cgraphics3dfedoracogl

How to compile Cogl hello example


My environment is Fedora 21, i play around with hello tutorial from http://www.cogl3d.org/hello.html, it shows:

Building the example

If you save the above code to a file named hello.c then you can compile the example as follows:

gcc -o hello hello.c pkg-config --cflags --libs cogl2 glib-2.0

but where can i find cogl2 library ?

If i doesn't include cogl library:

[xiaobai@xiaobai cogl]$ gcc -o hello hello.c `pkg-config --cflags --libs glib-2.0` 
hello.c:1:23: fatal error: cogl/cogl.h: No such file or directory
 #include <cogl/cogl.h>
                       ^
compilation terminated.
[xiaobai@xiaobai cogl]$ 

i tried dnf search cogl but there's only cogl, no such thing cogl2:

[xiaobai@xiaobai cogl]$ dnf search cogl
[sudo] password for xiaobai: 
================================================================= N/S Matched: cogl ==================================================================
cogl.x86_64 : A library for using 3D graphics hardware to draw pretty pictures
cogl.i686 : A library for using 3D graphics hardware to draw pretty pictures
cogl-doc.noarch : Documentation for cogl
cogl-devel.x86_64 : cogl development environment
cogl-devel.i686 : cogl development environment
[xiaobai@xiaobai cogl]$ 

I also search for cogl.h, no such cogl2 too:

[xiaobai@xiaobai yum]$ dnf provides */cogl.h
cogl-devel-1.18.2-9.fc21.x86_64 : cogl development environment
Repo        : @System

cogl-devel-1.18.2-9.fc21.i686 : cogl development environment
Repo        : fedora

cogl-devel-1.18.2-9.fc21.x86_64 : cogl development environment
Repo        : fedora

[xiaobai@xiaobai yum]$ 

I can't use pkg-config to find neither cogl nor cogl2:

[xiaobai@xiaobai cogl]$ pkg-config --cflags --libs cogl2 cogl
Package cogl2 was not found in the pkg-config search path.
Perhaps you should add the directory containing `cogl2.pc'
to the PKG_CONFIG_PATH environment variable
No package 'cogl2' found
Package cogl was not found in the pkg-config search path.
Perhaps you should add the directory containing `cogl.pc'
to the PKG_CONFIG_PATH environment variable
No package 'cogl' found
[xiaobai@xiaobai cogl]$ 

So i simply tried cogl:

$ gcc -o hello hello.c pkg-config --cflags --libs glib-2.0 -I/usr/include/cogl/

, it shows a lot of error messages:

[xiaobai@xiaobai cogl]$ gcc -o hello hello.c `pkg-config --cflags --libs glib-2.0` -I/usr/include/cogl/ 
hello.c:45:17: error: unknown type name ‘CoglOnscreen’
 frame_event_cb (CoglOnscreen *onscreen,
                 ^
hello.c:46:17: error: unknown type name ‘CoglFrameEvent’
                 CoglFrameEvent event,
                 ^
hello.c:47:17: error: unknown type name ‘CoglFrameInfo’
                 CoglFrameInfo *info,
                 ^
hello.c:59:11: error: unknown type name ‘CoglOnscreen’
 dirty_cb (CoglOnscreen *onscreen,
           ^
hello.c:60:17: error: unknown type name ‘CoglOnscreenDirtyInfo’
           const CoglOnscreenDirtyInfo *info,
                 ^
hello.c: In function ‘main’:
hello.c:86:14: warning: assignment makes pointer from integer without a cast
     data.ctx = cogl_context_new (NULL, &error);
              ^
hello.c:92:13: warning: assignment makes pointer from integer without a cast
     data.fb = cogl_onscreen_new (data.ctx, 640, 480);
             ^
hello.c:98:19: warning: assignment makes pointer from integer without a cast
     data.pipeline = cogl_pipeline_new (data.ctx);
                   ^
hello.c:100:17: warning: assignment makes pointer from integer without a cast
     cogl_source = cogl_glib_source_new (data.ctx, G_PRIORITY_DEFAULT);
                 ^
hello.c:105:39: error: ‘frame_event_cb’ undeclared (first use in this function)
                                       frame_event_cb,
                                       ^
hello.c:105:39: note: each undeclared identifier is reported only once for each function it appears in
hello.c:110:39: error: ‘dirty_cb’ undeclared (first use in this function)
                                       dirty_cb,
                                       ^
[xiaobai@xiaobai cogl]$ 

Any help is much appreciate.

