[Piglit] [PATCH] arb_texture_multisample: add test to check sample positions

Christoph Bumiller christoph.bumiller at speed.at
Sat Apr 6 14:30:38 PDT 2013


From: Christoph Bumiller <e0425955 at student.tuwien.ac.at>

Wrote this to figure out the sample positions on NVC0.
Didn't find any test that checks if the driver reported sample
positions match the behaviour of rendering.

It's probably a bit too crazy, but I thought I'd just send it in
case anyone wants to make use of it.
---
 .../spec/arb_texture_multisample/CMakeLists.gl.txt |    1 +
 .../spec/arb_texture_multisample/sample-position.c |  207 ++++++++++++++++++++
 2 files changed, 208 insertions(+), 0 deletions(-)
 create mode 100644 tests/spec/arb_texture_multisample/sample-position.c

diff --git a/tests/spec/arb_texture_multisample/CMakeLists.gl.txt b/tests/spec/arb_texture_multisample/CMakeLists.gl.txt
index 1339d62..642418f 100644
--- a/tests/spec/arb_texture_multisample/CMakeLists.gl.txt
+++ b/tests/spec/arb_texture_multisample/CMakeLists.gl.txt
@@ -18,5 +18,6 @@ piglit_add_executable (arb_texture_multisample-sample-mask sample-mask.c)
 piglit_add_executable (arb_texture_multisample-sample-mask-value sample-mask-value.c)
 piglit_add_executable (arb_texture_multisample-sample-mask-execution sample-mask-execution.c)
 piglit_add_executable (arb_texture_multisample-negative-max-samples negative-max-samples.c)
+piglit_add_executable (arb_texture_multisample-sample-position sample-position.c)
 
