Configuring BaCon (Raspberry Pi 2 , RASPBIAN)

[alexfish]

Hi All

Configuring Bacon for Raspbian on Raspberry Pi 2

Possible easy route for Beginners,

1. install synaptic , this also brings in quite a few of the neccessities for developement work and not just for bacon
from the terminal
sudo apt-get install synaptic

using synaptic::

1.2 update the system using synaptic

Note :: did a test of mobile internet 3g/4g. You may find the dongle will not register + the mouse will freeze
as a work around , plug a usb memory stick in first , unplug the memory stick , plug the mobile dongle .

after updating the system reboot . the dongle should now hot plug. esp if have usb_modeswitch + ppp + wvdial Installed

2. install build-essentials
3. install gtk sourceview3 devs if wanting to use gtk3 or can just try gtk sourceview2 devs this also brings in some neccesities for development work.
+ the neccessary libs for hug.bac
4. install xterm

download Autoconf source package BaCon 3.1 from HERE

Extract the tar file

from the terminal

cd to the bacon folder

./configure
make
sudo make install

also need latest hug.bac
make folder in home/pi/ named bacon
cd /home/pi/bacon/
wget http://www.basic-converter.org/hug.bac
for html helpfiles
wget http://www.basic-converter.org/documentation.html
Reboot

one should be able to find Bacongui in Menu/Programming . the sytaxfile file should auto download.

reboot the gui.

to read documentation ::

use the file browser , go to the bacon folder and Click on

documentation.html

hopeful on system there is a web browser call Dillo . this will show the documentation..
a quick demo.

testhug.bac .. save as '/home/pi/bacon/testhug.bac

INCLUDE hug.bac


SUB Click()

PRINT "Button Clicked"

END SUB

win = WINDOW("test", 600,400)
but = BUTTON("test-but",100,25)
ATTACH(win,but,10,10)
CALLBACK(but,Click)


Note :: canvas gl and gl area will not work .. Rasberry pi 2 is configured for GL ES . ie gl is implemented direct on the GPU .
best beginners option will be to install goocanvas . then see " thread goo canvas."

have posted blow a link to the gl es book examples:: further to this there should be a folder call " vc " in the /opt/ IE path /opt/vc

Copy this to the bacon folder. cd to the folder
cd /baco/vc/src/hello_pi
then enter command
./rebuild.sh

Ok. check the execs.. and esp this one "hello_triangle" & for display of speed rendering "hello_triangle2"

triangle2 is a combination of mandelbrot/julia sets . amazing.

down to hard nuts:: one will need to use some communication with X11 , to safely exit the demo code .

at present one has to use ctrl + c to get out of the loop.

Bacon can do this . make a window full size of the screen.. now can convert the c code to bacon using the useh for the header files
+ Usec for the c defs that U not be sure of .

main objective here :: in the sources there is a method to free the bits : us the KEY() command .. on KEY() = <x> : >> call a sub that contains the Free's

now U be in control ..

Hint:: make a sub that builds the GL ES window , place a Button with callback to the SUB which makes the GL ES window etc etc.,
Same for button to exit.. "END" or "QUIT"
also set the main gles window alpha value to 0 IE::
glClearColor(0.15f, 0.25f, 0.35f, 0.0f)

[vovchik]

Dear Alex,

I see what you have been up to. Wish I had a raspberry PI to test. One of these days....

With kind regards,
vovchik

[alexfish]

Hi All & @ 1 for Peter

here is a how to compile tcc from source package

download tcc from HERE

extract the file then cd to the folder

from the terminal

./configure --with-libgcc

make

sudo make install

now a one for @ Peter :: using latest beta . ?

BaCon err = can not find lib bacon

yet if compile with the -a :: make ar then it will compile. but need to do so on every compile . have the bacon ar in usr/local/lib + usr/lib ??

however have tested terminal mode + the hug.bac demo as above + tested GooCanvas + the list which uses scrolled win

This is looking good .if can resolve the archive rebuild.

BR
Alex

PS: the hug demo above :: tcc 6 to 7 seconds | gcc 16 seconds

[Pjot]

Hi Alex,

It seems you have to add the location of 'libbacon.a' explicitly. For example:

# bacon -c tcc -l -L/usr/local/lib prog.bac

Here, the '-l' flag has "-L/usr/local/lib" as argument, which points to the directory where 'libbacon.a' resides on my system.

