├── jni
    ├── Application.mk
    ├── Android.mk
    ├── glbuffer.h
    ├── register_natives.c
    └── glbuffer.c
├── res
    ├── drawable-hdpi
    │   └── icon.png
    ├── drawable-ldpi
    │   └── icon.png
    ├── drawable-mdpi
    │   └── icon.png
    ├── values
    │   └── strings.xml
    └── layout
    │   └── main.xml
├── .gitignore
├── src
    └── com
    │   └── example
    │       └── glbuffer
    │           ├── GlBufferActivity.java
    │           └── GlBufferView.java
├── .travis.yml
├── README.mkd
├── custom_rules.xml
├── prepare-android-build.sh
├── AndroidManifest.xml
└── LICENSE


/jni/Application.mk:
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1 | APP_ABI := armeabi armeabi-v7a
2 | APP_PLATFORM := android-4
3 | 
4 | 


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/res/drawable-hdpi/icon.png:
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https://raw.githubusercontent.com/richq/glbuffer/HEAD/res/drawable-hdpi/icon.png


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/res/drawable-ldpi/icon.png:
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https://raw.githubusercontent.com/richq/glbuffer/HEAD/res/drawable-ldpi/icon.png


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/res/drawable-mdpi/icon.png:
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https://raw.githubusercontent.com/richq/glbuffer/HEAD/res/drawable-mdpi/icon.png


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/res/values/strings.xml:
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1 | <?xml version="1.0" encoding="utf-8"?>
2 | <resources>
3 |     <string name="app_name">GL Buffer Example</string>
4 | </resources>
5 | 


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/.gitignore:
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 1 | *.pyc
 2 | tags
 3 | cscope.files
 4 | cscope.in.out
 5 | cscope.out
 6 | cscope.po.out
 7 | bin/
 8 | libs/
 9 | obj/
10 | build.xml
11 | gen/
12 | local.properties
13 | proguard-project.txt
14 | project.properties
15 | 


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/jni/Android.mk:
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 1 | LOCAL_PATH := $(call my-dir)
 2 | 
 3 | BUILD_PATH := $(LOCAL_PATH)/$(SCONS_BUILD_ROOT)
 4 | 
 5 | include $(CLEAR_VARS)
 6 | 
 7 | LOCAL_LDLIBS := -llog -lGLESv1_CM
 8 | LOCAL_MODULE    := glbuffer
 9 | LOCAL_SRC_FILES := glbuffer.c register_natives.c
10 | 
11 | include $(BUILD_SHARED_LIBRARY)
12 | 


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/jni/glbuffer.h:
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 1 | #ifndef glbuffer_h_seen
 2 | #define glbuffer_h_seen
 3 | 
 4 | #include <jni.h>
 5 | #define UNUSED  __attribute__((unused))
 6 | void native_start(JNIEnv *env, jclass clazz);
 7 | void native_gl_resize(JNIEnv *env, jclass clazz, jint w, jint h);
 8 | void native_gl_render(JNIEnv *env, jclass clazz);
 9 | #endif
10 | 


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/src/com/example/glbuffer/GlBufferActivity.java:
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 1 | package com.example.glbuffer;
 2 | 
 3 | import android.app.Activity;
 4 | import android.os.Bundle;
 5 | 
 6 | public class GlBufferActivity extends Activity {
 7 | 	@Override
 8 | 	public void onCreate(Bundle savedInstanceState) {
 9 | 		super.onCreate(savedInstanceState);
10 | 		setContentView(R.layout.main);
11 | 	}
12 | }
13 | 


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/.travis.yml:
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 1 | language: android
 2 | android:
 3 |   components:
 4 |     - platform-tools
 5 |     - tools
 6 | before_install:
 7 |   - wget --timeout=30 http://dl.google.com/android/ndk/android-ndk-r8d-linux-x86.tar.bz2 -O ndk.tar.bz2
 8 |   - tar -xf ndk.tar.bz2
 9 |   - which android
10 | install: ./prepare-android-build.sh $(dirname $(dirname $(which android))) $(pwd)/android-ndk-r8d
11 | script: ant debug
12 | 