 # vim: ft=cmake:
diff --git a/tests/spec/arb_texture_multisample/sample-position.c b/tests/spec/arb_texture_multisample/sample-position.c
new file mode 100644
index 0000000..d67ad5b
--- /dev/null
+++ b/tests/spec/arb_texture_multisample/sample-position.c
@@ -0,0 +1,207 @@
+/*
+ * Copyright © The Piglit Project 2013
+ *
+ * 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.
+ *
+ * Authors: Christoph Bumiller
+ */
+#include "piglit-util-gl-common.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+    config.supports_gl_core_version = 31;
+    config.window_visual = PIGLIT_GL_VISUAL_RGB;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+#define NUM_STEPS   32
+#define MAX_SAMPLES 32
+
+static GLuint tfb;
+static GLuint buf;
+static GLuint tex;
+static GLuint fbo;
+static GLuint prog;
+
+static int samples = 0;
+
+enum piglit_result
+piglit_display(void)
+{
+	float mspos[MAX_SAMPLES][2];
+	float *res;
+	const float inc = 2.0f / (float)NUM_STEPS;
+	GLint u;
+	unsigned int i, s;
+	GLint test;
+
+	glUseProgram(prog);
+
+	u = glGetUniformLocation(prog, "pos");
+
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, tex);
+
+	for (i = 0; i < samples; ++i)
+		glGetMultisamplefv(GL_SAMPLE_POSITION, i, &mspos[i][0]);
+
+	glUniform1i(glGetUniformLocation(prog, "tex"), 0);
+	glUniform1i(glGetUniformLocation(prog, "num_samples"), samples);
+
+	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
+
+	glBeginTransformFeedback(GL_POINTS);
+	for (i = 0; i < NUM_STEPS; ++i) {
+		glPauseTransformFeedback();
+		glClear(GL_COLOR_BUFFER_BIT);
+		glUniform2f(u, -1.0f + inc * (float)i, -1.0f);
+		glDrawArrays(GL_TRIANGLES, 0, 3);
+		glResumeTransformFeedback();
+
+		glTextureBarrierNV();
+		glEnable(GL_RASTERIZER_DISCARD);
+		glDrawArrays(GL_POINTS, 0, 1);
+		glDisable(GL_RASTERIZER_DISCARD);
+	}
+	for (i = 0; i < NUM_STEPS; ++i) {
+		glPauseTransformFeedback();
+		glClear(GL_COLOR_BUFFER_BIT);
+		glUniform2f(u, -1.0f, -1.0f + inc * (float)i);
+		glDrawArrays(GL_TRIANGLES, 0, 3);
+		glResumeTransformFeedback();
+
+		glTextureBarrierNV();
+		glEnable(GL_RASTERIZER_DISCARD);
+		glDrawArrays(GL_POINTS, 0, 1);
+		glDisable(GL_RASTERIZER_DISCARD);
+	}
+	glEndTransformFeedback();
+
+	res = glMapBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, GL_READ_ONLY);
+
+	for (i = 0; i < NUM_STEPS; ++i) {
+		float p = (float)i / (float)NUM_STEPS;
+
+		int base_x = i * MAX_SAMPLES;
+		int base_y = i * MAX_SAMPLES + NUM_STEPS * MAX_SAMPLES;
+
+		fprintf(stderr, "x >= %f:", p);
+		for (s = 0; s < samples; ++s)
+			if (res[base_x + s] == 1.0f)
+				fprintf(stderr, " %u", s);
+		fprintf(stderr, "\n");
+		fprintf(stderr, "y >= %f:", p);
+		for (s = 0; s < samples; ++s)
+			if (res[base_y + s] == 1.0f)
+				fprintf(stderr, " %u", s);
+		fprintf(stderr, "\n");
+
+		for (s = 0; s < samples; ++s) {
+			if ((p >  mspos[s][0] && res[base_x + s] == 1.0f) ||
+			    (p <= mspos[s][0] && res[base_x + s] != 1.0f))
+				fprintf(stderr, "sample %i x position (%f, %f) "
+					"incorrect !\n",s,
+					mspos[s][0], mspos[s][1]);
+			if ((p >  mspos[s][1] && res[base_y + s] == 1.0f) ||
+			    (p <= mspos[s][1] && res[base_y + s] != 1.0f))
+				fprintf(stderr, "sample %i y position (%f, %f) "
+					"incorrect !\n",s,
+					mspos[s][0], mspos[s][1]);
+		}
+	}
+	glUnmapBuffer(GL_TRANSFORM_FEEDBACK_BUFFER);
+
+	return PIGLIT_PASS;
+}
+
+static const char *vsSource = "#version 140 \n"
+	"#extension GL_ARB_texture_multisample : require\n"
+	"uniform sampler2DMS tex; \n"
+	"uniform int num_samples; \n"
+	"uniform vec2 pos; \n"
+	"out float sample[32]; \n" /* MAX_SAMPLES */
+	"void main() { \n"
+	"   int v = int(gl_VertexID); \n" /* if I can't have immediate mode ... */
+	"   int i; \n"
+	"   gl_Position.xy = pos + 8.0 * vec2(float(v & 1), float(v & 2)); \n"
+	"   gl_Position.zw = vec2(0.0, 1.0); \n"
+	"   for (i = 0; i < 32; ++i) \n"
+	"      sample[i] = texelFetch(tex, ivec2(0, 0), i).g; \n"
+	"} \n";
+
+static const char *fsSource = "#version 140 \n"
+	"void main() { \n"
+	"   gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0); \n"
+	"} \n";
+
+void
+piglit_init(int argc, char **argv)
+{
+	static const char *varyings[] = { "sample" };
+	GLuint vs, fs;
+	GLint test;
+
+	piglit_require_extension("GL_ARB_texture_multisample");
+	piglit_require_extension("GL_NV_texture_barrier");
+
+	if (argc < 2) {
+		fprintf(stderr, "texelFetch <sample_count>\n");
+		exit(0);
+	}
+	samples = strtoul(argv[1], NULL, 0);
+
+	vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vsSource);
+	fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, fsSource);
+	prog = piglit_link_simple_program(vs, fs);
+
+	glGenTransformFeedbacks(1, &tfb);
+	glBindTransformFeedback(GL_TRANSFORM_FEEDBACK, tfb);
+	glTransformFeedbackVaryings(prog, 1, varyings, GL_INTERLEAVED_ATTRIBS);
+	glLinkProgram(prog);
+	glGenBuffers(1, &buf);
+	glBindBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, buf);
+	glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER,
+		     MAX_SAMPLES * sizeof(float) * NUM_STEPS * 2, NULL,
+		     GL_STREAM_DRAW);
+	glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, buf);
+
+	glGenTextures(1, &tex);
+	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, tex);
+	glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, samples,
+				GL_RGBA8,
+				1, 1, GL_TRUE);
+	glGenFramebuffers(1, &fbo);
+	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+			       GL_TEXTURE_2D_MULTISAMPLE, tex, 0);
+
+	glGetIntegerv(GL_SAMPLES, &test);
+	fprintf(stderr, "samples = %u\n", test);
+
+	assert(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE);
+
+	glGetIntegerv(GL_SAMPLES, &test);
+	fprintf(stderr, "samples = %u (post check)\n", test);
+
+	glViewport(0, 0, 1, 1);
+    
+	if (!piglit_check_gl_error(GL_NO_ERROR))
+		piglit_report_result(PIGLIT_FAIL);
+}
-- 
1.7.3.4



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