[Piglit] [PATCH 1/2] readpix-z: test glReadPixels(GL_DEPTH_COMPONENT)

[Brian Paul]

---
 tests/all.tests                 |    1 +
 tests/general/CMakeLists.gl.txt |    1 +
 tests/general/readpix-z.c       |  113 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 115 insertions(+), 0 deletions(-)
 create mode 100644 tests/general/readpix-z.c

diff --git a/tests/all.tests b/tests/all.tests
index 9d6be77..68270f4 100644
--- a/tests/all.tests
+++ b/tests/all.tests
@@ -315,6 +315,7 @@ add_plain_test(general, 'provoking-vertex')
 add_plain_test(general, 'oes-read-format')
 add_plain_test(general, 'quad-invariance')
 add_plain_test(general, 'read-front')
+add_plain_test(general, 'readpix-z')
 add_plain_test(general, 'roundmode-getintegerv')
 add_plain_test(general, 'roundmode-pixelstore')
 add_plain_test(general, 'scissor-bitmap')
diff --git a/tests/general/CMakeLists.gl.txt b/tests/general/CMakeLists.gl.txt
index b2213c4..2318709 100644
--- a/tests/general/CMakeLists.gl.txt
+++ b/tests/general/CMakeLists.gl.txt
@@ -90,6 +90,7 @@ piglit_add_executable (primitive-restart primitive-restart.c)
 piglit_add_executable (provoking-vertex provoking-vertex.c)
 piglit_add_executable (oes-read-format oes-read-format.c)
 piglit_add_executable (read-front read-front.c)
+piglit_add_executable (readpix-z readpix-z.c)
 IF (NOT MSVC)
 	piglit_add_executable (roundmode-getintegerv roundmode-getintegerv.c)
 ENDIF (NOT MSVC)
diff --git a/tests/general/readpix-z.c b/tests/general/readpix-z.c
new file mode 100644
index 0000000..5186768
--- /dev/null
+++ b/tests/general/readpix-z.c
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2012 VMware, Inc.
+ *
+ * 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.
+ */
+
+/**
+ * Test glReadPixels(GL_DEPTH_COMPONENT)
+ * Brian Paul
+ * June 2012
+ */
+
+#include "piglit-util.h"
+
+int piglit_width = 200, piglit_height = 200;
+int piglit_window_mode = GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH;
+
+
+
+static void
+draw_z_gradient(GLfloat zLeft, GLfloat zRight)
+{
+	GLfloat verts[4][3];
+
+	verts[0][0] = -1.0;  verts[0][1] = -1.0;  verts[0][2] = zLeft;
+	verts[1][0] =  1.0;  verts[1][1] = -1.0;  verts[1][2] = zRight;
+	verts[2][0] =  1.0;  verts[2][1] =  1.0;  verts[2][2] = zRight;
+	verts[3][0] = -1.0;  verts[3][1] =  1.0;  verts[3][2] = zLeft;
+
+	glEnableClientState(GL_VERTEX_ARRAY);
+	glVertexPointer(3, GL_FLOAT, 0, verts);
+	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+}
+
+
+enum piglit_result
+piglit_display(void)
+{
+	const GLfloat epsilon = 2.0 / piglit_width;
+	GLfloat *buf;
+	bool pass = true;
+	int pos, i;
+
+	/* draw full-window quad with z increasing left to right */
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	glEnable(GL_DEPTH_TEST);
+	draw_z_gradient(-1.0, 1.0);
+
+	buf = (GLfloat *) malloc(piglit_width * sizeof(GLfloat));
+
+	glReadPixels(0, piglit_height / 2, piglit_width, 1,
+		     GL_DEPTH_COMPONENT, GL_FLOAT, buf);
+
+	pos = 0;
+	if (fabs(buf[pos] - 0.0) > epsilon) {
+		printf("Left-most Z value should be close to 0.0, found %f\n",
+		       buf[pos]);
+		pass = false;
+	}
+
+	pos = piglit_width / 2;
+	if (fabs(buf[pos] - 0.5) > epsilon) {
+		printf("Middle Z value should be close to 0.5, found %f\n",
+		       buf[pos]);
+		pass = false;
+	}
+
+	pos = piglit_width - 1;
+	if (fabs(buf[pos] - 1.0) > epsilon) {
+		printf("Left-most Z value should be close to 1.0, found %f\n",
+		       buf[pos]);
+		pass = false;
+	}
+
+	/* check for monotonicity */
+	for (i = 1; i < piglit_width; i++) {
+		if (buf[i - 1] > buf[i]) {
+			printf("Z values aren't increasing from left to right. buf[%d]=%f > buf[%d]=%f\n",
+			       i-1, buf[i-1], i, buf[i]);
+			pass = false;
+			break;
+		}
+	}
+
+	free(buf);
+
+	piglit_present_results();
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
+
+
+void
+piglit_init(int argc, char **argv)
+{
+}
-- 
1.7.3.4