BR
Peter

[alexfish]

Hi Peter

The code above works,

+ one can enter this is the bacongui options at compile time

enter this code in Libraries
-lbacon -L/usr/local/lib

BR
Alex

[alexfish]

Hi Al

For those interest the fb and gles side of things, there is an easy api to gain access to gles
Should make life easier to convert to Bacon ?

If system up to date can ignore the Fix in the readme . Raspbian only

in Raspbian the main bits should be configured :: RE :: if followed the above posts.

will find via synaptic.
libraspberrypi-dev
EGL/GLES/OpenVG/etc. libraries for the Raspberry Pi's VideoCore IV (headers)

the master is in c. but will give a taste of what can be done .
and will see Raspberry Pi 2 is no slow coach

make a folder in downloads called opengles

then from the terminal

cd /home/pi/Downloads/opengles
wget --no-check-certificate https://github.com/benosteen/opengles-book-samples/tarball/master
tar -xvzf master
cd /home/pi/Downloads/opengles/benosteen-opengles-book-samples-5ff2dc9/Raspi
make

Note :do not try achiver on the master:: You have been warned

can also have a look at Linux volume if on standard desktop IE Intel, Amd etc , there is also an Anroid version

boot the Task Manager in the Accessories

go to each folder and click on the exec's , to stop the app look in the task manager . click on the app and kill it.

BR
Alex

[alexfish]

Just a quote

Sorry this is not technically critical but - WOW!

? is convergence a reality

I have seen a Yes....

EGL...

BR
Alex

[alexfish]

Hi All

have been going through the book examples + the demo's in the VC folder

As for the VC folder , reference to the Open-gles + the Egl , these libs should be common to most devices like the Raspberry Pi + pads and phones etc

have found that there are some bugs in the shader + the texture examples , where by Gcc will not compile some of the demo's due to incompatible pointer types..

not exactly sure what they are , as a brief look indicates they of of the correct type , need to dig deeper.

Tcc will compile them , if have the compiled version as per earlier Post. tcc will only post a warning on the 'CUBE_STATE_T' + nothing shows up as
regards the 'incompatible pointer' ..

tcc has proved the best compiler as regards speed , up to 20* if have mix of gtk + gles.. + the obvious as regards the pointers above.

hope to be back on track soon . still very occupied on the work front. .. but have managed to get to grips with gles , as indicator 0 is bottom ,
most things on Linux 0 is top.. load a picture as a texture and the thing is upside down..

drawing a line or a triangle is easy draw a square or something more complex requires fiddling with the arrays + the method

the basics are these not the api does not have glbegin nor glend, to draw a square need the correct size array then tell it to draw the four bits
within the draw arrays() so tho get a SQUARE one would use the GL_TRIANGLE_FAN :: glDrawArrays(GL_TRIANGLE_FAN, 0, 4)

/* BeginMode
GL_POINTS
GL_LINES
GL_LINE_LOOP
GL_LINE_STRIP
GL_TRIANGLES
GL_TRIANGLE_STRIP
GL_TRIANGLE_FAN
*/

anyway ..

here is the linker and libs options for Bacon using tcc

-O2 -g -lm -ldl -pipe -L. -I/usr/lib/arm-linux-gnueabihf/ -I/opt/vc/include -I/opt/vc/include/interface/vcos/pthreads -I/opt/vc/include/interface/vmcs_host/linux -lGLESv2 -lEGL -lm -lbcm_host -L/opt/vc/lib -lbacon -L /usr/local/lib

BR
Alex

[alexfish]

Hi Peter

not sure of the actual problem ,.. well possible a Bacon parsing one.. re globals and locals + using USEC statements

here the first code is working the second code block produces err message from bacon
Line 218: LOCAL esContext TYPE ESContext

insert quote here

code working so far

'
' Book:      OpenGL(R) ES 2.0 Programming Guide
' Authors:   Aaftab Munshi, Dan Ginsburg, Dave Shreiner
' ISBN-10:   0321502795
' ISBN-13:   9780321502797
' Publisher: Addison-Wesley Professional
' URLs:      http://safari.informit.com/9780321563835
'            http://www.opengles-book.com
'

' Hello_Triangle.c
'
'    This is a simple example that draws a single triangle with
'    a minimal vertex/fragment shader.  The purpose of this
'    example is to demonstrate the basic concepts of
'    OpenGL ES 2.0 rendering.

