Cross-platform C SDK logo

Cross-platform C SDK
TUTORIAL
DEMOS
API
DOWNLOAD
BUILDS
DEVOPS
More ▼
TUTORIAL
DEMOS
API
DOWNLOAD
BUILDS
DEVOPS

Bricks

❮ Back
Next ❯
This page has been automatically translated using the Google Translate API services. We are working on improving texts. Thank you for your understanding and patience.

Briks is a very simplistic imitation of the Atari Breakout video game, which will allow us to make an introduction to the world of Synchronous applications. Any real-time application must be constantly updating whether or not the user intervenes. The source code is in folder /src/demo/bricks of the SDK distribution.

  • Use osmain_sync to start a synchronous application, indicating an interval and update callback function. NAppGUI will periodically launch time events that will update the program.
    • Game capture bricks, imitation of the Atari Breakout.
    Figure 1: Bricks video game on Windows, macOS and Linux.

This application is managed by two events (Figure 2). On the one hand the slider movement, which can occur at any time (asynchronous event), and will update the player position. On the other a synchronous event produced by osmain_sync every 40 milliseconds and will be notified through i_update() to update the game state and graphic view.

Graph showing two events, one synchronous and one asynchronous.
Figure 2: Synchronous and asynchronous events.
Listing 1: demo/bricks/bricks.c
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297

/* Simplistic Breakout-like game */

#include <nappgui.h>

#define NUM_BRICKS 40

typedef struct _brick_t Brick;
typedef struct _app_t App;

struct _brick_t
{
    real32_t x;
    real32_t y;
    uint8_t color;
    bool_t is_visible;
};

struct _app_t
{
    bool_t is_running;
    Brick bricks[NUM_BRICKS];
    color_t color[4];
    real32_t brick_width;
    real32_t player_pos;
    real32_t ball_x;
    real32_t ball_y;
    V2Df ball_dir;
    real32_t ball_speed;
    Cell *button;
    Slider *slider;
    View *view;
    Window *window;
};

/*---------------------------------------------------------------------------*/

static const real32_t i_BALL_RADIUS = .03f;
static const real32_t i_BRICK_HEIGHT = .03f;
static const real32_t i_BRICK_SEPARATION = .005f;
static const uint32_t i_BRICKS_PER_ROW = 10;
static const uint32_t i_NUM_ROWS = 4;

/*---------------------------------------------------------------------------*/

static void i_OnDraw(App *app, Event *e)
{
    const EvDraw *params = event_params(e, EvDraw);
    uint32_t i = 0;

    draw_clear(params->ctx, color_rgb(102, 153, 26));
    draw_line_color(params->ctx, kCOLOR_BLACK);

    for (i = 0; i < NUM_BRICKS; ++i)
    {
        if (app->bricks[i].is_visible == TRUE)
        {
            real32_t x = app->bricks[i].x * params->width;
            real32_t y = app->bricks[i].y * params->height;
            real32_t width = app->brick_width * params->width;
            real32_t height = i_BRICK_HEIGHT * params->height;
            draw_fill_color(params->ctx, app->color[app->bricks[i].color]);
            draw_rect(params->ctx, ekFILLSK, x, y, width, height);
        }
    }

    {
        real32_t x = (app->player_pos - app->brick_width) * params->width;
        real32_t y = (1 - i_BRICK_HEIGHT - i_BRICK_SEPARATION) * params->height;
        real32_t width = 2 * app->brick_width * params->width;
        real32_t height = i_BRICK_HEIGHT * params->height;
        draw_fill_color(params->ctx, kCOLOR_BLACK);
        draw_rect(params->ctx, ekFILL, x, y, width, height);
    }

    {
        real32_t x = app->ball_x * params->width;
        real32_t y = app->ball_y * params->height;
        real32_t rad = i_BALL_RADIUS * params->width;
        draw_fill_color(params->ctx, kCOLOR_WHITE);
        draw_circle(params->ctx, ekFILL, x, y, rad);
    }
}

/*---------------------------------------------------------------------------*/

static void i_OnSlider(App *app, Event *e)
{
    const EvSlider *params = event_params(e, EvSlider);
    app->player_pos = params->pos;
}

/*---------------------------------------------------------------------------*/

static void i_OnStart(App *app, Event *e)
{
    unref(e);
    app->is_running = TRUE;
    cell_enabled(app->button, FALSE);
}

/*---------------------------------------------------------------------------*/

 static Panel *i_panel(App *app)
 {
    Panel *panel = panel_create();
    Layout *layout = layout_create(1, 4);
    View *view = view_create();
    Slider *slider = slider_create();
    Label *label = label_create();
    Button *button = button_push();
    view_size(view, s2df(258, 344));
    view_OnDraw(view, listener(app, i_OnDraw, App));
    slider_OnMoved(slider, listener(app, i_OnSlider, App));
    label_text(label, "Use the slider!");
    button_text(button, "Start");
    button_OnClick(button, listener(app, i_OnStart, App));
    layout_view(layout, view, 0, 0);
    layout_slider(layout, slider, 0, 1);
    layout_label(layout, label, 0, 2);
    layout_button(layout, button, 0, 3);
    layout_vexpand(layout, 0);
    layout_vmargin(layout, 0, 10);
    layout_vmargin(layout, 2, 10);
    layout_margin(layout, 10);
    panel_layout(panel, layout);
    app->view = view;
    app->slider = slider;
    app->button = layout_cell(layout, 0, 3);
    return panel;
}