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/res/layout/main.xml:
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 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <merge xmlns:android="http://schemas.android.com/apk/res/android"
 3 |     android:layout_width="fill_parent"
 4 |     android:layout_height="fill_parent"
 5 |     >
 6 |     <com.example.glbuffer.GlBufferView
 7 |         android:id="@+id/glbuffer_view"
 8 |         android:layout_width="fill_parent"
 9 |         android:layout_height="fill_parent"/>
10 | </merge>
11 | 


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/README.mkd:
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 1 | This is a complete example of how to use GLSurfaceView and native code to draw
 2 | old-skool pixel buffer graphics on the Android platform.  It is related to this
 3 | [blog post][] about the Android NDK.
 4 | 
 5 | To compile the code:
 6 | 
 7 |     ./prepare-android-build.sh SDK [NDK]
 8 |     ant debug
 9 | 
10 | * SDK - path to the SDK (or can be set in `ANDROID_SDK`)
11 | * NDK - path to the NDK. If not given, then assumes the ndk is next to the SDK.
12 | 
13 | 
14 | [blog post]: http://quirkygba.blogspot.com/2010/10/android-native-coding-in-c.html
15 | 


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/custom_rules.xml:
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 1 | <?xml version="1.0" encoding="UTF-8"?>
 2 | <project name="custom_rules">
 3 | 
 4 |     <condition property="ndk.dir" value="${env.ANDROID_NDK}">
 5 |         <isset property="env.ANDROID_NDK" />
 6 |     </condition>
 7 |     <property name="ndk.cmd" value="ndk-build"/>
 8 |     <fail
 9 |         message="ndk.dir is missing. Set it in local.properties or inject it through the ANDROID_NDK environment variable."
10 |         unless="ndk.dir"/>
11 | 
12 |     <target name="-pre-build">
13 |         <exec executable="${ndk.dir}/${ndk.cmd}" failonerror="true">
14 |             <arg line="-j2"/>
15 |         </exec>
16 |     </target>
17 | 
18 |     <target name="-pre-clean">
19 |         <exec executable="${ndk.dir}/${ndk.cmd}" failonerror="true">
20 |             <arg line="clean"/>
21 |         </exec>
22 |     </target>
23 | </project>
24 | 


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/prepare-android-build.sh:
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 1 | #!/bin/sh
 2 | 
 3 | # prepare a build env for android in the android-build directory
 4 | 
 5 | top=$(dirname $(readlink -f $0))
 6 | cd $top
 7 | 
 8 | if test $# -eq 0 ; then
 9 |     SDK=$ANDROID_SDK
10 | elif test $# -eq 1 ; then
11 |     SDK=$1
12 | else
13 |     SDK=$1
14 |     NDK=$2
15 | fi
16 | 
17 | if test x"$SDK" = x ; then
18 |     echo "No SDK given - either set ANDROID_SDK or pass it as an argument"
19 |     exit 1
20 | fi
21 | 
22 | if test x"$NDK" = x ; then
23 |     NDK=$(ls -1d $(dirname $SDK)/android-ndk-* | tail -1)
24 | fi
25 | 
26 | exampletarget=$($SDK/tools/android list targets | awk '/android-[0-9]/{gsub("\"", ""); split($4, a, "-"); if (a[2] >= 4) { print $4}}' | head -n1)
27 | $SDK/tools/android update project -n glbuffer -p . --target $exampletarget
28 | 
29 | echo "ndk.dir=$NDK" >> local.properties
30 | 


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/AndroidManifest.xml:
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 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <manifest
 3 |     xmlns:android="http://schemas.android.com/apk/res/android"
 4 |     package="com.example.glbuffer"
 5 |     android:versionCode="1"
 6 |     android:versionName="1.0" >
 7 |     <uses-sdk
 8 |         android:targetSdkVersion="22"
 9 |         android:minSdkVersion="4" />
10 |     <application
11 |         android:icon="@drawable/icon"
12 |         android:label="@string/app_name"
13 |         android:allowBackup="true">
14 |         <activity
15 |             android:name=".GlBufferActivity"
16 |             android:label="@string/app_name">
17 |             <intent-filter>
18 |                 <action
19 |                     android:name="android.intent.action.MAIN" />
20 |                 <category
21 |                     android:name="android.intent.category.LAUNCHER" />
22 |             </intent-filter>
23 |         </activity>
24 | 
25 |     </application>
26 | </manifest>
27 | 


