smgui/examples/draw.c

/*
 * src/draw.c
 * https://gitlab.com/bztsrc/smgui
 *
 * Copyright (C) 2024 bzt (bztsrc@gitlab), MIT license
 *
 * 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 ANY
 * DEVELOPER OR DISTRIBUTOR 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.
 *
 * @brief State-Mode GUI line draw demo program
 */

#define UI_IMPLEMENTATION
#include <ui.h>

int16_t lines[1024] = { 0 };

int main(int argc, char **argv)
{
    int x, y, lx = -1, ly = -1, btn = 0;
    char *lang[] = { "Line demo" };
    ui_event_t *evt;
    ui_t ctx;
    ui_form_t form[2] = {
        { .type = UI_LINES, .ptr = lines },
        { .type = UI_END }
    };

    (void)argc; (void)argv;

    ui_init(&ctx, 1, lang, 640, 480, NULL);

    /* wait until user closes the window */
    while((evt = ui_event(&ctx, form))) {
        /* exit on Esc */
        if(evt->type == UI_EVT_KEY && evt->key[0] == 0x1b) break;
        /* save left button pressed state */
        if(evt->type == UI_EVT_MOUSE) btn = evt->btn & UI_BTN_L;
        /* save new coordinate */
        ui_getmouse(&ctx, &x, &y);
        if(btn && x != lx && y != ly) {
            memmove(&lines[2], &lines[0], sizeof(lines) - 4 * sizeof(lines[0]));
            lines[0] = lx = x;
            lines[1] = ly = y;
            /* set color to foreground color */
            form[0].value = ctx.theme[UI_FG];
            /* let the UI know that it needs to redraw */
            ui_refresh(&ctx);
        }
    }

    ui_free(&ctx);
    return 0;
}