backgroundLayer.c

//-------------------------------------------------------------------------
//
// The MIT License (MIT)
//
// Copyright (c) 2015 Andrew Duncan
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
//-------------------------------------------------------------------------

#include <assert.h>
#include <stdbool.h>

#include "backgroundLayer.h"

//-------------------------------------------------------------------------

void
initBackgroundLayer(
    BACKGROUND_LAYER_T *bg,
    uint16_t colour,
    int32_t layer)
{
    VC_IMAGE_TYPE_T type = VC_IMAGE_RGBA16;
    uint32_t vc_image_ptr;

    bg->resource = vc_dispmanx_resource_create(type, 1, 1, &vc_image_ptr);
    assert(bg->resource != 0);

    //---------------------------------------------------------------------

    VC_RECT_T bmp_rect;
    vc_dispmanx_rect_set(&bmp_rect, 0, 0, 1, 1);

    bg->layer = layer;

    vc_dispmanx_resource_write_data(bg->resource,
                                    type,
                                    sizeof(colour),
                                    &colour,
                                    &bmp_rect);
}

//-------------------------------------------------------------------------

void
addElementBackgroundLayer(
    BACKGROUND_LAYER_T *bg,
    DISPMANX_DISPLAY_HANDLE_T display,
    DISPMANX_UPDATE_HANDLE_T update)
{
    VC_DISPMANX_ALPHA_T alpha =
    {
        DISPMANX_FLAGS_ALPHA_FROM_SOURCE, 
        255,
        0
    };

    //---------------------------------------------------------------------

    VC_RECT_T src_rect;
    vc_dispmanx_rect_set(&src_rect, 0, 0, 1, 1);

    VC_RECT_T dst_rect;
    vc_dispmanx_rect_set(&dst_rect, 0, 0, 0, 0);

    bg->element =
        vc_dispmanx_element_add(update,
                                display,
                                bg->layer,
                                &dst_rect,
                                bg->resource,
                                &src_rect,
                                DISPMANX_PROTECTION_NONE,
                                &alpha,
                                NULL,
                                DISPMANX_NO_ROTATE);
    assert(bg->element != 0);
}

//-------------------------------------------------------------------------

void
destroyBackgroundLayer(
    BACKGROUND_LAYER_T *bg)
{
    DISPMANX_UPDATE_HANDLE_T update = vc_dispmanx_update_start(0);

    vc_dispmanx_element_remove(update, bg->element);
    vc_dispmanx_update_submit_sync(update);
    vc_dispmanx_resource_delete(bg->resource);
}