[Piglit] [PATCH 1/3] util: Add functions that provide glOrtho-like functionality.

[Brian Paul]

On 12/31/2012 12:14 PM, Paul Berry wrote:
> This patch adds functions piglit_gen_ortho_uniform() and
> piglit_ortho_uniform(), which can be used to set up an orthographic
> projection when the legacy function glOrtho() is not available.
>
> The functions work exactly like piglit_gen_ortho_projection() and
> piglit_ortho_projection(), except that instead of programming the
> legacy projection matrix, they program an arbitrary uniform matrix.
> ---
>   tests/util/piglit-util-gl-common.c | 34 ++++++++++++++++++++++++++++++++++
>   tests/util/piglit-util-gl-common.h |  4 ++++
>   2 files changed, 38 insertions(+)
>
> diff --git a/tests/util/piglit-util-gl-common.c b/tests/util/piglit-util-gl-common.c
> index b431815..92a0a4d 100644
> --- a/tests/util/piglit-util-gl-common.c
> +++ b/tests/util/piglit-util-gl-common.c
> @@ -527,3 +527,37 @@ piglit_compressed_pixel_offset(GLenum format, unsigned width,
>
>   	return offset;
>   }
> +
> +
> +#ifndef PIGLIT_USE_OPENGL_ES1
> +/**
> + * Convenience function to configure a shader uniform variable as an
> + * arbitrary orthogonal projection matrix.
> + */
> +void
> +piglit_gen_ortho_uniform(GLint location, double l, double r, double b,
> +			 double t, double n, double f)
> +{
> +	float values[4][4] = {
> +		{ 2/(r-l),    0,        0,    -(r+l)/(r-l) },
> +		{    0,    2/(t-b),     0,    -(t+b)/(t-b) },
> +		{    0,       0,    -2/(f-n), -(f+n)/(f-n) },
> +		{    0,       0,        0,          1      }
> +	};
> +	glUniformMatrix4fv(location, 1, GL_TRUE, values);
> +}
> +
> +
> +/**
> + * Convenience function to configure a shader uniform variable as a
> + * projection matrix for window coordinates.
> + */
> +void
> +piglit_ortho_uniform(GLint location, int w, int h)
> +{
> +        /* Set up projection matrix so we can just draw using window
> +         * coordinates.
> +         */
> +	piglit_gen_ortho_uniform(location, 0, w, 0, h, -1, 1);
> +}
> +#endif
> diff --git a/tests/util/piglit-util-gl-common.h b/tests/util/piglit-util-gl-common.h
> index 2d6bb1a..336953d 100644
> --- a/tests/util/piglit-util-gl-common.h
> +++ b/tests/util/piglit-util-gl-common.h
> @@ -159,6 +159,10 @@ void piglit_gen_ortho_projection(double left, double right, double bottom,
>   void piglit_ortho_projection(int w, int h, GLboolean push);
>   void piglit_frustum_projection(GLboolean push, double l, double r, double b,
>   			       double t, double n, double f);
> +void piglit_gen_ortho_uniform(GLint location, double left, double right,
> +			      double bottom, double top, double near_val,
> +			      double far_val);
> +void piglit_ortho_uniform(GLint location, int w, int h);
>
>   GLuint piglit_checkerboard_texture(GLuint tex, unsigned level,
>       unsigned width, unsigned height,

IMO, the names could be more symetric.  Something like:

piglit_gen_ortho3d_uniform()
piglit_gen_ortho2d_uniform()

but it's not a big deal.

Reviewed-by: Brian Paul <brianp at vmware.com>

-Brian