[Piglit] [PATCH] primitive-restart-draw-mode: fix failures caused by precision issues

[Brian Paul]

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

On 03/22/2014 12:20 PM, Marek Olšák wrote:
> From: Marek Olšák <marek.olsak at amd.com>
>
> Instead of offsetting the vertex position for the second half of the screen,
> setup both halves as separate viewports.
> ---
>   tests/general/primitive-restart-draw-mode.c | 10 ++++++++--
>   1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/tests/general/primitive-restart-draw-mode.c b/tests/general/primitive-restart-draw-mode.c
> index 9bf47b4..722a440 100644
> --- a/tests/general/primitive-restart-draw-mode.c
> +++ b/tests/general/primitive-restart-draw-mode.c
> @@ -249,20 +249,26 @@ piglit_display(void)
>
>   	glClear(GL_COLOR_BUFFER_BIT);
>   	glUseProgram(prog);
> -	glUniform2f(window_size_loc, piglit_width, piglit_height);
> +	glUniform2f(window_size_loc, piglit_width/2, piglit_height);
>   	glVertexAttribPointer(vertex_attr, 2, GL_FLOAT, GL_FALSE,
>   			      sizeof(vertex_patterns[test->pattern][0]),
>   			      vertex_patterns[test->pattern]);
>   	glEnableVertexAttribArray(vertex_attr);
>
>   	for (col = 0; col < NUM_COLS; col++) {
> +		if (col == 0)
> +			glViewport(0, 0, piglit_width/2, piglit_height);
> +		else
> +			glViewport(piglit_width/2, 0, piglit_width/2, piglit_height);
> +
>   		for (row = 0; row < NUM_ROWS; row++) {
> -			glUniform2f(offset_loc, col * PATTERN_SIZE,
> +			glUniform2f(offset_loc, 0,
>   				    (NUM_ROWS - 1 - row) * PATTERN_SIZE);
>   			draw_pattern(row + 1, col == 0);
>   		}
>   	}
>
> +	glViewport(0, 0, piglit_width, piglit_height);
>   	pass = piglit_probe_rect_halves_equal_rgba(0, 0, piglit_width,
>   						   piglit_height) && pass;
>   	pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
>