[Piglit] [PATCH v2] readpixels-oob: Add a glReadPixels out-of-bounds test

Nanley Chery nanleychery at gmail.com
Wed Feb 17 19:37:23 UTC 2016


From: Nanley Chery <nanley.g.chery at intel.com>

Test that glReadPixels for an area which reaches out of bounds
behaves like a glReadPixels into a sub-rectangle for the valid area.
This behavior reduces the number of corner cases associated with
this function.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92193

Signed-off-by: Nanley Chery <nanley.g.chery at intel.com>

v2 (Brian Paul)
- Rename test and change path
- Use larger window dimensions and compute big buffer dims at runtime
- Use bool instead of GLboolean
- Remove extra function arguments
- Free allocated data
- Exercise more clipping code
---
 tests/all.py                        |   1 +
 tests/spec/gl-1.0/CMakeLists.gl.txt |   1 +
 tests/spec/gl-1.0/readpixels-oob.c  | 132 ++++++++++++++++++++++++++++++++++++
 3 files changed, 134 insertions(+)
 create mode 100644 tests/spec/gl-1.0/readpixels-oob.c

diff --git a/tests/all.py b/tests/all.py
index 89288a2..bb7c1dc 100644
--- a/tests/all.py
+++ b/tests/all.py
@@ -997,6 +997,7 @@ with profile.group_manager(
     g(['gl-1.0-edgeflag-const'])
     g(['gl-1.0-edgeflag-quads'])
     g(['gl-1.0-long-dlist'])
+    g(['gl-1.0-readpixels-oob'])
     g(['gl-1.0-rendermode-feedback'])
     g(['gl-1.0-front-invalidate-back'], run_concurrent=False)
     g(['gl-1.0-swapbuffers-behavior'], run_concurrent=False)
diff --git a/tests/spec/gl-1.0/CMakeLists.gl.txt b/tests/spec/gl-1.0/CMakeLists.gl.txt
index 6ef9059..e1c534c 100644
--- a/tests/spec/gl-1.0/CMakeLists.gl.txt
+++ b/tests/spec/gl-1.0/CMakeLists.gl.txt
@@ -26,6 +26,7 @@ piglit_add_executable (gl-1.0-polygon-line-aa polygon-line-aa.c)
 piglit_add_executable (gl-1.0-push-no-attribs push-no-attribs.c)
 piglit_add_executable (gl-1.0-rastercolor rastercolor.c)
 piglit_add_executable (gl-1.0-readpixsanity readpix.c)
+piglit_add_executable (gl-1.0-readpixels-oob readpixels-oob.c)
 piglit_add_executable (gl-1.0-rendermode-feedback rendermode-feedback.c)
 piglit_add_executable (gl-1.0-swapbuffers-behavior swapbuffers-behavior.c)
 
diff --git a/tests/spec/gl-1.0/readpixels-oob.c b/tests/spec/gl-1.0/readpixels-oob.c
new file mode 100644
index 0000000..44c0340
--- /dev/null
+++ b/tests/spec/gl-1.0/readpixels-oob.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright © 2016 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.
+ *
+ */
+
+/** @file readpixels-oob.c
+ *
+ * Test that requesting an area larger than the readbuffer (with
+ * glReadPixels) will only modify the valid area in the user's buffer.
+ * This is equivalent to a user requesting to read into a sub-rectangle
+ * of the larger rectangle contained in the provided buffer (via
+ * PACK_ROW_LENGTH, PACK_SKIP_ROWS, PACK_SKIP_PIXELS).
+ *
+ * This behaviour ensures that Mesa does as little work as possible in
+ * this imprecise usage of glReadpixels. It also reduces the bugs that
+ * may occur with this special case by converting it to an analogous
+ * common case.
+ *
+ */
+
+#include "piglit-util-gl.h"
+
+#define BIG_MULT 3
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+	config.supports_gl_compat_version = 10;
+	config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+static bool
+test_with_offsets(GLint x_offset, GLint y_offset)
+{
+	bool pass = true;
+	int x, y, i;
+
+	/* Allocate into an oversized buffer. We'll check that the contents
+	 * are still 0 after the glReadPixels.
+	 */
+	const size_t num_chan = 4;
+	const size_t big_buf_h = piglit_height * BIG_MULT;
+	const size_t big_buf_w = piglit_width * BIG_MULT;
+	const size_t tot_elements = big_buf_h * big_buf_w * num_chan;
+	const size_t fb_w = piglit_width - MAX2(0, x_offset);
+	const size_t fb_h = piglit_height - MAX2(0, y_offset);
+	const unsigned dst_x = abs(MIN2(0, x_offset));
+	const unsigned dst_y = abs(MIN2(0, y_offset));
+	GLubyte * black_img = (GLubyte*)calloc(tot_elements, sizeof(GLubyte));
+	GLfloat * black_imgf = (GLfloat*)malloc(tot_elements *sizeof(GLfloat));
+
+	printf("Testing with offsets, x: %d\ty: %d\n", x_offset, y_offset);
+
+	/* Clear background to purple */
+	glClearColor(1.0, 0.0, 1.0, 0.0);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	/* Perform over-sized glReadPixels. Read the readbuffer as
+	 * GLubytes in order to hit most HW fast-paths.
+	 */
+	glReadPixels(x_offset, y_offset, big_buf_w, big_buf_h,
+		     GL_RGBA, GL_UNSIGNED_BYTE, black_img);
+
+	/* Convert values to float in order to use utility comparison function.
+	 */
+	for (i = 0; i < tot_elements; i++)
+		black_imgf[i] = black_img[i] / 255.0;
+
+	/* Confirm the result */
+	for (y = 0; y < big_buf_h; y++) {
+		for (x = 0; x < big_buf_w; x++) {
+			static const GLfloat valid_pixel[4] = {1.0, 0, 1.0, 0};
+			static const GLfloat invalid_pixel[4] = {0};
+			const unsigned index = y * big_buf_w * num_chan +
+						x * num_chan;
+			const GLfloat * expected_pixel =
+					((x >= dst_x  &&
+					  x < fb_w + dst_x) &&
+					 (y >= dst_y &&
+					  y < fb_h + dst_y)) ?
+						valid_pixel : invalid_pixel;
+
+			pass &= piglit_compare_pixels(x, y, expected_pixel,
+						      black_imgf + index,
+						      piglit_tolerance,
+						      num_chan);
+			if (!pass)
+				goto end;
+		}
+	}
+	
+end:
+	free(black_img);
+	free(black_imgf);
+
+	return pass;
+}
+
+enum piglit_result
+piglit_display(void)
+{
+	bool pass = test_with_offsets(0, 0);
+	pass &= test_with_offsets(-piglit_width, 0);
+	pass &= test_with_offsets(0, -piglit_height);
+	pass &= test_with_offsets(-piglit_width, -piglit_height);
+	pass &= test_with_offsets(piglit_width/2, piglit_height/2);
+	piglit_present_results();
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
+
+void piglit_init(int argc, char **argv)
+{
+}
-- 
2.7.1



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