minifb_game.c

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <limits.h>
#include <MiniFB.h>

#define WIDTH       800
#define HEIGHT      600
#define BOTTOM_LINE HEIGHT / 2
#define BUFSIZE     WIDTH * HEIGHT
#define SPEED       5

#define COORDTYPE   unsigned int
#define BUFTYPE     unsigned int
static const BUFTYPE color_bg = MFB_RGB(0, 0, 0);
static const BUFTYPE color_fg = MFB_RGB(255, 255, 0);
static const BUFTYPE color_ui = MFB_RGB(255, 0, 0);

struct program_state {
    COORDTYPE ppos;
    COORDTYPE last_ppos;
    unsigned char points;
    bool paused;
    bool gameover;
    bool rendering;
};


void program_state_init(struct program_state *state) {
    state->ppos = 0;
    state->last_ppos = 0;
    state->points = 0;
    state->paused = true;
    state->gameover = false;
    state->rendering = true;
}

void draw_line_h(BUFTYPE *buf, const BUFTYPE color, const COORDTYPE posx1, const COORDTYPE posy1, const COORDTYPE posx2) {
    for (COORDTYPE pos = posy1 * WIDTH + posx1; pos != posy1 * WIDTH + posx2; ++pos) {
        buf[pos] = color;
    }
}
void draw_line_v(BUFTYPE *buf, const BUFTYPE color, const COORDTYPE posx1, const COORDTYPE posy1, const COORDTYPE posy2) {
    for (COORDTYPE posy = posy1; posy != posy2 + 1; ++posy) {
        buf[posy * WIDTH + posx1] = color;
    }
}
void draw_box(BUFTYPE *buf, const BUFTYPE color, const COORDTYPE posx1, const COORDTYPE posy1, const COORDTYPE posx2, const COORDTYPE posy2) {
    draw_line_h(buf, color, posx1, posy1, posx2);
    draw_line_h(buf, color, posx1, posy2, posx2);
    draw_line_v(buf, color, posx1, posy1, posy2);
    draw_line_v(buf, color, posx2, posy1, posy2);
}

void update_buffer(BUFTYPE *buf, struct program_state *state) {
    // Draw bottom line
    draw_line_h(buf, color_fg, 0, BOTTOM_LINE, WIDTH);

    // Show gameover or pause screen if neccessary
    if (state->gameover) {
        // Count points
        state->points = 0;
        for (COORDTYPE pos = (BOTTOM_LINE - 1) * WIDTH; pos != (BOTTOM_LINE - 1) * WIDTH + WIDTH; pos += SPEED) {
            if (buf[pos] == color_fg) {
                state->points++;
            }
        }
        // Render dead frog
        draw_box(buf, color_ui, 10, 10, 100, 100);   // Left eye
        draw_box(buf, color_ui, 150, 10, 240, 100);  // Right eye
        draw_box(buf, color_ui, 10, 110, 240, 130);  // Mouth
        draw_line_h(buf, color_bg, 130, 130, 170);   // Partitial mouth line removal for tongue
        draw_box(buf, color_ui, 130, 120, 170, 200); // Tongue
        draw_line_v(buf, color_ui, 150, 120, 190);   // Tongue line
        // Stop rendering
        state->rendering = false;
        return;
    } else if (state->paused) {
        // ...
        return;
    }

    // Draw "player"
    if (state->ppos - SPEED < WIDTH) {
        draw_line_v(buf, color_bg, state->ppos - SPEED, BOTTOM_LINE - 10, BOTTOM_LINE + 10);
    }
    if (state->ppos == WIDTH) {
        state->ppos = 0;
        state->gameover = true;
    } else {
        draw_line_v(buf, color_fg, state->ppos, BOTTOM_LINE - 10, BOTTOM_LINE + 10);
        state->ppos += SPEED;
    }
}


static struct program_state prg_state;

void cb_keyboard(struct mfb_window *window, mfb_key key, mfb_key_mod mod, bool isPressed) {
    if (key == KB_KEY_ENTER && isPressed) {
        if (prg_state.ppos >= prg_state.last_ppos && prg_state.last_ppos != 0) {
            prg_state.gameover = true;
        } else {
            prg_state.points++;
        }

        prg_state.last_ppos = prg_state.ppos;
        prg_state.ppos = 0;
        prg_state.paused = false;
    }
}

int main() {
    BUFTYPE buffer[BUFSIZE];
    struct mfb_window *window = mfb_open_ex("Test!", WIDTH, HEIGHT, 0);

    if (!window) {
        perror("Failed to create window");
        return EXIT_FAILURE;
    }

    memset(buffer, color_bg, BUFSIZE * sizeof(*buffer));
    program_state_init(&prg_state);
    mfb_set_target_fps(60);

    mfb_set_keyboard_callback(window, cb_keyboard);

    while (mfb_wait_sync(window)) {
        printf("Points: %i\r", prg_state.points);

        if (prg_state.rendering) {
            update_buffer(buffer, &prg_state);
        }

        if (mfb_update(window, buffer) < 0) {
            break;
        }
    }

    return EXIT_SUCCESS;
}