OPTION PARSE FALSE

PRAGMA INCLUDE esUtil.h
PRAGMA INCLUDE esUtil.c
PRAGMA INCLUDE esTransform.c
PRAGMA INCLUDE esShader.c
PRAGMA INCLUDE esShapes.c

PRAGMA OPTIONS -DRPI_NO_X -I/usr/lib/arm-linux-gnueabihf/ -I/opt/vc/include -I/opt/vc/include/interface/vcos/pthreads -I/opt/vc/include/interface/vmcs_host/linux -lGLESv2 -lEGL -lm -lbcm_host -L/opt/vc/lib -lbacon -L /usr/local/lib -ldl -lm

REM TODO resolve bacon casting struts to pointer
USEC
typedef struct
{
  // Handle to a program object
  GLuint programObject;

} UserData;

END USEC

REM Create a shader object, load the shader source, and
REM compile the shader.



FUNCTION LoadShader ( GLenum type, const char *shaderSrc ) TYPE GLuint

  LOCAL shader TYPE GLuint
  LOCAL compiled TYPE GLint
 
  REM Create the shader object
  shader = glCreateShader ( type )

IF ( shader == 0 ) THEN
RETURN 0
END IF
  REM Load the shader source
  CALL glShaderSource ( shader, 1, &shaderSrc, NULL )
 
  REM Compile the shader
  CALL glCompileShader ( shader )

  REM Check the compile status
  CALL glGetShaderiv ( shader, GL_COMPILE_STATUS, &compiled )

  IF NOT(compiled ) THEN
 
     LOCAL infoLen = 0 TYPE GLint

     CALL glGetShaderiv ( shader, GL_INFO_LOG_LENGTH, &infoLen );
     
     IF ( infoLen > 1 ) THEN
     USEC
        char* infoLog = malloc (sizeof(char) * infoLen );
END USEC
        CALL glGetShaderInfoLog ( shader, infoLen, NULL, infoLog )
        CALL esLogMessage ( "Error compiling shader:\n%s\n", infoLog )          
       
        FREE infoLog
     ENDIF

     CALL glDeleteShader ( shader )

     RETURN 0
  ENDIF

  RETURN shader


ENDFUNCTION



FUNCTION Init ( ESContext *esContext ) TYPE int


USEC
typedef struct
{
  // Handle to a program object
  GLuint programObject;

} UserData;
END USEC
  LET esContext->userData = malloc(sizeof(UserData));


LOCAL *userData TYPE UserData
  userData = esContext->userData

USEC
  GLbyte vShaderStr[] =  
     "attribute vec4 vPosition;    \n"
     "void main()                  \n"
     "{                            \n"
     "   gl_Position = vPosition;  \n"
     "}                            \n";
 
  GLbyte fShaderStr[] =  
     "precision mediump float;\n"\
     "void main()                                  \n"
     "{                                            \n"
     "  gl_FragColor = vec4 ( 1.0, 0.0, 0.0, 1.0 );\n"
     "}                                            \n";
END USEC

  LOCAL vertexShader TYPE GLuint
  LOCAL fragmentShader TYPE GLuint
  LOCAL programObject TYPE GLuint
  LOCAL linked TYPE GLint

  REM Load the vertex/fragment shaders
  vertexShader = LoadShader ( GL_VERTEX_SHADER, vShaderStr )
  fragmentShader = LoadShader ( GL_FRAGMENT_SHADER, fShaderStr )

  REM Create the program object
  programObject = glCreateProgram ( )
 
  IF programObject == 0 THEN
     RETURN 0
  END IF

  glAttachShader ( programObject, vertexShader )
  glAttachShader ( programObject, fragmentShader )

  REM Bind vPosition to attribute 0  
  glBindAttribLocation ( programObject, 0, "vPosition" )

  REM Link the program
  glLinkProgram ( programObject )

  REM Check the link status
  glGetProgramiv ( programObject, GL_LINK_STATUS, &linked )

  IF NOT(linked) THEN
 
     LOCAL infoLen = 0 TYPE GLint

     glGetProgramiv ( programObject, GL_INFO_LOG_LENGTH, &infoLen )
     
     IF infoLen > 1 THEN
      LOCAL infoLog TYPE char*
         infoLog = malloc (sizeof(char) * infoLen );

        glGetProgramInfoLog ( programObject, infoLen, NULL, infoLog );
        esLogMessage ( "Error linking program:\n%s\n", infoLog );            
       
