[Piglit] [PATCH] fbo-tex-rgbx: test rendering to and texturing from an RGBx texture

Brian Paul brianp at vmware.com
Thu Mar 20 09:14:51 PDT 2014


GL_RGB internal formats are usually stored as RGBx.  This test makes
sure that the empty alpha channel is one when we sample from the texture.
---
 tests/all.py                |    1 +
 tests/fbo/CMakeLists.gl.txt |    1 +
 tests/fbo/fbo-tex-rgbx.c    |  197 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 199 insertions(+)
 create mode 100644 tests/fbo/fbo-tex-rgbx.c

diff --git a/tests/all.py b/tests/all.py
index 6ce459d..e15cbe9 100644
--- a/tests/all.py
+++ b/tests/all.py
@@ -1673,6 +1673,7 @@ arb_framebuffer_object['FBO blit to missing attachment'] = concurrent_test('fbo-
 arb_framebuffer_object['FBO blit from missing attachment'] = concurrent_test('fbo-missing-attachment-blit from')
 arb_framebuffer_object['fbo-scissor-blit fbo'] = concurrent_test('fbo-scissor-blit fbo')
 arb_framebuffer_object['fbo-scissor-blit window'] = plain_test('fbo-scissor-blit window')
+arb_framebuffer_object['fbo-tex-rgbx'] = concurrent_test('fbo-tex-rgbx')
 arb_framebuffer_object['negative-readpixels-no-rb'] = concurrent_test('arb_framebuffer_object-negative-readpixels-no-rb')
 add_concurrent_test(arb_framebuffer_object, 'fbo-drawbuffers-none glClear')
 add_concurrent_test(arb_framebuffer_object, 'fbo-drawbuffers-none glClearBuffer')
diff --git a/tests/fbo/CMakeLists.gl.txt b/tests/fbo/CMakeLists.gl.txt
index 588fe26..2b148ae 100644
--- a/tests/fbo/CMakeLists.gl.txt
+++ b/tests/fbo/CMakeLists.gl.txt
@@ -90,6 +90,7 @@ piglit_add_executable (fbo-storage-formats fbo-storage-formats.c)
 piglit_add_executable (fbo-storage-completeness fbo-storage-completeness.c)
 piglit_add_executable (fbo-sys-blit fbo-sys-blit.c)
 piglit_add_executable (fbo-sys-sub-blit fbo-sys-sub-blit.c)
+piglit_add_executable (fbo-tex-rgbx fbo-tex-rgbx.c)
 piglit_add_executable (fbo-pbo-readpixels-small fbo-pbo-readpixels-small.c)
 piglit_add_executable (fbo-copyteximage fbo-copyteximage.c)
 piglit_add_executable (fbo-copyteximage-simple fbo-copyteximage-simple.c)
diff --git a/tests/fbo/fbo-tex-rgbx.c b/tests/fbo/fbo-tex-rgbx.c
new file mode 100644
index 0000000..61b8a80
--- /dev/null
+++ b/tests/fbo/fbo-tex-rgbx.c
@@ -0,0 +1,197 @@
+/*
+ * Copyright © 2014 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.
+ */
+
+/**
+ * \file fbo-tex-rgbx.c
+ * \author Brian Paul
+ *
+ * Test texturing from an RGB texture after we've rendered some
+ * non-1 alpha values into it.  When we sample from an RGB texture,
+ * the alpha values should always be one.
+ * Many (most?) GL implementations store RGB textures as RGBx so there
+ * really is an alpha channel but it's supposed to be ignored when we
+ * sample from it.
+ */
+
+#include "piglit-util-gl-common.h"
+
+#define TEX_SIZE 256
+
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+	config.window_width = TEX_SIZE;
+	config.window_height = TEX_SIZE;
+	config.supports_gl_compat_version = 10;
+	config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE;
+PIGLIT_GL_TEST_CONFIG_END
+
+
+static const char *fragShaderText =
+	"uniform sampler2D tex; \n"
+	"void main() \n"
+	"{ \n"
+	"   gl_FragColor = texture2D(tex, gl_TexCoord[0].xy); \n"
+	"} \n";
+
+static GLuint Program;
+
+
+/* draw green quad with varying alpha values */
+static void
+draw_quad(void)
+{
+	static const float verts[4][2] = {
+		{ -1.0f, -1.0f },
+		{  1.0f, -1.0f },
+		{  1.0f,  1.0f },
+		{ -1.0f,  1.0f }
+	};
