Test that MSAA blits work properly even when unaligned.

This test verifies that blits involving MSAA buffers work properly
even if the source and destination rectangles are located in different
parts of their respective framebuffers, and even if the source and
destination rectangles are not aligned to powers of two.

These are necessary corner cases to check in i965, where blits that
involve MSAA buffers frequently require special handling when the
source and destination rectangles are different, or are not nicely
aligned.

v2: Use a tile size of 49 instead of 50, so that source and
destination rectangles are even more poorly aligned.  This exposed a
bug in i965/gen6.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

3 files changed, 239 insertions, 0 deletions

diff --git a/tests/all.tests b/tests/all.tests
index aaeb809d0..9f3717335 100644
--- a/tests/all.tests
+++ b/tests/all.tests
@@ -1336,6 +1336,14 @@ for num_samples in (2, 4, 8, 16, 32):
                         test_name)
                 ext_framebuffer_multisample[test_name] = PlainExecTest(executable)
 
+for num_samples in (2, 4, 8, 16, 32):
+        for buffer_type in ('color', 'depth', 'stencil'):
+                for blit_type in ('msaa', 'upsample', 'downsample'):
+                        test_name = ' '.join(['unaligned-blit', str(num_samples), buffer_type, blit_type])
+                        executable = 'ext_framebuffer_multisample-{0} -auto'.format(
+                                test_name)
+                        ext_framebuffer_multisample[test_name] = PlainExecTest(executable)
+
 ext_framebuffer_object = Group()
 spec['EXT_framebuffer_object'] = ext_framebuffer_object
 add_fbo_stencil_tests(ext_framebuffer_object, 'GL_STENCIL_INDEX1')
diff --git a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
index 475237c44..c10043c9e 100644
--- a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
+++ b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
@@ -24,4 +24,5 @@ piglit_add_executable (ext_framebuffer_multisample-renderbuffer-samples renderbu
 piglit_add_executable (ext_framebuffer_multisample-renderbufferstorage-samples renderbufferstorage-samples.c)
 piglit_add_executable (ext_framebuffer_multisample-samples samples.c)
 piglit_add_executable (ext_framebuffer_multisample-turn-on-off common.cpp turn-on-off.cpp)
+piglit_add_executable (ext_framebuffer_multisample-unaligned-blit common.cpp unaligned-blit.cpp)
 piglit_add_executable (ext_framebuffer_multisample-upsample common.cpp upsample.cpp)
diff --git a/tests/spec/ext_framebuffer_multisample/unaligned-blit.cpp b/tests/spec/ext_framebuffer_multisample/unaligned-blit.cpp
new file mode 100644
index 000000000..5d1f82878
--- /dev/null
+++ b/tests/spec/ext_framebuffer_multisample/unaligned-blit.cpp
@@ -0,0 +1,230 @@
+/*
+ * Copyright © 2012 Intel Corporation
+ *
+ * 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.
+ */
+#include "common.h"
+
+/**
+ * \file unaligned-blit.cpp
+ *
+ * Verify the accuracy of blits involving MSAA buffers when the blit
+ * coordinates are not aligned to simple powers of two.
+ *
+ * This test operates through the use of a sequence of blits that
+ * might be called a "scrambling blit": a source image (whose size is
+ * not a power of two) is divided up into tiles (whose size is also
+ * not a power of two), and these tiles are blitted one at a time from
+ * the source to the destination buffer, permuting the order of the
+ * tiles in a deterministic way.  The scrambling ensures that we test
+ * a wide variety of different offsets and coordinate misalignments.
+ *
+ * The test performs the following operations: First an unscrambled
+ * test image is created in a source buffer, which may or may not be
+ * multisampled.  Then a scrambling blit is used to copy it to a
+ * destination buffer, which also may or may not be multisampled.
+ * Finally, the destination buffer is blitted to the window system
+ * framebuffer, using the inverse permutation.  This should result in
+ * an unscrambled test image.
+ *
+ * To verify that the test image is correct, we produce a reference
+ * image by repeating the same operation using ordinary unscrambled
+ * blits.
+ */
+const int pattern_size = 245;
+const int tile_size = 49;
+const int tiles_across = 5;
+const int num_tiles = tiles_across * tiles_across;
+
+int piglit_width = pattern_size * 2; int piglit_height = pattern_size;
+int piglit_window_mode =
+	GLUT_DOUBLE | GLUT_RGBA | GLUT_ALPHA | GLUT_DEPTH | GLUT_STENCIL;
+
+
+const int permutation[num_tiles] = {
+	10, 5, 6, 17, 3, 11, 16, 21, 14, 24, 23, 8, 15, 18, 0, 12, 9,
+	4, 22, 19, 20, 2, 7, 13, 1
+};
+
+const int inverse_permutation[num_tiles] = {
+	14, 24, 21, 4, 17, 1, 2, 22, 11, 16, 0, 5, 15, 23, 8, 12, 6,
+	3, 13, 19, 20, 7, 18, 10, 9
+};
+
+Fbo src_fbo;
+Fbo dst_fbo;
+TestPattern *test_pattern = NULL;
