[Piglit] [PATCH 2/2] multisample/formats: Check for spec-complient integer resolves

Jason Ekstrand jason at jlekstrand.net
Wed May 4 23:23:03 UTC 2016


The i965 driver has historically done integer multisample resolves with a
sort of integer averaging operation.  The spec used to not really say
anything at all about integer formats when discussing multisampling.  Since
the tests were written, the spec has been substantially clerified.  The new
rule is that integer MSAA resolves are supposed to pick a single arbitrary
sample for each texel rather than trying to combine them in any way.

Signed-off-by: Jason Ekstrand <jason at jlekstrand.net>
---
 tests/spec/ext_framebuffer_multisample/formats.cpp | 196 ++++++++++++++++-----
 1 file changed, 155 insertions(+), 41 deletions(-)

diff --git a/tests/spec/ext_framebuffer_multisample/formats.cpp b/tests/spec/ext_framebuffer_multisample/formats.cpp
index 4b1feba..1024b45 100644
--- a/tests/spec/ext_framebuffer_multisample/formats.cpp
+++ b/tests/spec/ext_framebuffer_multisample/formats.cpp
@@ -70,6 +70,44 @@ ColorGradientSunburst *test_pattern_vec4;
 ColorGradientSunburst *test_pattern_ivec4;
 ColorGradientSunburst *test_pattern_uvec4;
 
+struct int_resolve_check_s {
+	GLuint prog;
+	GLint u_resolve;
+	GLint u_msaa;
+	GLint u_samples;
+} int_resolve_check;
+
+const char int_resolve_check_vs[] =
+	"#version 130\n"
+	"in vec4 piglit_vertex;\n"
+	"void main() {\n"
+	"	gl_Position = piglit_vertex;\n"
+	"}\n";
+
+/* The OpenGL ES 3.2 and OpenGL 4.4 specs both state:
+ *
+ *	"If the source for- mats are integer types or stencil values, a
+ *	single sample’s value is selected for each pixel."
+ *
+ * This shader checks exactly that condition, namely that the result of the
+ * resolve is exactly one of the sample values in the original image.
+ */
+const char int_resolve_check_fs[] =
+	"#version 130\n"
+	"#extension GL_ARB_texture_multisample: require\n"
+	"uniform isampler2DMS msaa;\n"
+	"uniform isampler2D resolve;\n"
+	"uniform int samples;\n"
+	"void main() {\n"
+	"	gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);\n"
+	"	const vec4 green = vec4(0.0, 1.0, 0.0, 1.0);\n"
+	"	ivec2 pos = ivec2(gl_FragCoord.xy);\n"
+	"	ivec4 res = texelFetch(resolve, pos, 0);\n"
+	"	for (int s = 0; s < samples; s++) {\n"
+	"		if (res == texelFetch(msaa, pos, s))\n"
+	"			gl_FragColor = green;\n"
+	"	}\n"
+	"}\n";
 
 /**
  * This class encapsulates the code necessary to draw the test pattern
@@ -80,7 +118,7 @@ ColorGradientSunburst *test_pattern_uvec4;
 class PatternRenderer
 {
 public:
-	bool try_setup(GLenum internalformat);
+	bool try_setup(GLenum internalformat, bool is_integer);
 	void set_piglit_tolerance();
 	void set_color_clamping_mode();
 	void draw();
@@ -140,11 +178,18 @@ public:
  * incomplete.
  */
 bool
-PatternRenderer::try_setup(GLenum internalformat)
+PatternRenderer::try_setup(GLenum internalformat, bool is_integer)
 {
 	FboConfig config_downsampled(0, pattern_width, pattern_height);
 	config_downsampled.color_internalformat = internalformat;
 
+	if (is_integer) {
+		config_downsampled.color_format = GL_RGBA_INTEGER;
+		config_downsampled.num_rb_attachments = 0;
+		config_downsampled.num_tex_attachments = 1;
+		config_downsampled.use_rect = false;
+	}
+
 	FboConfig config_msaa = config_downsampled;
 	config_msaa.num_samples = num_samples;
 