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/LICENSE:
--------------------------------------------------------------------------------
 1 | Copyright (c) 2011, Richard Quirk
 2 | 
 3 | Redistribution and use in source and binary forms, with or without
 4 | modification, are permitted provided that the following conditions are met:
 5 | 
 6 |    1. Redistributions of source code must retain the above copyright notice,
 7 |       this list of conditions and the following disclaimer.
 8 |    2. Redistributions in binary form must reproduce the above copyright notice,
 9 |       this list of conditions and the following disclaimer in the documentation
10 |       and/or other materials provided with the distribution.
11 | 
12 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
13 | ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
14 | WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
15 | DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
16 | FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
17 | DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
18 | SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
19 | CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
20 | OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
21 | OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
22 | 


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/jni/register_natives.c:
--------------------------------------------------------------------------------
 1 | #include <stdlib.h>
 2 | #include <stdio.h>
 3 | #include <assert.h>
 4 | #include "glbuffer.h"
 5 | 
 6 | #ifndef NELEM
 7 | #define NELEM(x) ((int)(sizeof(x) / sizeof((x)[0])))
 8 | #endif
 9 | 
10 | static const char *s_class_path_name = "com/example/glbuffer/GlBufferView";
11 | 
12 | static JNINativeMethod s_methods[] = {
13 | 	{"native_start", "()V", (void*) native_start},
14 | 	{"native_gl_resize", "(II)V", (void*) native_gl_resize},
15 | 	{"native_gl_render", "()V", (void*) native_gl_render},
16 | };
17 | 
18 | static int register_native_methods(JNIEnv* env,
19 | 		const char* class_name,
20 | 		JNINativeMethod* methods,
21 | 		int num_methods)
22 | {
23 | 	jclass clazz;
24 | 
25 | 	clazz = (*env)->FindClass(env, class_name);
26 | 	if (clazz == NULL) {
27 | 		fprintf(stderr, "Native registration unable to find class '%s'\n",
28 | 				class_name);
29 | 		return JNI_FALSE;
30 | 	}
31 | 	if ((*env)->RegisterNatives(env, clazz, methods, num_methods) < 0) {
32 | 		fprintf(stderr, "RegisterNatives failed for '%s'\n", class_name);
33 | 		return JNI_FALSE;
34 | 	}
35 | 
36 | 	return JNI_TRUE;
37 | }
38 | 
39 | static int register_natives(JNIEnv *env)
40 | {
41 | 	return register_native_methods(env,
42 | 			s_class_path_name,
43 | 			s_methods,
44 | 			NELEM(s_methods));
45 | }
46 | 
47 | jint JNICALL JNI_OnLoad(JavaVM* vm, void* reserved UNUSED)
48 | {
49 | 	JNIEnv* env = NULL;
50 | 	jint result = -1;
51 | 
52 | 	if ((*vm)->GetEnv(vm, (void**) &env, JNI_VERSION_1_4) != JNI_OK) {
53 | 		fprintf(stderr, "ERROR: GetEnv failed\n");
54 | 		goto bail;
55 | 	}
56 | 	assert(env != NULL);
57 | 
58 | 	if (register_natives(env) < 0) {
59 | 		fprintf(stderr, "ERROR: Exif native registration failed\n");
60 | 		goto bail;
61 | 	}
62 | 
63 | 	/* success -- return valid version number */
64 | 	result = JNI_VERSION_1_4;
65 | bail:
66 | 	return result;
67 | }
68 | 
69 | 


