OpenGL on Androidelf.cs.pub.ro/ndk/wiki/_media/lecture-7.pdf · I Not compatible with OpenGL ES 1.x...

OpenGL on AndroidLecture 7

Android and Low-level Optimizations Summer School

27 July 2015

This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of thislicense, visit http://creativecommons.org/licenses/by/4.0/.

OpenGL on Android, Lecture 7 1/26

OpenGL ES

OpenGL ES on Android

Demo

Debugging and Profiling

Bibliography

Keywords


Outline

OpenGL ES


Demo


Bibliography

Keywords


OpenGL ES

I Cut down version of OpenGL

I Fixed point support

I Found in many mobile platforms (Android, iOS, Blackberry,Symbian, 3DS, etc.)

I Designed for slower GPUs and CPUs

I Disclaimer: Learning OpenGL is outside the scope of thiscourse


Version 1.x

I OpenGL ES 1.0 based on OpenGL 1.3 and OpenGL ES 1.1based on OpenGL 1.5

I Common and Common-Lite (only fixed point) profile

I Fixed-function rendering pipeline

I Reduced features: no quad and polygon primitives, nostippling, only multisample AA, reduced drawing modes, nodisplay lists, etc.

I OpenGL ES 1.1 adds better multitexture support, VBOs, clipplanes, mipmap generation

I Android 1.0 and higher


Version 2.0

I Based on OpenGL 2.0, but reduced fixed-function pipelinesupport

I Not compatible with OpenGL ES 1.x

I OpenGL ES Shading Language

I ESSL only has forward branches and fixed iteration loops

I Transforming and Lighting functions replaced by shaders

I Better performance than OpenGL ES 1.x in many cases



Version 3.0

I Compatible with OpenGL ES 2.0 and OpenGL 4.3

I Standardized texture compression

I Better texturing support

I New Shading Language version with full support for integerand floating point

I Improved flow control

I Easier portability



Version 3.1

I Compatible with OpenGL ES 2.0 and 3.0

I Compute shaders

I Easier to combine shaders

I Shading language improvements

I Enhanced texturing

I Indirect draw commands



Outline

OpenGL ES


Demo


Bibliography

Keywords


GL Surface

I Manages a surface (a region of memory which can bedisplayed on screen)

I Manages an EGL display (an OpenGL rendering context)

I Dedicated rendering thread

I Can provide debug information


EGL

I Virtual display which contains a rendering context

I 2D and 3D rendering

I Allows having multiple smaller surfaces on the actual screen ordrawing to offscreen buffer

I Used by SurfaceFlinger and other compositors (Wayland, Mir)or libraries (SDL)


Outline

OpenGL ES


Demo


Bibliography

Keywords


Demo

I Turn on OpenGL in AndroidManifest.xml

I Create GL2JNIView and set it as a view for the activity

I Constructor initializes the view

p r i v a t e vo id i n i t ( boolean t r a n s l u c e n t , i n t depth , i n t s t e n c i l ) {

se tEGLContextFacto ry (new Contex tFac to r y ( ) ) ;

se tEGLConf igChoose r ( t r a n s l u c e n t ?new Conf i gChoose r (8 , 8 , 8 , 8 ,

depth , s t e n c i l ) :new Conf i gChoose r (5 , 6 , 5 , 0 ,

depth , s t e n c i l ) ) ;

s e tRend e r e r (new Rendere r ( ) ) ;}


Demo

pub l i c EGLConfig chooseCon f i g (EGL10 eg l , EGLDisplay d i s p l a y ) {/∗ Get the number o f m i n ima l l y matching EGL c o n f i g u r a t i o n s ∗/i n t [ ] num conf ig = new i n t [ 1 ] ;e g l . e g lChoo s eCon f i g ( d i s p l a y , s c o n f i g A t t r i b s 2 , nu l l ,

0 , num conf ig ) ;

i n t numConfigs = num conf ig [ 0 ] ;/∗ A l l o c a t e then read the a r r a y o f m in ima l l y

matching EGL c o n f i g s ∗/EGLConfig [ ] c o n f i g s = new EGLConfig [ numConfigs ] ;e g l . e g lChoo s eCon f i g ( d i s p l a y , s c o n f i g A t t r i b s 2 , c o n f i g s ,

numConfigs , num conf ig ) ;

/∗ Now r e t u r n the ” be s t ” one ( matches rgba s p e c i f i c a t i o n s ) ∗/r e t u r n chooseCon f i g ( eg l , d i s p l a y , c o n f i g s ) ;

}


Demo

p r i v a t e s t a t i c c l a s s Rendere r implements GLSurfaceView . Rendere r {pub l i c vo id onDrawFrame (GL10 g l ) {

GL2JNILib . s t e p ( ) ;}

pub l i c vo id onSurfaceChanged (GL10 g l , i n t width , i n t h e i g h t ) {GL2JNILib . i n i t ( width , h e i g h t ) ;

}

pub l i c vo id onSu r f a c eC rea t ed (GL10 g l , EGLConfig c o n f i g ) {// Do noth i ng .

}}


Demo

I setupGraphicsI Compiles vertex and pixel shaders into a programI Defines Uniforms, Attributes, etc.I Sets initial camera position and viewport


Demo

I renderFrameI Updates cameraI Sets shader programI Sets Uniforms and Attributes for current frameI Draws triangles


Outline

OpenGL ES


Demo


Bibliography

Keywords


Android tools

I Logging

I Debugging Developer Options: Overdraw, Clipping

I Profiling Developer Options: Performance metrics on screenor through ADB, Traces

I Tracer for OpenGL ES: Visualize traces


Tracer for OpenGL ES


Intel GPA

I Intel Atom processors

I More information: GPU, CPU, Battery usage

I More detailed analysis

I Identifies possible bottlenecks

I Realtime

I Works over Wifi


Vendor specific tools

I Low level information

I Different interface and capabilities for each vendor

I Optimizations not always portable

I PowerVR, Tegra, Adreno, etc.


Outline

OpenGL ES


Demo


Bibliography

Keywords


Bibliography

I https://www.khronos.org/opengles/

I http://developer.android.com/guide/topics/

graphics/opengl.html

I http://developer.android.com/training/graphics/

opengl/index.html


https://www.khronos.org/opengles/

http://developer.android.com/guide/topics/graphics/opengl.html

http://developer.android.com/guide/topics/graphics/opengl.html

http://developer.android.com/training/graphics/opengl/index.html

http://developer.android.com/training/graphics/opengl/index.html

Outline

OpenGL ES


Demo


Bibliography

Keywords


Keywords

I OpenGL

I EGL

I Fixed function pipeline

I Shaders

I GLSurfaceView

I Profiling

I Tracer


OpenGL on Androidelf.cs.pub.ro/ndk/wiki/_media/lecture-7.pdf · I Not compatible with OpenGL ES 1.x...

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