ui_display_brs.c

/*
 * Copyright 2023-2026 MicroEJ Corp. All rights reserved.
 * MicroEJ Corp. PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 * Build: 7E4D1F7C
 */
 
/*
 * @file
 * @brief This file implements is the common part of all display buffer strategies (BRS).
 * @author MicroEJ Developer Team
 * @version 14.5.5
 */
 
// --------------------------------------------------------------------------------
// Includes
// --------------------------------------------------------------------------------
 
#include <string.h>
 
#include "ui_display_brs.h"
#include "bsp_util.h"
#include "ui_drawing.h"
 
// --------------------------------------------------------------------------------
// ui_display_brs.h API
// --------------------------------------------------------------------------------
 
/*
 * @brief Provides a simple implementation of the restore: use memcpy().
 * See the header file for the function documentation
 */
BSP_DECLARE_WEAK_FCNT DRAWING_Status UI_DISPLAY_BRS_restore(MICROUI_GraphicsContext *gc, MICROUI_Image *old_back_buffer,
                                                            ui_rect_t *rect) {
    DRAWING_Status ret;
    uint32_t bpp = LLUI_DISPLAY_getImageBPP(old_back_buffer);
    uint32_t width = UI_RECT_get_width(rect);
    uint32_t height = UI_RECT_get_height(rect);
 
    if (8u > bpp) {
        // this weak function is not designed to target this kind of buffer
        // -> let the standard function copyImage() performing the job
        ret = UI_DRAWING_copyImage(gc, old_back_buffer, rect->x1, rect->y1, width, height, rect->x1, rect->y1);
    } else {
        uint8_t *dst = LLUI_DISPLAY_getBufferAddress(&gc->image);
        uint8_t *src = LLUI_DISPLAY_getBufferAddress(old_back_buffer);
        uint32_t stride = LLUI_DISPLAY_getStrideInBytes(&gc->image);
 
        dst += rect->y1 * stride;
        src += rect->y1 * stride;
 
        if ((0 == rect->x1) && (old_back_buffer->width == width)) {
            // a simple memcpy is required!
            (void)memcpy(dst, src, stride * height);
        } else {
            // have to perform one memcpy per line
            dst += rect->x1 * bpp / 8u;
            src += rect->x1 * bpp / 8u;
            uint32_t size = width * bpp / 8u;
 
            for (uint32_t y = 0; y < height; y++) {
                (void)memcpy(dst, src, size);
                dst += stride;
                src += stride;
            }
        }
 
        // the memcpy() above draws in the back buffer with the CPU, so it is notified like any other
        // software drawing: on a VEE port whose buffers sit in a cached memory, the next drawing may be a
        // GPU one and it has to flush the cache first. The bpp < 8 branch above needs no notification:
        // UI_DRAWING_copyImage() notifies by itself when it falls back to software.
        LLUI_DISPLAY_IMPL_notifyDrawingSoft(gc);
 
        ret = DRAWING_DONE;
    }
    return ret;
}
 
// --------------------------------------------------------------------------------
// EOF
// --------------------------------------------------------------------------------