[Job] Junior and Senior Developer

My company Global CyberSoft (http://www.globalcybersoft.com) is looking for lot of both Junior and Senior developers which have knowledge of Java or C/C++ & Linux. Experience in Graphics and one of following technique OpenGL, DirectX, Clutter, Webkit, Flash, Driver Development. Wishlist: Experience in Consumer Electronics, with Set Top Box experience being a plus Employment history: Graphics/UI Game Development, Apple, etc Contact hieult@globalcybersoft.com for more information.

How to build Valgrind for Beagleboard

1) Get Valgrind source code from SVN using revision 9648 and 1888 for VEX

svn co -r 9648 svn://svn.valgrind.org/valgrind/trunk

cd VEX

svn update -r 1888

2) Download the patch here http://bugsfiles.kde.org/attachment.cgi?id=32348

3) Apply the patch into the source code

cd valgrind

patch -p1 < [path to the patch]

4) Run autogen.sh to run autotools

5) Configure the source code

./configure --host=arm-angstrom-linux-gnueabi

The patch still has some bugs such as CPU instruction alignment you can 'cat /proc/cpu/alignment' to find out if the kernel is configured to fix unaligned accesses, and you can enable it by executing 'echo 2 > /proc/cpu/alignment' but it's enough to use for simple application.

Have fun with Valgrind :-)

How to build Clutter for Beagleboard

The Clutter need to be configured with =flavour=eglnative= so that it can work with SGX driver
The following is the configure command

./configure --with-flavour=eglnative --host=arm-angstrom-linux-gnueabi PKG_CONFIG=/data/workspace/OE/tmp/staging/i686-linux/usr/bin/pkg-config PKG_CONFIG_PATH=/data/workspace/OE/tmp/staging/armv7a-angstrom-linux-gnueabi/usr/lib/pkgconfig CFLAGS="--sysroot=/data/workspace/OE/tmp/staging/armv7a-angstrom-linux-gnueabi/ -I/data/workspace/OE/tmp/staging/armv7a-angstrom-linux-gnueabi/usr/include" --with-x=no --with-gles=1.1 --with-imagebackend=internal

with

• --host: set the target for the build, need to be arm-angstrom-linux-gnueabi
• PKG_CONFIG: use the pgk-config command from OE distribution
• PKG_CONFIG_PATH: the path to search for *.pc file, need to be pointed to OE distribution
• --with-x: not using X
• --with-imagebackend: specific the image backend to use
• --with-gles: specific the GLES version to use (1.1 or 2.0)
• CFLAGS: override some C compiler flags
• --sysroot: the root directory to search for library and header files
• -I[include_dir]: some optional include directories to search for

Fix undefined rpl_malloc on autoconf tool in cross compile mode

When using autoconf tool in cross compile environment, sometime there is error like this `undefined reference to `rpl_malloc'`

It is the bug of autoconf tool in the test function AC_FUNC_MALLOC. To fix it we need define an environment variable that forces the test to pass. Define it in the environment prior to calling ./configure and the script will act as if the AC_FUNC_MALLOC check has passed.

export ac_cv_func_malloc_0_nonnull=yes

Draw Text with OpenGL and Cairo

The OpenGL just supports capability to draw primitive, not text. In order to draw text on screen we need support of other package such as Cairo or Pango. The following topic describe how to use Cairo with OpenGL.
1 First we need to create a Cairo surface for drawing (text)
2 Then we will load the surface into GL texture using glTextureXXX function
3 After all, we will apply texture mapping into our primitive (for example a rectangle for displaying text)


Create Cairo Context
inline cairo_t*
create_cairo_context (int width,
int height,
int channels,
cairo_surface_t** surf,
unsigned char** buffer)
{
cairo_t* cr;

/* create cairo-surface/context to act as OpenGL-texture source */
*buffer = (unsigned char*)calloc (channels * width * height, sizeof (unsigned char));
if (!*buffer)
{
printf ("create_cairo_context() - Couldn't allocate surface-buffer\n");
return NULL;
}

*surf = cairo_image_surface_create_for_data (*buffer,
CAIRO_FORMAT_ARGB32,
width,
height,
channels * width);
if (cairo_surface_status (*surf) != CAIRO_STATUS_SUCCESS)
{
free (*buffer);
printf ("create_cairo_context() - Couldn't create surface\n");
return NULL;
}

cr = cairo_create (*surf);
if (cairo_status (cr) != CAIRO_STATUS_SUCCESS)
{
free (*buffer);
printf ("create_cairo_context() - Couldn't create context\n");
return NULL;
}

return cr;
}

Draw text into the Cairo surface and then load it into GL Texture
inline int DrawText(int x, int y, int width, int height, char *string, COLOR &textColor, COLOR &background)
{
cairo_surface_t* surface = NULL;
cairo_t* cr;
unsigned char* surfData;
GLuint textureId;

/* create cairo-surface/context to act as OpenGL-texture source */
cr = create_cairo_context (256,
256,
4,
&surface,
&surfData);

/* clear background */
cairo_set_operator(cr, CAIRO_OPERATOR_OVER);
cairo_set_source_rgb(cr, background.red, background.green, background.blue);
cairo_paint (cr);

cairo_move_to(cr, 256/10, 256/2);
cairo_set_font_size(cr, 30);
cairo_select_font_face(cr, "sans", CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
cairo_set_source_rgb(cr, textColor.red, textColor.green, textColor.blue);
cairo_show_text(cr, string);

glGenTextures(1, &textureId);
glBindTexture(GL_TEXTURE_2D, textureId);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D,
0,
GL_RGBA,
256,
256,
0,
GL_RGBA,
GL_UNSIGNED_BYTE,
surfData);
TestEGLError("glTexImage2D");

free (surfData);
cairo_destroy (cr);

return textureId;

}

Texture Mapping
The texture mapping is so simple, we need to provide them the UV coordinate. The UV coordinate is range from 0 to 1 which 0 is the start point, and 1 is the end point. The following is an example usage


GLfloat textureCoord[] = {
f2vt(0.0f), f2vt(0.35f),
f2vt(1.0f), f2vt(0.35f),
f2vt(0.0f), f2vt(0.55f),
f2vt(1.0f), f2vt(0.55f)
};
COLOR clrText = {255,255,255};
glEnable(GL_TEXTURE_2D);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
GLuint textureId = DrawText(clipRect[0], clipRect[1], clipRect[2], clipRect[3], data, clrText, this->m_clrBackground);

glVertexPointer(2, VERTTYPEENUM, 0, rect);
glTexCoordPointer(2, VERTTYPEENUM, 0, textureCoord);

glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);

glDeleteTextures(1, &textureId);

Enable 2D Over OpenGL

In OpenGL, if we want to 2D only, we can use the Ortho matrix to set ignore the z-list. The following code snippet demo how to do that

void glEnable2D()
{
int vPort[4];

glGetIntegerv(GL_VIEWPORT, vPort);

glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();

glOrtho(0, vPort[2], 0, vPort[3], -1, 1);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
}

void glDisable2D()
{
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
}

Boot beagleboard with S-Video output

Boot beagleboard with S-Video output

setenv bootargs console=ttyS2,115200n8 root=/dev/mmcblk0p2 rw rootfstype=ext3 rootwait omapfb.mode=tv:1024x768-16@60 omapdss.def_disp=tv
mmcinit
fatload mmc 0:1 0x80300000
uImage-2.6.29 bootm 0x80300000