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/src/com/example/glbuffer/GlBufferView.java:
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 1 | package com.example.glbuffer;
 2 | 
 3 | import javax.microedition.khronos.opengles.GL10;
 4 | import javax.microedition.khronos.egl.EGLConfig;
 5 | import android.util.Log;
 6 | import android.opengl.GLSurfaceView;
 7 | import android.os.SystemClock;
 8 | import android.content.Context;
 9 | import android.util.AttributeSet;
10 | 
11 | public class GlBufferView extends GLSurfaceView {
12 | 	private static native void native_start();
13 | 	private static native void native_gl_resize(int w, int h);
14 | 	private static native void native_gl_render();
15 | 
16 | 	public GlBufferView(Context context, AttributeSet attrs) {
17 | 		super(context, attrs);
18 | 		(new Thread() {
19 | 			@Override
20 | 			public void run() {
21 | 				native_start();
22 | 			}
23 | 		}).start();
24 | 		setRenderer(new MyRenderer());
25 | 		requestFocus();
26 | 		setFocusableInTouchMode(true);
27 | 	}
28 | 
29 | 	class MyRenderer implements GLSurfaceView.Renderer {
30 | 		@Override
31 | 		public void onSurfaceCreated(GL10 gl, EGLConfig c) { /* do nothing */ }
32 | 
33 | 		@Override
34 | 		public void onSurfaceChanged(GL10 gl, int w, int h) {
35 | 			native_gl_resize(w, h);
36 | 		}
37 | 
38 | 		@Override
39 | 		public void onDrawFrame(GL10 gl) {
40 | 			time = SystemClock.uptimeMillis();
41 | 
42 | 			if (time >= (frameTime + 1000.0f)) {
43 | 				frameTime = time;
44 | 				avgFPS += framerate;
45 | 				framerate = 0;
46 | 			}
47 | 
48 | 			if (time >= (fpsTime + 3000.0f)) {
49 | 				fpsTime = time;
50 | 				avgFPS /= 3.0f;
51 | 				Log.d("GLBUFEX", "FPS: " + Float.toString(avgFPS));
52 | 				avgFPS = 0;
53 | 			}
54 | 			framerate++;
55 | 			native_gl_render();
56 | 		}
57 | 		public long time = 0;
58 | 		public short framerate = 0;
59 | 		public long fpsTime = 0;
60 | 		public long frameTime = 0;
61 | 		public float avgFPS = 0;
62 | 	}
63 | 
64 | 	static {
65 | 		System.loadLibrary("glbuffer");
66 | 	}
67 | }
68 | 


