Render passes

Every draw call in modkit belongs to a pass. A pass owns a render target, a clear state and a view/projection pair, and bgfx sorts submissions by the pass’s view id.

The implicit pass

For simple cases there is nothing to set up. mk_clear opens the default pass against the backbuffer:

static void frame(void* user_data) {
    (void)user_data;
    mk_clear(MK_RGBA(0x11, 0x11, 0x14, 0xff));
    mk_draw3d_cube((mk_vec3){0, 0, 0}, 1.0f, MK_RGBA(0x5f, 0x6f, 0xd8, 0xff));
}

Explicit passes

Once you have more than one target — a shadow map, an offscreen buffer, a post chain — open passes yourself:

mk_pass_desc desc = {
    .target      = shadow_target,
    .clear_flags = MK_CLEAR_DEPTH,
    .view        = light_view,
    .projection  = light_proj,
};

mk_pass_t pass = mk_pass_begin(&desc);
    draw_scene_geometry();
mk_pass_end(pass);

Passes are submitted in the order they are begun. Anything drawn between begin and end belongs to that pass, and resource creation is main-thread-only — see pass.h for the full surface.

The same thing from TypeScript

const pass = runtime.beginPass({ clearColor: '#111114' });
pass.draw({ geometry, material, position: [0, 0, 0] });
runtime.finishPass(pass);

The JS binding mirrors the C model rather than inventing its own, so a pass means the same thing in both. See the JavaScript guides for demos that run on the page.