[UPDATE] i've tried @CYB3R solution but still no luck:

[xiaobai@xiaobai cogl]$ pkg-config --cflags --libs cogl-2.0-experimental glib-2.0 
-pthread -I/usr/include/cogl -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libpng16 -I/usr/include/libdrm -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -lcogl -lgmodule-2.0 -pthread -lgdk_pixbuf-2.0 -lgobject-2.0 -lwayland-egl -lwayland-client -lgbm -ldrm -lwayland-server -lEGL -lX11 -lXext -lXdamage -lXfixes -lXcomposite -lXrandr -lglib-2.0 
[xiaobai@xiaobai cogl]$ gcc -pthread -I/usr/include/cogl -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libpng16 -I/usr/include/libdrm -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -lcogl -lgmodule-2.0 -pthread -lgdk_pixbuf-2.0 -lgobject-2.0 -lwayland-egl -lwayland-client -lgbm -ldrm -lwayland-server -lEGL -lX11 -lXext -lXdamage -lXfixes -lXcomposite -lXrandr -lglib-2.0 hello.c 
hello.c:45:17: error: unknown type name ‘CoglOnscreen’
 frame_event_cb (CoglOnscreen *onscreen,
                 ^
hello.c:46:17: error: unknown type name ‘CoglFrameEvent’
                 CoglFrameEvent event,
                 ^
... #same errors like previous
[xiaobai@xiaobai cogl]$ 

Solution

  • First step, recognize it missing type name CoglOnscreen:

    [xiaobai@xiaobai cogl]$ gcc -pthread -I/usr/include/cogl -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libpng16 -I/usr/include/libdrm -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -lcogl -lgmodule-2.0 -pthread -lgdk_pixbuf-2.0 -lgobject-2.0 -lwayland-egl -lwayland-client -lgbm -ldrm -lwayland-server -lEGL -lX11 -lXext -lXdamage -lXfixes -lXcomposite -lXrandr -lglib-2.0 hello.c 
    hello.c:45:17: error: unknown type name ‘CoglOnscreen’
     frame_event_cb (CoglOnscreen *onscreen,
                     ^
    hello.c:46:17: error: unknown type name ‘CoglFrameEvent’
                     CoglFrameEvent event,
                     ^
    

    Now i know CoglOnscreen supposed to be located somewhere, so i tried search "CoglOnscreen" keyword inside include dir:

    [xiaobai@xiaobai cogl]$ grep -rnI CoglOnscreen /usr/include/cogl/cogl/*  
    /usr/include/cogl/cogl/cogl-context.h:250: * @COGL_FEATURE_ID_BUFFER_AGE: Available if the age of #CoglOnscreen back
    /usr/include/cogl/cogl/cogl-display.h:91: * @onscreen_template: A #CoglOnscreenTemplate
    /usr/include/cogl/cogl/cogl-display.h:130:                  CoglOnscreenTemplate *onscreen_template);
    /usr/include/cogl/cogl/cogl-display.h:149: * @onscreen_template: A template for creating #CoglOnscreen framebuffers
    /usr/include/cogl/cogl/cogl-display.h:151: * Specifies a template for creating #CoglOnscreen framebuffers.
    /usr/include/cogl/cogl/cogl-display.h:153: * Depending on the system, the constraints for creating #CoglOnscreen
    /usr/include/cogl/cogl/cogl-display.h:164:                                    CoglOnscreenTemplate *onscreen_template);
    /usr/include/cogl/cogl/cogl-framebuffer.h:79: * There are two kinds of framebuffer in Cogl, #CoglOnscreen
    /usr/include/cogl/cogl/cogl-framebuffer.h:85: * rendering to a #CoglOnscreen framebuffer will be immediately
    /usr/include/cogl/cogl/cogl-framebuffer.h:89: * looking at the #CoglOnscreen and #CoglOffscreen constructor
    /usr/include/cogl/cogl/cogl-framebuffer.h:1657: * already implicitly discard when you finish rendering to a #CoglOnscreen
    /usr/include/cogl/cogl/cogl-frame-info.h:80: * Gets the frame counter for the #CoglOnscreen that corresponds
    /usr/include/cogl/cogl/cogl-gles2.h:198: * #CoglOffscreen framebuffers (Rendering to #CoglOnscreen
    /usr/include/cogl/cogl/cogl-kms-display.h:48: * #CoglOnscreen swap_buffers request. For applications that support
    /usr/include/cogl/cogl/cogl-onscreen.h:52:typedef struct _CoglOnscreen CoglOnscreen;
    ...
    

