Render in Image flipped

benoitlahoz's picture

Hi,

Still working on my plugin, I have a trouble that I remeber I had once in another situation : when I put the consumer patch in a Render In Image, it is automatically flipped vertically.

The patch is rendering vertices in OpenGL like this (very very ugly code, full of mistakes...) :

- (void) renderGLScene:(CGLContextObj)cgl_ctx 
             withWorld:(BLWorld*)world 
           andDrawings:(id)drawings
       backgroundColor:(CGColorRef)color 
{
 
 
 
 
 
   glPushAttrib(GL_COLOR_BUFFER_BIT | GL_TRANSFORM_BIT | GL_VIEWPORT_BIT);
 
 
    GLfloat lWidth[2];
    glGetFloatv(GL_LINE_WIDTH_RANGE, lWidth);
 
 
 
   {
 
        const CGFloat*    colorComponents;
        colorComponents = CGColorGetComponents(color);
 
 
        // Antialias
        // -> le permettre dans le plug-in lui-même
        glEnable (GL_LINE_SMOOTH);
 
        // Blend mode -> permettre de choisir
        glEnable(GL_BLEND);
        glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
 
        glClearColor(colorComponents[0], colorComponents[1], colorComponents[2], colorComponents[3]);
      glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
 
 
      glViewport(0, 0, [world width], [world height]);
 
 
      glMatrixMode(GL_PROJECTION);
      glPushMatrix();
      glLoadIdentity();
 
 
        int ptm = [world ptm];
        double aspect = [world aspectRatio];
 
        glOrtho(-ptm/2. * aspect, ptm/2. * aspect, 
            -ptm/2., ptm/2., 
            -1, 1);
 
 
      glMatrixMode(GL_MODELVIEW);
      glPushMatrix();
 
      glLoadIdentity();
   }
 
 
 
   [self drawBodies:cgl_ctx inWorld:world];
 
    if ([drawings isKindOfClass:[NSArray class]]) {
        if ([drawings count] == 6) {
            [self renderDrawingIn:cgl_ctx inWorld:world withDef:drawings];
        } 
    }
 
 
 
 
   glMatrixMode(GL_MODELVIEW);
   glPopMatrix();
   glMatrixMode(GL_PROJECTION);
   glPopMatrix();
 
 
   glPopAttrib();
    glDisable(GL_BLEND);
    glDisable(GL_LINE_SMOOTH);
 
}

Is there something that I am doing wrong ?

Another trouble : I can't configure a blend mode input that would work properly...

Thanks a lot for your advices !

Ben

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benoitlahoz's picture
Re: Render in Image flipped

Well... So I understood (did I undertsand right ?) that OpenGL renders the vertically beginning by the bottom of the image... Am I right ?

Looking forward to understand how to make my consumer patch appear in the right sense both directly and in a RII... Learning learning... :-)

By the way, thanks so much for everything I learned by here !