        FREE infoLog
     END IF

     glDeleteProgram ( programObject )
     RETURN GL_FALSE
  END IF

  REM Store the program object
  userData->programObject = programObject;

  glClearColor ( 0.0f, 0.0f, 0.0f, 1.0f );

  RETURN GL_TRUE
END FUNCTION

USEC

// Draw a triangle using the shader pair created in Init()
//
void Draw ( ESContext *esContext )
{
  UserData *userData = esContext->userData;
  GLfloat vVertices[] = {  0.0f,  0.5f, 0.0f,
                          -0.5f, -0.5f, 0.0f,
                           0.5f, -0.5f, 0.0f };
     
  // Set the viewport
  glViewport ( 0, 0, esContext->width, esContext->height );
 
  // Clear the color buffer
  glClear ( GL_COLOR_BUFFER_BIT );

  // Use the program object
  glUseProgram ( userData->programObject );

  // Load the vertex data
  glVertexAttribPointer ( 0, 3, GL_FLOAT, GL_FALSE, 0, vVertices );
  glEnableVertexAttribArray ( 0 );

  glDrawArrays ( GL_TRIANGLES, 0, 3 );
}

ENDUSEC

LOCAL esContext TYPE ESContext
LOCAL userData TYPE UserData

   esInitContext ( &esContext )
  esContext.userData = &userData

  esCreateWindow ( &esContext, "Hello Triangle", 320, 240, ES_WINDOW_RGB )

  Init( &esContext )


  esRegisterDrawFunc ( &esContext, Draw )

  esMainLoop ( &esContext )

Now the here, at that last conversion of the sub before main
'
' Book:      OpenGL(R) ES 2.0 Programming Guide
' Authors:   Aaftab Munshi, Dan Ginsburg, Dave Shreiner
' ISBN-10:   0321502795
' ISBN-13:   9780321502797
' Publisher: Addison-Wesley Professional
' URLs:      http://safari.informit.com/9780321563835
'            http://www.opengles-book.com
'

' Hello_Triangle.c
'
'    This is a simple example that draws a single triangle with
'    a minimal vertex/fragment shader.  The purpose of this
'    example is to demonstrate the basic concepts of
'    OpenGL ES 2.0 rendering.

OPTION PARSE FALSE

PRAGMA INCLUDE esUtil.h
PRAGMA INCLUDE esUtil.c
PRAGMA INCLUDE esTransform.c
PRAGMA INCLUDE esShader.c
PRAGMA INCLUDE esShapes.c

PRAGMA OPTIONS -DRPI_NO_X -I/usr/lib/arm-linux-gnueabihf/ -I/opt/vc/include -I/opt/vc/include/interface/vcos/pthreads -I/opt/vc/include/interface/vmcs_host/linux -lGLESv2 -lEGL -lm -lbcm_host -L/opt/vc/lib -lbacon -L /usr/local/lib -ldl -lm

REM TODO resolve bacon casting struts to pointer
USEC
typedef struct
{
  // Handle to a program object
  GLuint programObject;

} UserData;

END USEC

REM Create a shader object, load the shader source, and
REM compile the shader.



FUNCTION LoadShader ( GLenum type, const char *shaderSrc ) TYPE GLuint

  LOCAL shader TYPE GLuint
  LOCAL compiled TYPE GLint
 
  REM Create the shader object
  shader = glCreateShader ( type )

IF ( shader == 0 ) THEN
RETURN 0
END IF
  REM Load the shader source
  CALL glShaderSource ( shader, 1, &shaderSrc, NULL )
 
  REM Compile the shader
  CALL glCompileShader ( shader )

  REM Check the compile status
  CALL glGetShaderiv ( shader, GL_COMPILE_STATUS, &compiled )

  IF NOT(compiled ) THEN
 
     LOCAL infoLen = 0 TYPE GLint

     CALL glGetShaderiv ( shader, GL_INFO_LOG_LENGTH, &infoLen );
     
     IF ( infoLen > 1 ) THEN
     USEC
        char* infoLog = malloc (sizeof(char) * infoLen );
END USEC
        CALL glGetShaderInfoLog ( shader, infoLen, NULL, infoLog )
        CALL esLogMessage ( "Error compiling shader:\n%s\n", infoLog )          
       