    The last line above shown that "cogl-onscreen.h" have CoglOnscreen defined. So i search for cogl-onscreen.h:

    [xiaobai@xiaobai cogl]$ grep -rnI 'cogl-onscreen.h' /usr/include/cogl/cogl/*
    /usr/include/cogl/cogl/cogl.h:133:#include <cogl/cogl-onscreen.h>
    [xiaobai@xiaobai cogl]$ 
    

    vi /usr/include/cogl/cogl/cogl.h and search for "cogl-onscreen.h" keyword:

    ...
    /*
     * 2.0 api that's compatible with the 1.x api...
     */
    #if defined (COGL_ENABLE_EXPERIMENTAL_API)
    #include <cogl/cogl-swap-chain.h>
    #include <cogl/cogl-renderer.h>
    #include <cogl/cogl-output.h>
    #include <cogl/cogl-display.h>
    #include <cogl/cogl-context.h>
    #include <cogl/cogl-buffer.h>
    #include <cogl/cogl-pixel-buffer.h>
    #include <cogl/cogl-vector.h>
    #include <cogl/cogl-euler.h>
    #include <cogl/cogl-quaternion.h>
    #include <cogl/cogl-texture-2d.h>
    #include <cogl/cogl-texture-2d-gl.h>
    #include <cogl/cogl-texture-rectangle.h>
    #include <cogl/cogl-texture-3d.h>
    #include <cogl/cogl-texture-2d-sliced.h>
    #include <cogl/cogl-sub-texture.h>
    #include <cogl/cogl-atlas-texture.h>
    #include <cogl/cogl-meta-texture.h>
    #include <cogl/cogl-primitive-texture.h>
    #include <cogl/cogl-index-buffer.h>
    #include <cogl/cogl-attribute-buffer.h>
    #include <cogl/cogl-indices.h>
    #include <cogl/cogl-attribute.h>
    #include <cogl/cogl-primitive.h>
    #include <cogl/cogl-depth-state.h>
    #include <cogl/cogl-pipeline.h>
    #include <cogl/cogl-pipeline-state.h>
    #include <cogl/cogl-pipeline-layer-state.h>
    #include <cogl/cogl-snippet.h>
    #include <cogl/cogl-framebuffer.h>
    #include <cogl/cogl-onscreen.h>
    ...
    

    On the top got "#if defined (COGL_ENABLE_EXPERIMENTAL_API)". So now i know i have to give it COGL_ENABLE_EXPERIMENTAL_API defined in order to include cogl-onscreen.h.

    Search again with "COGL_ENABLE_EXPERIMENTAL_API" as keyword:

    #ifdef COGL_ENABLE_EXPERIMENTAL_2_0_API
    #ifndef COGL_ENABLE_EXPERIMENTAL_API
    #define COGL_ENABLE_EXPERIMENTAL_API
    #endif
    #endif
    

    That's the end, i need to add -D COGL_ENABLE_EXPERIMENTAL_2_0_API:

    $ gcc -D COGL_ENABLE_EXPERIMENTAL_2_0_API -o hello hello.c `pkg-config --cflags --libs cogl-2.0-experimental`
    

    enter image description here

    Available options for pkg-config can be figure out by autocomplete:

    [xiaobai@xiaobai cogl]$ pkg-config --cflags --libs cogl-[Press Tab]
    cogl-1.0                     cogl-pango-1.0               cogl-path-2.0-experimental
    cogl-2.0-experimental        cogl-pango-2.0-experimental  
    cogl-gl-1.0                  cogl-path-1.0                
    [xiaobai@xiaobai cogl]$