glGetShaderSource is passed wrong type? (go 1.1 beta2 / tip)

[RStainforth]

When I run the following, it doesn't compile, unless I apply the patch below:

$ go build
# github.com/go-gl/gl
shader.go:38: cannot use _Ctype_GLuint(shader) (type C.GLuint) as type C.GLint in function argument

diff --git a/shader.go b/shader.go
index 8052beb..d1659d2 100644
--- a/shader.go
+++ b/shader.go
@@ -36,7 +36,7 @@ func (shader Shader) GetSource() string {
    if length > 1 {
        log := C.malloc(C.size_t(length + 1))
        defer C.free(log)
-       C.glGetShaderSource(C.GLuint(shader), C.GLsizei(length), nil, (*C.GLchar)(log))
+       C.glGetShaderSource(C.GLint(shader), C.GLsizei(length), nil, (*C.GLchar)(log))
        return C.GoString((*C.char)(log))
    }
    return ""

[vova616]

http://www.opengl.org/sdk/docs/man/xhtml/glGetShaderSource.xml

void glGetShaderSource( GLuint shader, GLsizei bufSize, GLsizei * length, GLchar * source);

it also works ok for me (go 1.1 beta2), what's your os?

[RStainforth]

I am running Scientific Linux 6. With the following:

glew-1.5.5-1.el6.x86_64 glew-devel-1.5.5-1.el6.x86_64

freeglut-2.6.0-1.el6.x86_64 freeglut-devel-2.6.0-1.el6.x86_64

[pwaller]

Pinging the thread since @RStainforth edited his response - Just so you know, if you edit the post it doesn't notify people watching the thread.

[RStainforth]

Just to add which mesa version I have also:

mesa-libGL-devel-9.0-0.7.el6.x86_64 mesa-libGL-devel-9.0-0.7.el6.i686

[vova616]

Sorry for the late response, glGetShaderSource is defined in glew.h and your glew version is pretty old, try using 1.9.0

in glew 1.5.5 ypedef void (GLAPIENTRY * PFNGLGETSHADERSOURCEPROC) (GLint obj, GLsizei maxLength, GLsizei* length, GLchar* source);

and glew 1.9.0 typedef void (GLAPIENTRY * PFNGLGETSHADERSOURCEPROC) (GLuint obj, GLsizei maxLength, GLsizei* length, GLchar* source);

its possible to write a proxy c function and let the c compiler handle the conversion to gluint/glint but I think because the readme specifies that the version of glew should be at least 1.5.8, this is working as intended.

[pwaller]

Hmm. That's unfortunate because this seems to be the most recent version of glew shipped with @RStainforth's operating system, and if you change this one thing, it builds. I'm somewhat tempted to put such a wrapper in.

@banthar, were there other reasons that 1.5.5<=v<1.5.8 are not supported?

[banthar]

In GLEW < 1.5.4 some definitions we use are missing. E.g.: glIsTransformFeedback. I don't know of any other issues.

[lclarkmichalek]

This is affecting me, Arch Linux 32 bit. Glew 1.9.0, mesa 9.1.3.

> grep "PFNGLGETSHADERSOURCEPROC" /usr/include/GL/glew.h
typedef void (GLAPIENTRY * PFNGLGETSHADERSOURCEPROC) (GLint obj, GLsizei maxLength, GLsizei* length, GLchar* source);
> pacman -Qo /usr/include/GL/glew.h
/usr/include/GL/glew.h is owned by glew 1.9.0-2

This is running on an ancient laptop, so that might be related. On another machine (same configuration except 64bit and with more modern graphics) I have no problems.

[pwaller]

@bluepeppers, can you confirm that #106 fixes your problem? If so, I'll merge it.

[lclarkmichalek]

I don't have any code to hand that uses the function, so I can't test that, but it fixes the build for me.

[pwaller]

Thanks, that was what I wanted to know. I've merged #106.

[lclarkmichalek]

Hmm, it seems I may have been building the wrong branch (Could have sworn I checked-out your issue-104 branch), and there seem to be a couple of bugs in the patch. Applying this diff changes resolves all issues for me. Sorry for the inconvenience.

[pwaller]

@bluepeppers Thanks for reporting it quickly. Can you please submit a pull request?

[pwaller]

Thanks @bluepeppers!