+ManifestProgram *manifest_program = NULL;
+GLbitfield buffer_to_test;
+
+void
+scrambling_blit(const int *permutation)
+{
+	for (int i = 0; i < num_tiles; ++i) {
+		int src_x = (i % tiles_across) * tile_size;
+		int src_y = (i / tiles_across) * tile_size;
+		int dst_x = (permutation[i] % tiles_across) * tile_size;
+		int dst_y = (permutation[i] / tiles_across) * tile_size;
+		glBlitFramebuffer(src_x, src_y,
+				  src_x + tile_size, src_y + tile_size,
+				  dst_x, dst_y,
+				  dst_x + tile_size, dst_y + tile_size,
+				  buffer_to_test, GL_NEAREST);
+	}
+}
+
+void
+print_usage_and_exit(char *prog_name)
+{
+	printf("Usage: %s <num_samples> <buffer_type> <blit_type>\n"
+	       "  where <buffer_type> is one of:\n"
+	       "    color\n"
+	       "    stencil\n"
+	       "    depth\n"
+	       "  and <blit_type> is one of:\n"
+	       "    msaa\n"
+	       "    upsample\n"
+	       "    downsample\n",
+	       prog_name);
+	piglit_report_result(PIGLIT_FAIL);
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+	int num_samples;
+	int src_samples;
+	int dst_samples;
+	if (argc < 4)
+		print_usage_and_exit(argv[0]);
+
+	char *endptr = NULL;
+	num_samples = strtol(argv[1], &endptr, 0);
+	if (endptr != argv[1] + strlen(argv[1]))
+		print_usage_and_exit(argv[0]);
+
+	piglit_require_gl_version(30);
+
+	/* Skip the test if num_samples > GL_MAX_SAMPLES */
+	GLint max_samples;
+	glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
+	if (num_samples > max_samples)
+		piglit_report_result(PIGLIT_SKIP);
+
+	if (strcmp(argv[2], "color") == 0) {
+		test_pattern = new Triangles();
+		buffer_to_test = GL_COLOR_BUFFER_BIT;
+	} else if (strcmp(argv[2], "depth") == 0) {
+		test_pattern = new DepthSunburst();
+		manifest_program = new ManifestDepth();
+		buffer_to_test = GL_DEPTH_BUFFER_BIT;
+	} else if (strcmp(argv[2], "stencil") == 0) {
+		test_pattern = new StencilSunburst();
+		manifest_program = new ManifestStencil();
+		buffer_to_test = GL_STENCIL_BUFFER_BIT;
+	} else {
+		print_usage_and_exit(argv[0]);
+	}
+
+	if (strcmp(argv[3], "msaa") == 0) {
+		src_samples = dst_samples = num_samples;
+	} else if (strcmp(argv[3], "upsample") == 0) {
+		src_samples = 0;
+		dst_samples = num_samples;
+	} else if (strcmp(argv[3], "downsample") == 0) {
+		src_samples = num_samples;
+		dst_samples = 0;
+	} else {
+		print_usage_and_exit(argv[0]);
+	}
+
+	test_pattern->compile();
+	if (manifest_program)
+		manifest_program->compile();
+	src_fbo.init(src_samples, pattern_size, pattern_size,
+		     true /* combine_depth_stencil */,
+		     false /* attach_texture */);
+	dst_fbo.init(dst_samples, pattern_size, pattern_size,
+		     true /* combine_depth_stencil */,
+		     false /* attach_texture */);
+}
+
+enum piglit_result
+piglit_display()
+{
+	bool pass = true;
+
+	/* Draw the test pattern in src_fbo. */
+	float proj[4][4] = {
+		{ 1, 0, 0, 0 },
+		{ 0, 1, 0, 0 },
+		{ 0, 0, 1, 0 },
+		{ 0, 0, 0, 1 }
+	};
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, src_fbo.handle);
+	src_fbo.set_viewport();
+	test_pattern->draw(proj);
+
+	/* Blit from src_fbo to dst_fbo, scrambling the pattern as we go. */
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, src_fbo.handle);
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, dst_fbo.handle);
+	scrambling_blit(permutation);
+
+	/* Blit from dst_fbo to the left half of the window system
+	 * framebuffer, unscrambling as we go.
+	 */
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, dst_fbo.handle);
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+	scrambling_blit(inverse_permutation);
+
+	/* Blit from src_fbo to dst_fbo with no scrambling. */
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, src_fbo.handle);
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, dst_fbo.handle);
+	glBlitFramebuffer(0, 0, pattern_size, pattern_size,
+			  0, 0, pattern_size, pattern_size,
+			  buffer_to_test, GL_NEAREST);
+
+	/* Blit from dst_fbo to the right half of the window system
+	 * framebuffer, with no scrambling.
+	 */
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, dst_fbo.handle);
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+	glBlitFramebuffer(0, 0, pattern_size, pattern_size,
+			  pattern_size, 0, pattern_size*2, pattern_size,
+			  buffer_to_test, GL_NEAREST);
+
+	/* If we were testing depth or stencil, manifest the image so
+	 * that we can see it.
+	 */
+	glViewport(0, 0, piglit_width, piglit_height);
+	if (manifest_program)
+		manifest_program->run();
+
+	/* Check that the left and right halves of the screen match. */
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
+	pass = piglit_probe_rect_halves_equal_rgba(0, 0, piglit_width,
+						   piglit_height) && pass;
+
+	pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
+
+	piglit_present_results();
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}