[cairo] [PATCH 2/2] gl: Remove GL fixed-function matrix usage.

Alexandros Frantzis alexandros.frantzis at linaro.org
Tue Feb 1 01:38:15 PST 2011

On Mon, Jan 31, 2011 at 08:20:00PM -0800, Eric Anholt wrote:
> No significant performance difference (though a simpler diff showed a
> 2% hit)
> +    double dest_x1 = x1, dest_y1 = y1, dest_x2 = x2, dest_y2 = y2;
> +
> +    cairo_matrix_transform_point (&ctx->dest_matrix, &dest_x1, &dest_y1);
> +    cairo_matrix_transform_point (&ctx->dest_matrix, &dest_x2, &dest_y2);
> +

Hi Eric,

my alternative take on this can be found in the WIP branch


I am using a ModelViewProjectionMatrix custom uniform to pass the
transformation to the shader.

I am tempted to say that my approach may be more efficient, as the per
vertex tranformation is happening in the GPU instead of the CPU.
However, I haven't benchmarked this yet, so I 'll wait until I have more
information before I make any bold statements.


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