[WIP] XRacer - a racing gamexracer

Plan:
-----

A simple racing game like Pole Position or Enduro.

Status:
-------
 - Currently generates a random road and scrolls through it
 - Random road generation (curves and hills)
 - Supports loading of maps from a file ("/output.xrm")
 - Sample map at http://a.pomf.se/ynhlwq.xrm

Todo:
-----
 - Convert to fixed-point math in all places (only one place left!)
 - Improve/fix track looping
 - Improve random road generation to start and end at the same height
 - Finish sprite code
 - Make sprites
 - Game-ify!

What's new:
-----------
 - NEW: uses greylib on low-depth targets!
 - Loadable maps implemented, UNTESTED!
 - Sprites in progress (see render() in graphics.c)

Change-Id: Ia2ff60b3c43d9f2e3a4f63e0ad90d2cb571c605e

1 files changed, 200 insertions, 0 deletions

diff --git a/apps/plugins/xracer/main.c b/apps/plugins/xracer/main.c
new file mode 100644
index 0000000..b0127be
--- /dev/null
+++ b/apps/plugins/xracer/main.c
@@ -0,0 +1,200 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2015 Franklin Wei
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+/*
+ * This code draws heavily on
+ * Jake Gordon's "How to build a racing game" tutorial at
+ *
+ * <http://codeincomplete.com/projects/racer/>
+ *
+ * and
+ *
+ * Louis Gorenfield's "Lou's Pseudo 3d Page" at
+ *
+ * <http://www.extentofthejam.com/pseudo/>
+ *
+ * Thanks!
+ */
+
+#include "plugin.h"
+
+#include "xracer.h"
+#include "compat.h"
+#include "generator.h"
+#include "graphics.h"
+#include "map.h"
+#include "maps.h"
+#include "road.h"
+#include "sprite.h"
+#include "util.h"
+
+#include "lib/helper.h"
+#include "lib/pluginlib_actions.h"
+#include "lib/pluginlib_exit.h"
+
+#include "fixedpoint.h" /* only used for FOV computation */
+
+/* can move to audiobuf if too big... */
+struct road_segment road[MAX_ROAD_LENGTH];
+
+/* this can be changed to allow for variable-sized maps */
+unsigned int road_length=MAX_ROAD_LENGTH;
+
+int camera_height = CAMERA_HEIGHT;
+
+void generate_test_road(void)
+{
+    gen_reset();
+    add_road(road, road_length, 0, road_length, 0, 0);
+    for(unsigned int i = 0; i < road_length; ++i)
+        add_sprite(road + i, &sprites[0]);
+}
+
+void do_early_init(void)
+{
+#ifdef HAVE_ADJUSTABLE_CPU_FREQ
+    /* GIMME DAT RAW POWAH!!! */
+    rb->cpu_boost(true);
+#endif
+
+    /* disable backlight timeout */
+    backlight_ignore_timeout();
+
+    init_alloc();
+}
+
+#if LCD_DEPTH < 4
+struct _grey_info _grey_info;
+#endif
+
+void do_late_init(void)
+{
+#if (LCD_DEPTH < 4)
+    /* greylib init */
+    size_t buf_sz = util_alloc_remaining();
+    if(!grey_init(util_alloc(buf_sz), buf_sz,
+                  GREY_BUFFERED|GREY_RAWMAPPED|GREY_ON_COP,
+                  LCD_WIDTH, LCD_HEIGHT, NULL))
+    {
+        error("grey init failed");
+    }
+    grey_show(true);
+#endif
+}
+
+enum plugin_status do_flythrough(void)
+{
+    struct camera_t camera;
+    camera.depth = camera_calc_depth(CAMERA_FOV);
+
+    LOGF("camera depth: %d", camera.depth);
+
+    camera.pos.x = 0;
+    /* y is automatically calculated */
+    camera.pos.z = 0;
+
+    //generate_test_road();
+
+    //road_length = load_map(road, MAX_ROAD_LENGTH, loop_map, ARRAYLEN(loop_map));
+
+    road_length = load_external_map(road, MAX_ROAD_LENGTH, "/output.xrm");
+
+    if(road_length == (unsigned int)-1)
+    {
+        warning("Failed to load map, using random map");
+
+        road_length = MAX_ROAD_LENGTH;
+
+        generate_random_road(road, road_length, HILLS, CURVES);
+    }
+
+    long last_timestamp = *rb->current_tick;
+
+    do_late_init();
+
+    while(1)
+    {
+        static const struct button_mapping *plugin_contexts[] = { pla_main_ctx };
+        int button = pluginlib_getaction(0, plugin_contexts, ARRAYLEN(plugin_contexts));
+        switch(button)
+        {
+        case PLA_UP:
+        case PLA_UP_REPEAT:
+            camera_height+=MANUAL_SPEED;
+            break;
+        case PLA_DOWN:
+        case PLA_DOWN_REPEAT:
+            camera_height-=MANUAL_SPEED;
+            break;
+        case PLA_LEFT:
+        case PLA_LEFT_REPEAT:
+            camera.pos.x-=MANUAL_SPEED;
+            break;
+        case PLA_RIGHT:
+        case PLA_RIGHT_REPEAT:
+            camera.pos.x+=MANUAL_SPEED;
+            break;
+        case PLA_CANCEL:
+#ifdef HAVE_ADJUSTABLE_CPU_FREQ
+            rb->cpu_boost(false);
+#endif
+            return PLUGIN_OK;
+        default:
+            exit_on_usb(button);
+            break;
+        }
+        camera.pos.z += 512;
+        /* loop the track right before going off the "end" */
+        camera.pos.z %= (road_length - DRAW_DIST) * SEGMENT_LENGTH;
+
+        render(&camera, road, road_length, camera_height);
+
+        SET_FOREGROUND(LCD_WHITE);
+        SET_BACKGROUND(LCD_BLACK);
+        int dt = *rb->current_tick - last_timestamp;
+        char buf[16];
+        //rb->snprintf(buf, sizeof(buf), "FPS: %ld", HZ/(!dt?1:dt));
+        rb->snprintf(buf, sizeof(buf), "DT: %d", dt);
+        PUTSXY(0, 0, buf);
+
+        LCD_UPDATE();
+
+        //rb->sleep((HZ/100)-dt);
+        rb->yield();
+
+        last_timestamp = *rb->current_tick;
+    }
+}
+
+/* plugin_start(): plugin entry point */
+/* contains main loop */
+enum plugin_status plugin_start(const void *param)
+{
+    (void) param;
+
+    do_early_init();
+
+    enum plugin_status rc = do_flythrough();
+#ifdef HAVE_ADJUSTABLE_CPU_FREQ
+    rb->cpu_boost(false);
+#endif
+    return rc;
+}