@@ -497,7 +542,9 @@ test_format(const struct format_desc *format)
 	 * supported, we might have received a GL error.  In either
 	 * case just skip to the next format.
 	 */
-	bool setup_success = test_renderer.try_setup(format->internalformat);
+	bool is_integer = (test_sets[test_index].basetype == GL_INT);
+	bool setup_success = test_renderer.try_setup(format->internalformat,
+						     is_integer);
 	if (glGetError() != GL_NO_ERROR) {
 		printf("Error setting up test renderbuffers\n");
 		return PIGLIT_SKIP;
@@ -511,7 +558,8 @@ test_format(const struct format_desc *format)
 	 * This shouldn't fail.
 	 */
 	setup_success = ref_renderer.try_setup(test_renderer.is_srgb ?
-					       GL_SRGB8_ALPHA8 : GL_RGBA);
+					       GL_SRGB8_ALPHA8 : GL_RGBA,
+					       false);
 	if (!piglit_check_gl_error(GL_NO_ERROR)) {
 		printf("Error setting up reference renderbuffers\n");
 		return PIGLIT_FAIL;
@@ -521,50 +569,99 @@ test_format(const struct format_desc *format)
 		return PIGLIT_FAIL;
 	}
 
-	/* Draw test and reference images, and read them into memory */
-	test_renderer.set_piglit_tolerance();
 	test_renderer.draw();
 	float *test_image =
 		test_renderer.read_image(format->base_internal_format);
-	ref_renderer.draw();
-	float *ref_image = ref_renderer.read_image(GL_RGBA);
-
-	/* Compute the expected image from the reference image */
-	float *expected_image =
-		compute_expected_image(ref_image,
-				       format->base_internal_format);
-
-	/* Check that the test image was correct */
-	unsigned num_components =
-		piglit_num_components(format->base_internal_format);
-	float tolerance[4];
-	piglit_compute_probe_tolerance(format->base_internal_format,
-				       tolerance);
-	pass = piglit_compare_images_color(0, 0, pattern_width, pattern_height,
-					   num_components, tolerance,
-					   expected_image, test_image);
-
-
-	/* Show both the test and expected images on screen so that
-	 * the user can diagnose problems. Pass image_count = 0 to
-	 * display image without any offset applied to raster position.
-	 */
-	glViewport(0, 0, piglit_width, piglit_height);
-	piglit_visualize_image(test_image, format->base_internal_format,
-			       pattern_width, pattern_height,
-			       0 /* image_count */,
-			       false /* rhs */);
-	piglit_visualize_image(expected_image, format->base_internal_format,
-			       pattern_width, pattern_height,
-			       0 /* image_count */,
-			       true /* rhs */);
+
+	if (is_integer) {
+		Fbo compare_fbo;
+		compare_fbo.setup(FboConfig(0, pattern_width, pattern_height));
+
+		glBindFramebuffer(GL_DRAW_FRAMEBUFFER, compare_fbo.handle);
+
+		glUseProgram(int_resolve_check.prog);
+		glUniform1i(int_resolve_check.u_msaa, 0);
+		glUniform1i(int_resolve_check.u_resolve, 1);
+		glUniform1i(int_resolve_check.u_samples, num_samples);
+
+		glActiveTexture(GL_TEXTURE0);
+		glBindTexture(GL_TEXTURE_2D_MULTISAMPLE,
+			      test_renderer.fbo_msaa.color_tex[0]);
+
+		glActiveTexture(GL_TEXTURE1);
+		glBindTexture(GL_TEXTURE_2D,
+			      test_renderer.fbo_downsampled.color_tex[0]);
+
+		glViewport(0, 0, pattern_width, pattern_height);
+		piglit_draw_rect(-1.0, -1.0, 2.0, 2.0);
+
+		glBindFramebuffer(GL_READ_FRAMEBUFFER, compare_fbo.handle);
+
+		const float green[] = { 0.0, 1.0, 0.0, 1.0 };
+		pass = piglit_probe_rect_rgb(0, 0, pattern_width,
+					     pattern_height, green);
+
+		/* Show both the test image and the check result on screen
+		 * so that the user can diagnose problems.
+		 */
+		glViewport(0, 0, piglit_width, piglit_height);
+		piglit_visualize_image(test_image, format->base_internal_format,
+				       pattern_width, pattern_height,
+				       0 /* image_count */,
+				       false /* rhs */);
+
+		glBindFramebuffer(GL_READ_FRAMEBUFFER, compare_fbo.handle);
+		glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
+		glBlitFramebuffer(0, 0, pattern_width, pattern_height,
+				  pattern_width, 0,
+				  pattern_width * 2, pattern_height,
+				  GL_COLOR_BUFFER_BIT, GL_NEAREST);
+	} else {
+		/* Draw test and reference images, and read them into memory */
+		test_renderer.set_piglit_tolerance();
+		ref_renderer.draw();
+		float *ref_image = ref_renderer.read_image(GL_RGBA);
+
+		/* Compute the expected image from the reference image */
+		float *expected_image =
+			compute_expected_image(ref_image,
+					       format->base_internal_format);
+
+		/* Check that the test image was correct */
+		unsigned num_components =
+			piglit_num_components(format->base_internal_format);
+		float tolerance[4];
+		piglit_compute_probe_tolerance(format->base_internal_format,
+					       tolerance);
+		pass = piglit_compare_images_color(0, 0, pattern_width,
+						   pattern_height,
+						   num_components, tolerance,
+						   expected_image, test_image);
+
+
+		/* Show both the test and expected images on screen so that
+		 * the user can diagnose problems. Pass image_count = 0 to
+		 * display image without any offset applied to raster position.
+		 */
+		glViewport(0, 0, piglit_width, piglit_height);
+		piglit_visualize_image(test_image, format->base_internal_format,
+				       pattern_width, pattern_height,
+				       0 /* image_count */,
+				       false /* rhs */);
+		piglit_visualize_image(expected_image,
+				       format->base_internal_format,
+				       pattern_width, pattern_height,
+				       0 /* image_count */,
+				       true /* rhs */);
+
+		free(ref_image);
+		free(expected_image);
+	}
 
