ctx.expectError(GL_NO_ERROR);
ctx.glBlendEquation(getEquation(s_equations[ndx]));
ctx.glDrawElements(GL_TRIANGLES, 0, GL_UNSIGNED_INT, 0);
ctx.expectError(GL_NO_ERROR);
ctx.glBlendEquation(getEquation(s_equations[ndx]));
ctx.glDrawElements(GL_TRIANGLES, 0, GL_UNSIGNED_INT, 0);