        FREE infoLog
     ENDIF

     CALL glDeleteShader ( shader )

     RETURN 0
  ENDIF

  RETURN shader


ENDFUNCTION



FUNCTION Init ( ESContext *esContext ) TYPE int


USEC
typedef struct
{
  // Handle to a program object
  GLuint programObject;

} UserData;
END USEC
  LET esContext->userData = malloc(sizeof(UserData));


LOCAL *userData TYPE UserData
  userData = esContext->userData

USEC
  GLbyte vShaderStr[] =  
     "attribute vec4 vPosition;    \n"
     "void main()                  \n"
     "{                            \n"
     "   gl_Position = vPosition;  \n"
     "}                            \n";
 
  GLbyte fShaderStr[] =  
     "precision mediump float;\n"\
     "void main()                                  \n"
     "{                                            \n"
     "  gl_FragColor = vec4 ( 1.0, 0.0, 0.0, 1.0 );\n"
     "}                                            \n";
END USEC

  LOCAL vertexShader TYPE GLuint
  LOCAL fragmentShader TYPE GLuint
  LOCAL programObject TYPE GLuint
  LOCAL linked TYPE GLint

  REM Load the vertex/fragment shaders
  vertexShader = LoadShader ( GL_VERTEX_SHADER, vShaderStr )
  fragmentShader = LoadShader ( GL_FRAGMENT_SHADER, fShaderStr )

  REM Create the program object
  programObject = glCreateProgram ( )
 
  IF programObject == 0 THEN
     RETURN 0
  END IF

  glAttachShader ( programObject, vertexShader )
  glAttachShader ( programObject, fragmentShader )

  REM Bind vPosition to attribute 0  
  glBindAttribLocation ( programObject, 0, "vPosition" )

  REM Link the program
  glLinkProgram ( programObject )

  REM Check the link status
  glGetProgramiv ( programObject, GL_LINK_STATUS, &linked )

  IF NOT(linked) THEN
 
     LOCAL infoLen = 0 TYPE GLint

     glGetProgramiv ( programObject, GL_INFO_LOG_LENGTH, &infoLen )
     
     IF infoLen > 1 THEN
      LOCAL infoLog TYPE char*
         infoLog = malloc (sizeof(char) * infoLen );

        glGetProgramInfoLog ( programObject, infoLen, NULL, infoLog );
        esLogMessage ( "Error linking program:\n%s\n", infoLog );            
       
        FREE infoLog
     END IF

     glDeleteProgram ( programObject )
     RETURN GL_FALSE
  END IF

  REM Store the program object
  userData->programObject = programObject;

  glClearColor ( 0.0f, 0.0f, 0.0f, 1.0f );

  RETURN GL_TRUE
END FUNCTION

USEC

REM Draw a triangle using the shader pair created in Init()

SUB Draw ( ESContext *esContext )

USEC
typedef struct
{
  // Handle to a program object
  GLuint programObject;

} UserData;
END USEC

  UserData *userData = esContext->userData;
  GLfloat vVertices[] = {  0.0f,  0.5f, 0.0f,  -0.5f, -0.5f, 0.0f,0.5f, -0.5f, 0.0f };
     
  REM Set the viewport
  glViewport ( 0, 0, esContext->width, esContext->height )
 
  REM Clear the color buffer
  glClear ( GL_COLOR_BUFFER_BIT )

  REM Use the program object
  glUseProgram ( userData->programObject )

  REM Load the vertex data
  glVertexAttribPointer ( 0, 3, GL_FLOAT, GL_FALSE, 0, vVertices )
  glEnableVertexAttribArray ( 0 );

  glDrawArrays ( GL_TRIANGLES, 0, 3 )

END SUB



LOCAL esContext TYPE ESContext
LOCAL userData TYPE UserData

  esInitContext ( &esContext )
  esContext.userData = &userData

  esCreateWindow ( &esContext, "Hello Triangle", 320, 240, ES_WINDOW_RGB )

  Init( &esContext )


  esRegisterDrawFunc ( &esContext, Draw )

  esMainLoop ( &esContext )

Also Note that the Code requires the ' UserData' struct within each sub ;;

other than that .. almost there with EGL and GLES

BR
Alex

[alexfish]

Hi Peter

Scratch the above .. Had a Stray USEC in the code

This works ,, So now looking at a Global type def struct ;; IE where having to cast the struct to pointer in every sub or function

also not that the code still has some CALL syntax this will not be required when using statement

