_tnl_vertex_cull_stage

run_cull_stage

static GLboolean run_cull_stage	(	GLcontext *	ctx,
		struct tnl_pipeline_stage *	stage
	)		`[static]`

Definition at line 46 of file t_vb_cull.c.

{
   TNLcontext *tnl = TNL_CONTEXT(ctx);
   struct vertex_buffer *VB = &tnl->vb;

   const GLfloat a = ctx->Transform.CullObjPos[0];
   const GLfloat b = ctx->Transform.CullObjPos[1];
   const GLfloat c = ctx->Transform.CullObjPos[2];
   GLfloat *norm = (GLfloat *)VB->AttribPtr[_TNL_ATTRIB_NORMAL]->data;
   GLuint stride = VB->AttribPtr[_TNL_ATTRIB_NORMAL]->stride;
   GLuint count = VB->Count;
   GLuint i;

   if (ctx->VertexProgram._Current ||
       !ctx->Transform.CullVertexFlag) 
      return GL_TRUE;

   VB->ClipOrMask &= ~CLIP_CULL_BIT;
   VB->ClipAndMask |= CLIP_CULL_BIT;

   for (i = 0 ; i < count ; i++) {
      GLfloat dp = (norm[0] * a + 
            norm[1] * b +
            norm[2] * c);

      if (dp < 0) {
     VB->ClipMask[i] |= CLIP_CULL_BIT;
     VB->ClipOrMask |= CLIP_CULL_BIT;
      }
      else {
     VB->ClipMask[i] &= ~CLIP_CULL_BIT;
     VB->ClipAndMask &= ~CLIP_CULL_BIT;
      }

      STRIDE_F(norm, stride);
   }

   return !(VB->ClipAndMask & CLIP_CULL_BIT);
}

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