 	/* Finally, if any error occurred, count that as a failure. */
 	pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
 
 	free(test_image);
-	free(ref_image);
-	free(expected_image);
 
 	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 }
@@ -613,13 +710,30 @@ piglit_init(int argc, char **argv)
 
 	fbo_formats_init_test_set(test_set,
 				  GL_TRUE /* print_options */);
+
+	bool is_integer = (test_sets[test_index].basetype == GL_INT);
+
 	test_pattern_vec4 = new ColorGradientSunburst(GL_UNSIGNED_NORMALIZED);
 	test_pattern_vec4->compile();
-	if (piglit_get_gl_version() >= 30) {
+	if (is_integer) {
+		piglit_require_gl_version(30);
+		piglit_require_extension("GL_ARB_texture_multisample");
+
 		test_pattern_ivec4 = new ColorGradientSunburst(GL_INT);
 		test_pattern_ivec4->compile();
 		test_pattern_uvec4 = new ColorGradientSunburst(GL_UNSIGNED_INT);
 		test_pattern_uvec4->compile();
+
+		int_resolve_check.prog =
+			piglit_build_simple_program(int_resolve_check_vs,
+						    int_resolve_check_fs);
+		glUseProgram(int_resolve_check.prog);
+		int_resolve_check.u_resolve =
+			glGetUniformLocation(int_resolve_check.prog, "resolve");
+		int_resolve_check.u_msaa =
+			glGetUniformLocation(int_resolve_check.prog, "msaa");
+		int_resolve_check.u_samples =
+			glGetUniformLocation(int_resolve_check.prog, "samples");
 	}
 }
 
-- 
2.5.0.400.gff86faf



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