+	static const float colors[4][4] = {
+		{ 0.0f, 1.0f, 0.0f, 0.1f },
+		{ 0.0f, 1.0f, 0.0f, 0.2f },
+		{ 0.0f, 1.0f, 0.0f, 0.8f },
+		{ 0.0f, 1.0f, 0.0f, 0.9f }
+	};
+	glVertexPointer(2, GL_FLOAT, 0, verts);
+	glColorPointer(4, GL_FLOAT, 0, colors);
+	glEnableClientState(GL_VERTEX_ARRAY);
+	glEnableClientState(GL_COLOR_ARRAY);
+	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+	glDisableClientState(GL_VERTEX_ARRAY);
+	glDisableClientState(GL_COLOR_ARRAY);
+}
+
+
+/**
+ * Create texture with given internal format.  Render to it.  Then draw
+ * a test quad using that texture.  Check that all alpha values are one.
+ */
+static bool
+test_format(GLenum internalFormat)
+{
+	GLuint tex, fbo;
+	GLenum status;
+	bool pass = true;
+	GLubyte *results;
+	GLuint i;
+
+	/* Create (RGB) tex and FBO to render into it */
+	glGenTextures(1, &tex);
+	glBindTexture(GL_TEXTURE_2D, tex);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+	glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, TEX_SIZE, TEX_SIZE, 0,
+		     GL_RGB, GL_UNSIGNED_BYTE, NULL);
+
+	glGenFramebuffers(1, &fbo);
+	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+	glFramebufferTexture2D(GL_FRAMEBUFFER,
+			       GL_COLOR_ATTACHMENT0,
+			       GL_TEXTURE_2D, tex, 0);
+	if (!piglit_check_gl_error(GL_NO_ERROR))
+		return false;
+
+	status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
+	if (status != GL_FRAMEBUFFER_COMPLETE) {
+		fprintf(stderr, "incomplete fbo (status 0x%x)\n", status);
+		return true; /* this isn't necessarily a failure */
+	}
+
+	/* Draw into tex, constant green and varying alpha */
+	glUseProgram(0);
+	draw_quad();
+
+	/* Now draw a textured quad in the window using the texture that we
+	 * just rendered to.
+	 */
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+	glUseProgram(Program);
+
+	piglit_draw_rect_tex(-1.0f, -1.0f, 2.0f, 2.0f,
+			     0.0f, 0.0f, 1.0f, 1.0f);
+
+	/* Now read back the rendering and check that alpha is always one */
+	results = malloc(TEX_SIZE * TEX_SIZE * 4);
+	glReadPixels(0, 0, TEX_SIZE, TEX_SIZE,
+		     GL_RGBA, GL_UNSIGNED_BYTE, results);
+
+	for (i = 0; i < TEX_SIZE * TEX_SIZE; i++) {
+		if (results[i*4+3] != 255) {
+			fprintf(stderr,
+				"Bad alpha value at texel [%d]: %d."
+				"  Should be 255."
+				"  Texture format %s\n",
+				i, results[i*4+3],
+				piglit_get_gl_enum_name(internalFormat));
+			pass = false;
+			break;
+		}
+	}
+
+	free(results);
+
+	piglit_present_results();
+
+	glDeleteFramebuffers(1, &fbo);
+	glDeleteTextures(1, &tex);
+
+	return pass;
+}
+
+
+void
+piglit_init(int argc, char **argv)
+{
+	piglit_require_extension("GL_ARB_framebuffer_object");
+	piglit_require_gl_version(20);
+
+	Program = piglit_build_simple_program(NULL, fragShaderText);
+	assert(Program);
+}
+
+
+enum piglit_result
+piglit_display(void)
+{
+	bool pass = true;
+
+	pass = test_format(GL_RGB) && pass;
+	pass = test_format(GL_RGB4) && pass;
+	pass = test_format(GL_RGB5) && pass;
+	pass = test_format(GL_RGB8) && pass;
+	pass = test_format(GL_RGB10) && pass;
+	pass = test_format(GL_RGB12) && pass;
+	pass = test_format(GL_RGB16) && pass;
+
+	if (piglit_is_extension_supported("GL_ARB_ES2_compatibility")) {
+		pass = test_format(GL_RGB565) && pass;
+	}
+
+	if (piglit_is_extension_supported("GL_EXT_texture_sRGB")) {
+		pass = test_format(GL_SRGB) && pass;
+		pass = test_format(GL_SRGB8) && pass;
+	}
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
-- 
1.7.10.4



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