OPTION PARSE FALSE

BR
Alex

The code working so far ;; Pity can not post a picture since screen shot can not pick up on frame buffer or the EGL
'
' Book:      OpenGL(R) ES 2.0 Programming Guide
' Authors:   Aaftab Munshi, Dan Ginsburg, Dave Shreiner
' ISBN-10:   0321502795
' ISBN-13:   9780321502797
' Publisher: Addison-Wesley Professional
' URLs:      http://safari.informit.com/9780321563835
'            http://www.opengles-book.com
'

' Hello_Triangle.c
'
'    This is a simple example that draws a single triangle with
'    a minimal vertex/fragment shader.  The purpose of this
'    example is to demonstrate the basic concepts of
'    OpenGL ES 2.0 rendering.

OPTION PARSE FALSE

PRAGMA INCLUDE esUtil.h
PRAGMA INCLUDE esUtil.c
PRAGMA INCLUDE esTransform.c
PRAGMA INCLUDE esShader.c
PRAGMA INCLUDE esShapes.c

PRAGMA OPTIONS -DRPI_NO_X -I/usr/lib/arm-linux-gnueabihf/ -I/opt/vc/include -I/opt/vc/include/interface/vcos/pthreads -I/opt/vc/include/interface/vmcs_host/linux -lGLESv2 -lEGL -lm -lbcm_host -L/opt/vc/lib -lbacon -L /usr/local/lib -ldl -lm

REM TODO resolve bacon casting struts to pointer
USEC
typedef struct
{
  // Handle to a program object
  GLuint programObject;

} UserData;

END USEC

REM Create a shader object, load the shader source, and
REM compile the shader.



FUNCTION LoadShader ( GLenum type, const char *shaderSrc ) TYPE GLuint

  LOCAL shader TYPE GLuint
  LOCAL compiled TYPE GLint
 
  REM Create the shader object
  shader = glCreateShader ( type )

IF ( shader == 0 ) THEN
RETURN 0
END IF
  REM Load the shader source
  CALL glShaderSource ( shader, 1, &shaderSrc, NULL )
 
  REM Compile the shader
  CALL glCompileShader ( shader )

  REM Check the compile status
  CALL glGetShaderiv ( shader, GL_COMPILE_STATUS, &compiled )

  IF NOT(compiled ) THEN
 
     LOCAL infoLen = 0 TYPE GLint

     CALL glGetShaderiv ( shader, GL_INFO_LOG_LENGTH, &infoLen );
     
     IF ( infoLen > 1 ) THEN
     USEC
        char* infoLog = malloc (sizeof(char) * infoLen );
END USEC
        CALL glGetShaderInfoLog ( shader, infoLen, NULL, infoLog )
        CALL esLogMessage ( "Error compiling shader:\n%s\n", infoLog )          
       
        FREE infoLog
     ENDIF

     CALL glDeleteShader ( shader )

     RETURN 0
  ENDIF

  RETURN shader


ENDFUNCTION



FUNCTION Init ( ESContext *esContext ) TYPE int


USEC
typedef struct
{
  // Handle to a program object
  GLuint programObject;

} UserData;
END USEC
  LET esContext->userData = malloc(sizeof(UserData));


LOCAL *userData TYPE UserData
  userData = esContext->userData

USEC
  GLbyte vShaderStr[] =  
     "attribute vec4 vPosition;    \n"
     "void main()                  \n"
     "{                            \n"
     "   gl_Position = vPosition;  \n"
     "}                            \n";
 
  GLbyte fShaderStr[] =  
     "precision mediump float;\n"\
     "void main()                                  \n"
     "{                                            \n"
     "  gl_FragColor = vec4 ( 1.0, 0.0, 0.0, 1.0 );\n"
     "}                                            \n";
END USEC

  LOCAL vertexShader TYPE GLuint
  LOCAL fragmentShader TYPE GLuint
  LOCAL programObject TYPE GLuint
  LOCAL linked TYPE GLint

  REM Load the vertex/fragment shaders
  vertexShader = LoadShader ( GL_VERTEX_SHADER, vShaderStr )
  fragmentShader = LoadShader ( GL_FRAGMENT_SHADER, fShaderStr )

  REM Create the program object
  programObject = glCreateProgram ( )
 