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/jni/glbuffer.c:
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  1 | #include <GLES/gl.h>
  2 | #include <GLES/glext.h>
  3 | #include <android/log.h>
  4 | #include <pthread.h>
  5 | #include <string.h>
  6 | #include "glbuffer.h"
  7 | 
  8 | #define TEXTURE_WIDTH 512
  9 | #define TEXTURE_HEIGHT 256
 10 | #define LOG_TAG "GLBUFEX"
 11 | #define LOGI(...)  __android_log_print(ANDROID_LOG_INFO,LOG_TAG,__VA_ARGS__)
 12 | #define S_PIXELS_SIZE (sizeof(s_pixels[0]) * TEXTURE_WIDTH * TEXTURE_HEIGHT)
 13 | #define RGB565(r, g, b)  (((r) << (5+6)) | ((g) << 6) | (b))
 14 | 
 15 | static uint16_t *s_pixels = 0;
 16 | static pthread_cond_t s_vsync_cond;
 17 | static pthread_mutex_t s_vsync_mutex;
 18 | static GLuint s_texture = 0;
 19 | static int s_x = 10;
 20 | static int s_y = 50;
 21 | 
 22 | 
 23 | static void check_gl_error(const char* op)
 24 | {
 25 | 	GLint error;
 26 | 	for (error = glGetError(); error; error = glGetError())
 27 | 		LOGI("after %s() glError (0x%x)\n", op, error);
 28 | }
 29 | 
 30 | /* wait for the screen to redraw */
 31 | static void wait_vsync()
 32 | {
 33 | 	pthread_mutex_lock(&s_vsync_mutex);
 34 | 	pthread_cond_wait(&s_vsync_cond, &s_vsync_mutex);
 35 | 	pthread_mutex_unlock(&s_vsync_mutex);
 36 | }
 37 | 
 38 | static void render_pixels(uint16_t *pixels)
 39 | {
 40 | 	int x, y;
 41 | 	/* fill in a square of 5 x 5 at s_x, s_y */
 42 | 	for (y = s_y; y < s_y + 5; y++) {
 43 | 		for (x = s_x; x < s_x + 5; x++) {
 44 | 			int idx = x + y * TEXTURE_WIDTH;
 45 | 			pixels[idx++] = RGB565(31, 31, 0);
 46 | 		}
 47 | 	}
 48 | }
 49 | 
 50 | int s_w = 0;
 51 | int s_h = 0;
 52 | 
 53 | /* disable these capabilities. */
 54 | static GLuint s_disable_caps[] = {
 55 | 	GL_FOG,
 56 | 	GL_LIGHTING,
 57 | 	GL_CULL_FACE,
 58 | 	GL_ALPHA_TEST,
 59 | 	GL_BLEND,
 60 | 	GL_COLOR_LOGIC_OP,
 61 | 	GL_DITHER,
 62 | 	GL_STENCIL_TEST,
 63 | 	GL_DEPTH_TEST,
 64 | 	GL_COLOR_MATERIAL,
 65 | 	0
 66 | };
 67 | 
 68 | void native_gl_resize(JNIEnv *env UNUSED, jclass clazz UNUSED, jint w, jint h)
 69 | {
 70 | 	LOGI("native_gl_resize %d %d", w, h);
 71 | 	glDeleteTextures(1, &s_texture);
 72 | 	GLuint *start = s_disable_caps;
 73 | 	while (*start)
 74 | 		glDisable(*start++);
 75 | 	glEnable(GL_TEXTURE_2D);
 76 | 	glGenTextures(1, &s_texture);
 77 | 	glBindTexture(GL_TEXTURE_2D, s_texture);
 78 | 	glTexParameterf(GL_TEXTURE_2D,
 79 | 			GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 80 | 	glTexParameterf(GL_TEXTURE_2D,
 81 | 			GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 82 | 	glShadeModel(GL_FLAT);
 83 | 	check_gl_error("glShadeModel");
 84 | 	glColor4x(0x10000, 0x10000, 0x10000, 0x10000);
 85 | 	check_gl_error("glColor4x");
 86 | 	int rect[4] = {0, TEXTURE_HEIGHT, TEXTURE_WIDTH, -TEXTURE_HEIGHT};
 87 | 	glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_CROP_RECT_OES, rect);
 88 | 	check_gl_error("glTexParameteriv");
 89 | 	s_w = w;
 90 | 	s_h = h;
 91 | }
 92 | 
 93 | void native_gl_render(JNIEnv *env UNUSED, jclass clazz UNUSED)
 94 | {
 95 | 	memset(s_pixels, 0, S_PIXELS_SIZE);
 96 | 	render_pixels(s_pixels);
 97 | 	glClear(GL_COLOR_BUFFER_BIT);
 98 | 	glTexImage2D(GL_TEXTURE_2D,		/* target */
 99 | 			0,			/* level */
100 | 			GL_RGB,			/* internal format */
101 | 			TEXTURE_WIDTH,		/* width */
102 | 			TEXTURE_HEIGHT,		/* height */
103 | 			0,			/* border */
104 | 			GL_RGB,			/* format */
105 | 			GL_UNSIGNED_SHORT_5_6_5,/* type */
106 | 			s_pixels);		/* pixels */
107 | 	check_gl_error("glTexImage2D");
108 | 	glDrawTexiOES(0, 0, 0, s_w, s_h);
109 | 	check_gl_error("glDrawTexiOES");
110 | 	/* tell the other thread to carry on */
111 | 	pthread_cond_signal(&s_vsync_cond);
112 | }
113 | 
114 | void native_start(JNIEnv *env UNUSED, jclass clazz UNUSED)
115 | {
116 | 	/* init conditions */
117 | 	pthread_cond_init(&s_vsync_cond, NULL);
118 | 	pthread_mutex_init(&s_vsync_mutex, NULL);
119 | 	int incr = 1;
120 | 	s_pixels = malloc(S_PIXELS_SIZE);
121 | 	while (1) {
122 | 		/* draw a square going backwards and forwards */
123 | 		s_x += incr;
124 | 		if (s_x > 200)
125 | 			incr = -1;
126 | 		if (s_x < 20 && incr < 0)
127 | 			incr = 1;
128 | 		/* wait on screen sync */
129 | 		wait_vsync();
130 | 	}
131 | }
132 | 


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