/**
 * Sets up the frame for drawing.
 * <some explanation here of the first part>
 * The whole screen is filled with the color supplied as arguments.
 * Letterbox is also applied here, and will share the color of the screen base.
 */
void Gfx_SetupFrame(GraphicsContext* gfxCtx, u8 r, u8 g, u8 b) {
    OPEN_DISPS(gfxCtx, "../z_rcp.c", 2386);

    gSPDisplayList(POLY_OPA_DISP++, sFillSetupDL);
    gSPDisplayList(POLY_XLU_DISP++, sFillSetupDL);
    gSPDisplayList(OVERLAY_DISP++, sFillSetupDL);

    // whats this doing?
    gDPSetScissor(POLY_OPA_DISP++, G_SC_NON_INTERLACE, 0, 0, gScreenWidth, gScreenHeight);
    gDPSetScissor(POLY_XLU_DISP++, G_SC_NON_INTERLACE, 0, 0, gScreenWidth, gScreenHeight);
    gDPSetScissor(OVERLAY_DISP++, G_SC_NON_INTERLACE, 0, 0, gScreenWidth, gScreenHeight);

    // whats this doing?
    gDPSetColorImage(POLY_OPA_DISP++, G_IM_FMT_RGBA, G_IM_SIZ_16b, gScreenWidth, gfxCtx->curFrameBuffer);
    gDPSetColorImage(POLY_OPA_DISP++, G_IM_FMT_RGBA, G_IM_SIZ_16b, gScreenWidth, gfxCtx->curFrameBuffer);
    gDPSetColorImage(POLY_XLU_DISP++, G_IM_FMT_RGBA, G_IM_SIZ_16b, gScreenWidth, gfxCtx->curFrameBuffer);
    gDPSetColorImage(OVERLAY_DISP++, G_IM_FMT_RGBA, G_IM_SIZ_16b, gScreenWidth, gfxCtx->curFrameBuffer);

    // whats this doing?
    gDPSetDepthImage(POLY_OPA_DISP++, gZBuffer);
    gDPSetDepthImage(POLY_XLU_DISP++, gZBuffer);
    gDPSetDepthImage(OVERLAY_DISP++, gZBuffer);

    if ((R_PAUSE_MENU_MODE < 2) && (gTrnsnUnkState < 2)) {
        s32 letterboxSize = Letterbox_GetSize();

        if (HREG(80) == 16) {
            if (HREG(95) != 16) {
                HREG(81) = 3;
                HREG(82) = 3;
                HREG(83) = 0;
                HREG(84) = 0;
                HREG(85) = 0;
                HREG(86) = 0;
                HREG(87) = 0;
                HREG(88) = 0;
                HREG(89) = 0;
                HREG(90) = 0;
                HREG(91) = 0;
                HREG(92) = 0;
                HREG(93) = 0;
                HREG(94) = 0;
                HREG(95) = 16;
            }

            if (HREG(81) & 1) {
                HREG(83) = letterboxSize;
            }

            if (HREG(81) & 2) {
                HREG(84) = r;
                HREG(85) = g;
                HREG(86) = b;
            }

            if (HREG(82) & 1) {
                letterboxSize = HREG(83);
            }

            if (HREG(82) & 2) {
                r = HREG(84);
                g = HREG(85);
                b = HREG(86);
            }
        }

        // Set the whole z buffer to maximum depth.
        // Dont bother with pixels that are being covered by the letterbox.
        gDPSetColorImage(POLY_OPA_DISP++, G_IM_FMT_RGBA, G_IM_SIZ_16b, gScreenWidth, gZBuffer);
        gDPSetCycleType(POLY_OPA_DISP++, G_CYC_FILL);
        gDPSetRenderMode(POLY_OPA_DISP++, G_RM_NOOP, G_RM_NOOP2);
        gDPSetFillColor(POLY_OPA_DISP++, (GPACK_ZDZ(G_MAXFBZ, 0) << 16) | GPACK_ZDZ(G_MAXFBZ, 0));
        gDPFillRectangle(POLY_OPA_DISP++, 0, letterboxSize, gScreenWidth - 1, gScreenHeight - letterboxSize - 1);
        gDPPipeSync(POLY_OPA_DISP++);

        // Fill the whole screen with the base color.
        // Dont bother with pixels that are being covered by the letterbox.
        gDPSetColorImage(POLY_OPA_DISP++, G_IM_FMT_RGBA, G_IM_SIZ_16b, gScreenWidth, gfxCtx->curFrameBuffer);
        gDPSetCycleType(POLY_OPA_DISP++, G_CYC_FILL);
        gDPSetRenderMode(POLY_OPA_DISP++, G_RM_NOOP, G_RM_NOOP2);
        gDPSetFillColor(POLY_OPA_DISP++, (GPACK_RGBA5551(r, g, b, 1) << 16) | GPACK_RGBA5551(r, g, b, 1));
        gDPFillRectangle(POLY_OPA_DISP++, 0, letterboxSize, gScreenWidth - 1, gScreenHeight - letterboxSize - 1);
        gDPPipeSync(POLY_OPA_DISP++);

        // Draw the letterbox if applicable.
        // Use the same color as the screen base.
        if (letterboxSize > 0) {
            gDPPipeSync(OVERLAY_DISP++);
            gDPSetCycleType(OVERLAY_DISP++, G_CYC_FILL);
            gDPSetRenderMode(OVERLAY_DISP++, G_RM_NOOP, G_RM_NOOP2);
            gDPSetFillColor(OVERLAY_DISP++, (GPACK_RGBA5551(r, g, b, 1) << 16) | GPACK_RGBA5551(r, g, b, 1));
            gDPFillRectangle(OVERLAY_DISP++, 0, 0, gScreenWidth - 1, letterboxSize - 1);
            gDPFillRectangle(OVERLAY_DISP++, 0, gScreenHeight - letterboxSize, gScreenWidth - 1, gScreenHeight - 1);
            gDPPipeSync(OVERLAY_DISP++);
        }
    }

    CLOSE_DISPS(gfxCtx, "../z_rcp.c", 2497);
}