  IF programObject == 0 THEN
     RETURN 0
  END IF

  glAttachShader ( programObject, vertexShader )
  glAttachShader ( programObject, fragmentShader )

  REM Bind vPosition to attribute 0  
  glBindAttribLocation ( programObject, 0, "vPosition" )

  REM Link the program
  glLinkProgram ( programObject )

  REM Check the link status
  glGetProgramiv ( programObject, GL_LINK_STATUS, &linked )

  IF NOT(linked) THEN
 
     LOCAL infoLen = 0 TYPE GLint

     glGetProgramiv ( programObject, GL_INFO_LOG_LENGTH, &infoLen )
     
     IF infoLen > 1 THEN
      LOCAL infoLog TYPE char*
         infoLog = malloc (sizeof(char) * infoLen );

        glGetProgramInfoLog ( programObject, infoLen, NULL, infoLog );
        esLogMessage ( "Error linking program:\n%s\n", infoLog );            
       
        FREE infoLog
     END IF

     glDeleteProgram ( programObject )
     RETURN GL_FALSE
  END IF

  REM Store the program object
  userData->programObject = programObject;

  glClearColor ( 0.0f, 0.0f, 0.0f, 1.0f );

  RETURN GL_TRUE
END FUNCTION



REM Draw a triangle using the shader pair created in Init()

SUB Draw ( ESContext *esContext )

USEC
typedef struct
{
  // Handle to a program object
  GLuint programObject;

} UserData;
END USEC
LOCAL  *userData TYPE UserData
   userData = esContext->userData;
  GLfloat vVertices[] = {  0.0f,  0.5f, 0.0f,  -0.5f, -0.5f, 0.0f,0.5f, -0.5f, 0.0f };
     
  REM Set the viewport
  glViewport ( 0, 0, esContext->width, esContext->height )
 
  REM Clear the color buffer
  glClear ( GL_COLOR_BUFFER_BIT )

  REM Use the program object
  glUseProgram ( userData->programObject )

  REM Load the vertex data
  glVertexAttribPointer ( 0, 3, GL_FLOAT, GL_FALSE, 0, vVertices )
  glEnableVertexAttribArray ( 0 );

  glDrawArrays ( GL_TRIANGLES, 0, 3 )

END SUB



LOCAL esContext TYPE ESContext
LOCAL userData TYPE UserData

  esInitContext ( &esContext )
  esContext.userData = &userData

  esCreateWindow ( &esContext, "Hello Triangle", 320, 240, ES_WINDOW_RGB )

  Init( &esContext )


  esRegisterDrawFunc ( &esContext, Draw )

  esMainLoop ( &esContext )

Edit :: forgot to mention, U need to paste the line of code shown below in the BaCon GUI "Library" box upon compile , it is the same as in the PRAGMA OPTIONS
-DRPI_NO_X -I/usr/lib/arm-linux-gnueabihf/ -I/opt/vc/include -I/opt/vc/include/interface/vcos/pthreads -I/opt/vc/include/interface/vmcs_host/linux -lGLESv2 -lEGL -lm -lbcm_host -L/opt/vc/lib -lbacon -L /usr/local/lib -ldl -lm

[alexfish]

Hi All

as a reminder , the Book Examples also includes code examples for the Following devices/OS & or Desktop

Android
BlackBerry
iPhone
LinuxX11
WebGL
Windows

BR
Alex

[alexfish]

GL colours

Gles colors values are 0.0f to 1.0f

as an aproximation ,if want to convert decimal rgb to GLfloat value one can look at these

GLfloat R = (r/7.96875)/32 : GLfloat G = (g/7.96875)/32 : GLfloat B = (b/7.96875)/32
Where r,g,b values are 0 to 255

GLfloat R = (0/7.96875)/32 : GLfloat G = (0/7.96875)/32 : GLfloat B = (0/7.96875)/32 = Black

GLfloat R = (255/7.96875)/32 : GLfloat G = (255/7.96875)/32 : GLfloat B = (255/7.96875)/32 = White

can then use the BaCon Colour Chooser to get the decimal rgb values

suppose can use the same algo for the alpha

BR
Alex

[alexfish]

just a couple of recommends , before I be starting a bacon lib for using the open-gl es egles.

here are what can be done to ensure compat with c and c++ OR other compilers . but def for gcc & g++ and tcc

if c++ add these to the program header

extern "C" {
extern void bcm_host_init();
extern void bcm_host_deinit();
extern int graphics_get_display_size(int,void*,void*);
}


then for all

omit the include #include "bcm_host.h"

