Function RenderScript_Clear

engine/render/src/render/render_script.cpp:1588–1643

clears the active render target * Clear buffers in the currently enabled render target with specified value. If the render target has been created with multiple * color attachments, all buffers will be cleared with the same value. * * @name render.clear * @param buffers [type:table] table with keys specifying which buffers to clear and values set to clear values. Available

     * ```
     */
    int RenderScript_Clear(lua_State* L)
    {
        RenderScriptInstance* i = RenderScriptInstance_Check(L);
        luaL_checktype(L, 1, LUA_TTABLE);

        int top = lua_gettop(L);
        (void)top;

        uint32_t flags = 0;

        dmVMath::Vector4 color(0.0f, 0.0f, 0.0f, 0.0f);
        float depth = 0.0f;
        uint32_t stencil = 0;

        lua_pushnil(L);
        while (lua_next(L, 1))
        {
            uint32_t buffer_type = luaL_checkinteger(L, -2);
            flags |= buffer_type;

            if (buffer_type == dmGraphics::BUFFER_TYPE_COLOR0_BIT)
            {
                color = *dmScript::CheckVector4(L, -1);
            }
            else if (buffer_type == dmGraphics::BUFFER_TYPE_DEPTH_BIT)
            {
                depth = (float) luaL_checkinteger(L, -1);
            }
            else if (buffer_type == dmGraphics::BUFFER_TYPE_STENCIL_BIT)
            {
                stencil = (uint32_t) luaL_checkinteger(L, -1);
            }
            else
            {
                lua_pop(L, 2);
                assert(top == lua_gettop(L));
                return luaL_error(L, "Unknown buffer type supplied to %s.clear.", RENDER_SCRIPT_LIB_NAME);
            }
            lua_pop(L, 1);
        }
        assert(top == lua_gettop(L));

        uint32_t clear_color = 0;
        clear_color |= ((uint8_t)(color.getX() * 255.0f)) << 0;
        clear_color |= ((uint8_t)(color.getY() * 255.0f)) << 8;
        clear_color |= ((uint8_t)(color.getZ() * 255.0f)) << 16;
        clear_color |= ((uint8_t)(color.getW() * 255.0f)) << 24;

        union float_to_uint32_t {float f; uint32_t i;};
        float_to_uint32_t ftoi;
        ftoi.f = depth;
        if (InsertCommand(i, Command(COMMAND_TYPE_CLEAR, flags, clear_color, ftoi.i, stencil)))
            return 0;
        else
            return luaL_error(L, "Command buffer is full (%d).", i->m_CommandBuffer.Capacity());
    }

    // Take a Lua registry reference to prevent the constant buffer