/*---------------------------------------------------------------------------*/

static void i_init_game(App *app)
{
    real32_t hoffset;
    Brick *brick = NULL;
    uint32_t j, i;

    app->color[0] = color_rgb(255, 0, 0);
    app->color[1] = color_rgb(0, 255, 0);
    app->color[2] = color_rgb(0, 0, 255);
    app->color[3] = color_rgb(0, 255, 255);

    hoffset = i_BRICK_SEPARATION;
    brick = app->bricks;

    app->is_running = FALSE;
    app->brick_width = (1 - ((real32_t)i_BRICKS_PER_ROW + 1) * i_BRICK_SEPARATION) / (real32_t)i_BRICKS_PER_ROW;

    for (j = 0; j < i_NUM_ROWS; ++j)
    {
        real32_t woffset = i_BRICK_SEPARATION;

        for (i = 0; i < i_BRICKS_PER_ROW; ++i)
        {
            brick->x = woffset;
            brick->y = hoffset;
            brick->is_visible = TRUE;
            brick->color = (uint8_t)j;
            woffset += app->brick_width + i_BRICK_SEPARATION;
            brick++;
        }

        hoffset += i_BRICK_HEIGHT + i_BRICK_SEPARATION;
    }

    app->player_pos = slider_get_value(app->slider);
    app->ball_x = .5f;
    app->ball_y = .5f;
    app->ball_dir.x = .3f;
    app->ball_dir.y = -.1f;
    app->ball_speed = .6f;
    v2d_normf(&app->ball_dir);
}

/*---------------------------------------------------------------------------*/

static void i_OnClose(App *app, Event *e)
{
    osapp_finish();
    unref(app);
    unref(e);
}

/*---------------------------------------------------------------------------*/

static App *i_create(void)
{
    App *app = heap_new0(App);
    Panel *panel = i_panel(app);
    app->window = window_create(ekWINDOW_STDRES);
    window_panel(app->window, panel);
    window_origin(app->window, v2df(200, 200));
    window_title(app->window, "Bricks - A 2D Game");
    window_OnClose(app->window, listener(app, i_OnClose, App));
    window_show(app->window);
    i_init_game(app);
    return app;
}

/*---------------------------------------------------------------------------*/

static void i_destroy(App **app)
{
    window_destroy(&(*app)->window);
    heap_delete(app, App);
}

/*---------------------------------------------------------------------------*/

static bool_t i_collision(Brick *brick, real32_t brick_width, real32_t ball_x, real32_t ball_y)
{
    if (ball_x + i_BALL_RADIUS < brick->x)
        return FALSE;
    if (ball_x - i_BALL_RADIUS > brick->x + brick_width)
        return FALSE;
    if (ball_y + i_BALL_RADIUS < brick->y)
        return FALSE;
    if (ball_y - i_BALL_RADIUS > brick->y + i_BRICK_HEIGHT)
        return FALSE;
    return TRUE;
}

/*---------------------------------------------------------------------------*/

static void i_update(App *app, const real64_t prtime, const real64_t ctime)
{
    if (app->is_running == TRUE)
    {
        real32_t step = (real32_t)(ctime - prtime);
        bool_t collide;
        uint32_t i;

        /* Update ball position */
        app->ball_x += step * app->ball_speed * app->ball_dir.x;
        app->ball_y += step * app->ball_speed * app->ball_dir.y;

        /* Collision with limits */
        if (app->ball_x + i_BALL_RADIUS >= 1.f && app->ball_dir.x >= 0.f)
            app->ball_dir.x = - app->ball_dir.x;

        if (app->ball_x - i_BALL_RADIUS <= 0.f && app->ball_dir.x <= 0.f)
            app->ball_dir.x = - app->ball_dir.x;

        if (app->ball_y - i_BALL_RADIUS <= 0.f && app->ball_dir.y <= 0.f)
            app->ball_dir.y = - app->ball_dir.y;

        /* Collision with bricks */
        collide = FALSE;
        for (i = 0; i < NUM_BRICKS; ++i)
        {
            if (app->bricks[i].is_visible == TRUE)
            {
                if (i_collision(&app->bricks[i], app->brick_width, app->ball_x, app->ball_y) == TRUE)
                {
                    app->bricks[i].is_visible = FALSE;
                    if (collide == FALSE)
                    {
                        real32_t brick_x = app->bricks[i].x + .5f * app->brick_width;
                        app->ball_dir.x = 5.f * (app->ball_x - brick_x);
                        app->ball_dir.y = - app->ball_dir.y;
                        v2d_normf(&app->ball_dir);
                        collide = TRUE;
                    }
                }
            }
        }

        /* Collision with player */
        {
            Brick player;
            player.x = app->player_pos - app->brick_width;
            player.y = 1.f - i_BRICK_HEIGHT - i_BRICK_SEPARATION;
            if (i_collision(&player, 2.f * app->brick_width, app->ball_x, app->ball_y) == TRUE)
            {
                app->ball_dir.x = 5.f * (app->ball_x - app->player_pos);
                app->ball_dir.y = - app->ball_dir.y;
                v2d_normf(&app->ball_dir);
            }
        }

        /* Game Over */
        if (app->ball_y + i_BALL_RADIUS >= 1.f)
        {
            i_init_game(app);
            cell_enabled(app->button, TRUE);
        }
    }

    view_update(app->view);
}

/*---------------------------------------------------------------------------*/

#include "osmain.h"
osmain_sync(.04, i_create, i_destroy, i_update, "", App)
❮ Back
Next ❯