In The Book Examples :: Common

in the esUtil.c at lines 171 to 173


dispman_element = vc_dispmanx_element_add ( dispman_update, dispman_display,
     0/*layer*/, &dst_rect, 0/*src*/,
     &src_rect, DISPMANX_PROTECTION_NONE, 0 /*alpha*/, 0/*clamp*/, 0/*transform*/);

change to

// added (DISPMANX_TRANSFORM_T)
  dispman_element = vc_dispmanx_element_add ( dispman_update, dispman_display,
     0/*layer*/, &dst_rect, 0/*src*/,
     &src_rect, DISPMANX_PROTECTION_NONE, 0 /*alpha*/, 0/*clamp*/,(DISPMANX_TRANSFORM_T) 0/*transform*/);


compiler flags

these should work

-I/opt/vc/include -I/opt/vc/include/interface/vcos/pthreads -I/opt/vc/include/interface/vmcs_host/linux  -lGLESv2 -lEGL -lm -lbcm_host -lvcos -lvchiq_arm -lpthread -lrt -L/opt/vc/lib -lm

also can test the vc demos triangle one and two . need a change here

the line that is required is in CreateEGLContext

change these line 107

context = eglCreateContext(display, config, EGL_NO_CONTEXT, contextAttribs );

to
 // Create a GL context
// TODO testing by swapping
//  context = eglCreateContext(display, config, EGL_NO_CONTEXT, contextAttribs );
context = eglCreateContext(display, config, EGL_NO_CONTEXT, NULL );

Edit Added :: missed a one , actually an important bit for the Rasby
also think this could be a bug , in least all the Flashy flickers disapear

in sub routine ' CreateEGLContext
lines 67 to 79 , note that looks like egl x server display when a request is for a egl display period 'RPI_NO_X ' means no X and get

'display = eglGetDisplay((EGLNativeDisplayType)x_display);

 //CreateEGLContext
  // Get Display
  #ifndef RPI_NO_X
  display = eglGetDisplay((EGLNativeDisplayType)x_display);
  if ( display == EGL_NO_DISPLAY )
  {
     return EGL_FALSE;
  }
  #else
  display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
  if ( display == EGL_NO_DISPLAY )
  {
     return EGL_FALSE;
  }
#endif

replace all with

// Get Display EGL_DEFAULT_DISPLAY
//TODO
// display = eglGetDisplay((EGLNativeDisplayType)x_display);
display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
  if ( display == EGL_NO_DISPLAY )
  {
     return EGL_FALSE;
  }
with all changes , there should be no conflict of egl apps + can make multiple context/surfaces , have not fully tested , yet but they should come out as layers
make the surface context , the clear and swap the buffers using
the alpha 0.0

for each layer above the base layer test first with
glClearColor(1.0f, 1.0f, 1.0f, 0.5f);
then
glClearColor(1.0f, 1.0f, 1.0f, 0.0f);


also change the init stages 'esCreateWindow' of the esUtil.c

full code here

// TODO
// THE ENTRY POINT
int  esCreateWindow ( ESContext *esContext, GLint width, GLint height, GLuint flags ){

  EGLint attribList[] =
  {

     EGL_RED_SIZE, 8,
     EGL_GREEN_SIZE, 8,
     EGL_BLUE_SIZE, 8,
     EGL_ALPHA_SIZE, 8,
     EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
     EGL_NONE

     // EGL_RED_SIZE,       5,
     // EGL_GREEN_SIZE,     6,
     // EGL_BLUE_SIZE,      5,
     // EGL_ALPHA_SIZE,      8,
     // EGL_DEPTH_SIZE,     8 ,
     // EGL_STENCIL_SIZE,    8,
     // EGL_SAMPLE_BUFFERS, 8
     // EGL_NONE
  };
 
  if ( esContext == NULL )
  {
     return GL_FALSE;
  }

  esContext->width = width;
  esContext->height = height;

  if ( !WinCreate ( esContext) )
  {
     return GL_FALSE;
  }

 
  if ( !CreateEGLContext ( esContext->hWnd, &esContext->eglDisplay,&esContext->eglContext,&esContext->eglSurface,attribList) )
  {
     return GL_FALSE;
  }
 

  return GL_TRUE;
}
BR
Alex