gles-3.0: NV_read_depth extension test

v2: review feedback from Iago and Ian

Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

3 files changed, 170 insertions, 0 deletions

diff --git a/tests/all.py b/tests/all.py
index 4531b01cd..610d89f2a 100644
--- a/tests/all.py
+++ b/tests/all.py
@@ -4180,6 +4180,11 @@ with profile.group_manager(
     g(['khr_compressed_astc-miptree_gles2'], 'miptree-gles')
 
 with profile.group_manager(
+         PiglitGLTest,
+         grouptools.join('spec', 'nv_read_depth')) as g:
+    g(['read_depth_gles3'])
+
+with profile.group_manager(
         PiglitGLTest,
         grouptools.join('spec', 'oes_compressed_paletted_texture')) as g:
     g(['oes_compressed_paletted_texture-api'], 'basic API')
diff --git a/tests/spec/gles-3.0/CMakeLists.gles3.txt b/tests/spec/gles-3.0/CMakeLists.gles3.txt
index d56a43e94..864c862fd 100644
--- a/tests/spec/gles-3.0/CMakeLists.gles3.txt
+++ b/tests/spec/gles-3.0/CMakeLists.gles3.txt
@@ -6,5 +6,6 @@ piglit_add_executable (gles-3.0-drawarrays-vertexid drawarrays-vertexid.c)
 piglit_add_executable(minmax_${piglit_target_api} minmax.c)
 piglit_add_executable(oes_compressed_etc2_texture-miptree_gles3 oes_compressed_etc2_texture-miptree.c)
 piglit_add_executable(texture-immutable-levels_gles3 texture-immutable-levels.c)
+piglit_add_executable(read_depth_gles3 read-depth.c)
 
 # vim: ft=cmake:
diff --git a/tests/spec/gles-3.0/read-depth.c b/tests/spec/gles-3.0/read-depth.c
new file mode 100644
index 000000000..16df47edf
--- /dev/null
+++ b/tests/spec/gles-3.0/read-depth.c
@@ -0,0 +1,164 @@
+/*
+ * Copyright © 2015 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 read-depth.c
+ *
+ * Tests NV_read_depth implementation
+ *
+ * Test iterates over table of depth buffer formats and expected types to
+ * read values back from each format. For each format it renders a rectangle at
+ * different depth levels, reads back a pixel and verifies expected depth value.
+ */
+
+#include "piglit-util-gl.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+	config.supports_gl_es_version = 30;
+	config.window_visual = PIGLIT_GL_VISUAL_DEPTH;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+static GLint prog;
+
+const char *vs_source =
+	"attribute vec4 vertex;\n"
+	"uniform float depth;\n"
+	"void main()\n"
+	"{\n"
+	"	gl_Position = vec4(vertex.xy, depth, 1.0);\n"
+	"}\n";
+
+const char *fs_source =
+	"void main()\n"
+	"{\n"
+	"}\n";
+
+const GLenum tests[] = {
+	GL_DEPTH_COMPONENT16, GL_UNSIGNED_INT_24_8_OES,
+	GL_DEPTH_COMPONENT24, GL_UNSIGNED_INT_24_8_OES,
+	GL_DEPTH_COMPONENT32F, GL_FLOAT,
+};
+
+static bool
+equals(float a, float b)
+{
+   return fabs(a - b) < 0.00001;
+}
+
+static GLuint
+create_depth_fbo(GLenum depth_type)
+{
+	GLuint fbo, buffer;
+	GLenum status;
+
+	glGenRenderbuffers(1, &buffer);
+	glBindRenderbuffer(GL_RENDERBUFFER, buffer);
+	glRenderbufferStorage(GL_RENDERBUFFER,
+		depth_type, piglit_width, piglit_height);
+
+	glGenFramebuffers(1, &fbo);
+	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+	glFramebufferRenderbuffer(GL_FRAMEBUFFER,
+		GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, buffer);
+
+	status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
+	if (status != GL_FRAMEBUFFER_COMPLETE) {
+		fprintf(stderr, "error creating framebuffer, status 0x%x\n",
+			status);
+		return 0;
+	}
+	return fbo;
+}
+
+static bool
+read_depth(GLenum type, float expect)
+{
+	GLfloat data;
+	GLuint uint_pixel;
+	if (type == GL_FLOAT) {
+		glReadPixels(0, 0, 1, 1, GL_DEPTH_COMPONENT, type,
+			(void *) &data);
+	} else {
+		glReadPixels(0, 0, 1, 1, GL_DEPTH_COMPONENT, type,
+			(void *) &uint_pixel);
+		uint_pixel = uint_pixel >> 8;
+		data = (1.0 * ((float) uint_pixel)) / 16777215.0;
+	}
+
+	if (!piglit_check_gl_error(GL_NO_ERROR))
+		return false;
+
+	if (!equals(data, expect)) {
+		fprintf(stderr, "expected %f, got %f\n", expect, data);
+		return false;
+	}
+	return true;
+}
+
+enum piglit_result
+piglit_display(void)
+{
+	GLboolean pass = true;
+	const float step = 0.1;
+
+	glEnable(GL_DEPTH_TEST);
+	glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
+
+	/* Loop through formats listed in 'tests'. */
+	for (unsigned j = 0; j < ARRAY_SIZE(tests); j += 2) {
+
+		float expect = 0.0;
+
+		GLuint fbo = create_depth_fbo(tests[j]);
+		if (!fbo)
+			return PIGLIT_FAIL;
+
+		/* Step from -1.0 to 1.0, linear depth. Render a rectangle at
+		 * depth i, read pixel and verify expected depth value.
+		 */
+		for (float i = -1.0; !equals(i, 1.0 + step); i += step) {
+
+			glClear(GL_DEPTH_BUFFER_BIT);
+			glUniform1f(glGetUniformLocation(prog, "depth"), i);
+
+			piglit_draw_rect(-1, -1, 2, 2);
+
+			if (!(read_depth(tests[j + 1], expect)))
+				return PIGLIT_FAIL;
+
+			expect += step / 2.0;
+		}
+		glDeleteFramebuffers(1, &fbo);
+	}
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+	piglit_require_extension("GL_NV_read_depth");
+	prog = piglit_build_simple_program(vs_source, fs_source);
+	glUseProgram(prog);
+}