, const float fadeFracX, const float fadeFracY )
{
OVR::Matrix4f mvpMatrix( mvp );
static OVR::GlProgram prog;
if ( !prog.program )
{
prog = OVR::BuildProgram(
"uniform mat4 Mvpm;\n"
"attribute vec4 VertexColor;\n"
"attribute vec4 Position;\n"
"varying lowp vec4 oColor;\n"
"void main()\n"
"{\n"
" gl_Position = Mvpm * Position;\n"
" oColor = vec4( 1.0, 1.0, 1.0, 1.0 - VertexColor.x );\n"
"}\n"
,
"varying lowp vec4 oColor;\n"
"void main()\n"
"{\n"
" gl_FragColor = oColor;\n"
"}\n"
);
}
glUseProgram( prog.program );
glUniformMatrix4fv( prog.uMvp, 1, GL_FALSE, mvpMatrix.Transposed().M[0] );
static OVR::GlGeometry VignetteSquare;
if ( VignetteSquare.vertexArrayObject == 0 )
{
VignetteSquare = BuildFadedScreenMask( fadeFracX, fadeFracY );
}
glColorMask( 0, 0, 0, 1 );
VignetteSquare.Draw();
glColorMask( 1, 1, 1, 1 );
}
