static void apply_stencil_op_to_pixels	(	GLcontext *	ctx,
		GLuint	n,
		const GLint	x[],
		const GLint	y[],
		GLenum	oper,
		GLuint	face,
		const GLubyte	mask[]
	)		`[static]`

Apply the given stencil operator for each pixel in the array whose mask flag is set.

Note:: This is for software stencil buffers only. Input: n - number of pixels in the span x, y - array of [n] pixels operator - the stencil buffer operator mask - array [n] of flag: 1=apply operator, 0=don't apply operator

Definition at line 532 of file s_stencil.c.

Referenced by stencil_and_ztest_pixels(), and stencil_test_pixels().

{
   struct gl_framebuffer *fb = ctx->DrawBuffer;
   struct gl_renderbuffer *rb = fb->_StencilBuffer;
   const GLstencil stencilMax = (1 << fb->Visual.stencilBits) - 1;
   const GLstencil ref = ctx->Stencil.Ref[face];
   const GLstencil wrtmask = ctx->Stencil.WriteMask[face];
   const GLstencil invmask = (GLstencil) (~wrtmask);
   GLuint i;
   GLstencil *stencilStart = (GLubyte *) rb->Data;
   const GLuint stride = rb->Width;

   ASSERT(rb->GetPointer(ctx, rb, 0, 0));
   ASSERT(sizeof(GLstencil) == 1);

   switch (oper) {
      case GL_KEEP:
         /* do nothing */
         break;
      case GL_ZERO:
     if (invmask==0) {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
                  *sptr = 0;
           }
        }
     }
     else {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
          *sptr = (GLstencil) (invmask & *sptr);
           }
        }
     }
     break;
      case GL_REPLACE:
     if (invmask==0) {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
                  *sptr = ref;
           }
        }
     }
     else {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
          *sptr = (GLstencil) ((invmask & *sptr ) | (wrtmask & ref));
           }
        }
     }
     break;
      case GL_INCR:
     if (invmask==0) {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
          if (*sptr < stencilMax) {
             *sptr = (GLstencil) (*sptr + 1);
          }
           }
        }
     }
     else {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
          if (*sptr < stencilMax) {
             *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr+1)));
          }
           }
        }
     }
     break;
      case GL_DECR:
     if (invmask==0) {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
          if (*sptr>0) {
             *sptr = (GLstencil) (*sptr - 1);
          }
           }
        }
     }
     else {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
          if (*sptr>0) {
             *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr-1)));
          }
           }
        }
     }
     break;
      case GL_INCR_WRAP_EXT:
     if (invmask==0) {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
                  *sptr = (GLstencil) (*sptr + 1);
           }
        }
     }
     else {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
                  *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr+1)));
           }
        }
     }
     break;
      case GL_DECR_WRAP_EXT:
     if (invmask==0) {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
                  *sptr = (GLstencil) (*sptr - 1);
           }
        }
     }
     else {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
                  *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr-1)));
           }
        }
     }
     break;
      case GL_INVERT:
     if (invmask==0) {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
                  *sptr = (GLstencil) (~*sptr);
           }
        }
     }
     else {
        for (i=0;i<n;i++) {
           if (mask[i]) {
                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
                  *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & ~*sptr));
           }
        }
     }
     break;
      default:
         _mesa_problem(ctx, "Bad stencilop in apply_stencil_op_to_pixels");
   }
}

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