[Mesa-dev] [PATCH 23/26] glsl: add determinant() functions.

[Kenneth Graunke]

On 11/30/2012 10:07 AM, Ian Romanick wrote:
> From: Paul Berry <stereotype441 at gmail.com>
>
> These functions are defined in GLSL 1.50 and GLES 3.00 ES.
>
> The formulas have been extracted from the existing implementation of
> inverse().
>
> Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>
> ---
>   src/glsl/builtins/glsl/determinant.glsl | 70 +++++++++++++++++++++++++++++++++
>   1 file changed, 70 insertions(+)
>   create mode 100644 src/glsl/builtins/glsl/determinant.glsl
>
> diff --git a/src/glsl/builtins/glsl/determinant.glsl b/src/glsl/builtins/glsl/determinant.glsl
> new file mode 100644
> index 0000000..32695a8
> --- /dev/null
> +++ b/src/glsl/builtins/glsl/determinant.glsl
> @@ -0,0 +1,70 @@
> +/*
> + * Copyright © 2012 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> + * DEALINGS IN THE SOFTWARE.
> + */
> +
> +#version 120
> +float determinant(mat2 m)
> +{
> +   return m[0][0] * m[1][1] - m[1][0] * m[0][1];
> +}
> +
> +float determinant(mat3 m)
> +{
> +   return (+ m[0][0] * (m[1][1] * m[2][2] - m[1][2] * m[2][1])
> +           - m[0][1] * (m[1][0] * m[2][2] - m[1][2] * m[2][0])
> +           + m[0][2] * (m[1][0] * m[2][1] - m[1][1] * m[2][0]));
> +}
> +
> +float determinant(mat4 m)
> +{
> +   float SubFactor00 = m[2][2] * m[3][3] - m[3][2] * m[2][3];
> +   float SubFactor01 = m[2][1] * m[3][3] - m[3][1] * m[2][3];
> +   float SubFactor02 = m[2][1] * m[3][2] - m[3][1] * m[2][2];
> +   float SubFactor03 = m[2][0] * m[3][3] - m[3][0] * m[2][3];
> +   float SubFactor04 = m[2][0] * m[3][2] - m[3][0] * m[2][2];
> +   float SubFactor05 = m[2][0] * m[3][1] - m[3][0] * m[2][1];
> +   float SubFactor06 = m[1][2] * m[3][3] - m[3][2] * m[1][3];
> +   float SubFactor07 = m[1][1] * m[3][3] - m[3][1] * m[1][3];
> +   float SubFactor08 = m[1][1] * m[3][2] - m[3][1] * m[1][2];
> +   float SubFactor09 = m[1][0] * m[3][3] - m[3][0] * m[1][3];
> +   float SubFactor10 = m[1][0] * m[3][2] - m[3][0] * m[1][2];
> +   float SubFactor11 = m[1][1] * m[3][3] - m[3][1] * m[1][3];
> +   float SubFactor12 = m[1][0] * m[3][1] - m[3][0] * m[1][1];
> +   float SubFactor13 = m[1][2] * m[2][3] - m[2][2] * m[1][3];
> +   float SubFactor14 = m[1][1] * m[2][3] - m[2][1] * m[1][3];
> +   float SubFactor15 = m[1][1] * m[2][2] - m[2][1] * m[1][2];
> +   float SubFactor16 = m[1][0] * m[2][3] - m[2][0] * m[1][3];
> +   float SubFactor17 = m[1][0] * m[2][2] - m[2][0] * m[1][2];
> +   float SubFactor18 = m[1][0] * m[2][1] - m[2][0] * m[1][1];
> +
> +   vec4 adj_0;
> +
> +   adj_0[0] = + (m[1][1] * SubFactor00 - m[1][2] * SubFactor01 + m[1][3] * SubFactor02);
> +   adj_0[1] = - (m[1][0] * SubFactor00 - m[1][2] * SubFactor03 + m[1][3] * SubFactor04);
> +   adj_0[2] = + (m[1][0] * SubFactor01 - m[1][1] * SubFactor03 + m[1][3] * SubFactor05);
> +   adj_0[3] = - (m[1][0] * SubFactor02 - m[1][1] * SubFactor04 + m[1][2] * SubFactor05);
> +
> +   return (+ m[0][0] * adj_0[0]
> +           + m[0][1] * adj_0[1]
> +           + m[0][2] * adj_0[2]
> +           + m[0][3] * adj_0[3]);
> +}
>

I only reviewed the mat2 and mat3 formulas.  I trust the math for 4x4 is 
right and has been tested somehow.

Except where I've expressed objections, this entire series is now:
Reviewed-by: Kenneth Graunke ,kenneth at whitecape.org>