[Piglit] [PATCH] getteximage-formats: Add option to clear texture before rendering

[Brian Paul]

On 02/11/2016 10:11 AM, Topi Pohjolainen wrote:
> Demonstrates a bug in Intel color resolve logic. If rendering to
> texture is preceded by fast clear subsequent reads from the
> texture require the underlying color buffer to be resolved. In
> case of mipmap generation Intel driver needs to reallocate the
> underlying buffer to fit the subsequent levels. However, copy of
> the original level zero to newly allocated buffer is delayed until
> the driver is about to generate level one using level zero as
> source. This causes a color resolve of the original level zero.
> Both the generation of level one and the resolve are meta
> operations, and the latter will interfere with the sampler
> settings of the former.
>
> Signed-off-by: Topi Pohjolainen <topi.pohjolainen at intel.com>
> CC: Ian Romanick <idr at freedesktop.org>
> ---
>   tests/all.py                          |  1 +
>   tests/texturing/getteximage-formats.c | 16 +++++++++++++---
>   2 files changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/tests/all.py b/tests/all.py
> index 2912d1f..8938bfc 100644
> --- a/tests/all.py
> +++ b/tests/all.py
> @@ -2987,6 +2987,7 @@ with profile.group_manager(
>       g(['fbo-storage-completeness'])
>       g(['fbo-storage-formats'])
>       g(['getteximage-formats', 'init-by-rendering'])
> +    g(['getteximage-formats', 'init-by-clear-and-render'])
>       g(['ext_framebuffer_multisample-fast-clear', 'single-sample'],
>         'fbo-fast-clear')
>       add_fbo_stencil_tests(g, 'GL_STENCIL_INDEX1')
> diff --git a/tests/texturing/getteximage-formats.c b/tests/texturing/getteximage-formats.c
> index 715d5df..320683f 100644
> --- a/tests/texturing/getteximage-formats.c
> +++ b/tests/texturing/getteximage-formats.c
> @@ -50,6 +50,7 @@ static const char *TestName = "getteximage-formats";
>   static const GLfloat clearColor[4] = { 0.4, 0.4, 0.4, 0.0 };
>   static GLuint texture_id;
>   static GLboolean init_by_rendering;
> +static GLboolean init_by_clearing_first;
>
>   #define TEX_SIZE 128
>
> @@ -83,7 +84,7 @@ make_texture_image(GLenum intFormat, GLubyte upperRightTexel[4])
>
>   	memcpy(upperRightTexel, tex[TEX_SIZE-1][TEX_SIZE-1], 4);
>
> -	if (init_by_rendering) {
> +	if (init_by_rendering || init_by_clearing_first) {
>   		/* Initialize the mipmap levels. */
>   		for (i = TEX_SIZE, j = 0; i; i >>= 1, j++) {
>   			glTexImage2D(GL_TEXTURE_2D, j, intFormat, i, i, 0,
> @@ -102,6 +103,11 @@ make_texture_image(GLenum intFormat, GLubyte upperRightTexel[4])
>   			return GL_FALSE;
>   		}
>
> +		if (init_by_clearing_first) {
> +			glClearColor(1, 0, 0, 1);
> +			glClear(GL_COLOR_BUFFER_BIT);
> +		}
> +
>   		glViewport(0, 0, TEX_SIZE, TEX_SIZE);
>
>   		glWindowPos2iARB(0, 0);
> @@ -365,6 +371,7 @@ test_format(const struct test_desc *test,
>   	GLfloat expected[4], pix[4], tolerance[4];
>   	GLboolean pass = GL_TRUE;
>
> +	glClearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
>   	glClear(GL_COLOR_BUFFER_BIT);
>
>   	/* The RGBA_DXT1 formats seem to expose a Mesa/libtxc_dxtn bug.
> @@ -536,6 +543,11 @@ piglit_init(int argc, char **argv)
>   			puts("The textures will be initialized by rendering "
>   			     "to them using glDrawPixels.");
>   			break;
> +		} else if (strcmp(argv[i], "init-by-clear-and-render") == 0) {
> +			init_by_clearing_first = GL_TRUE;
> +			puts("The textures will be initialized by rendering "
> +			     "to them using glCear and glDrawPixels.");
> +			break;
>   		}
>   	}
>
> @@ -547,6 +559,4 @@ piglit_init(int argc, char **argv)
>   	glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
>
>   	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
> -
> -	glClearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
>   }
>

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