[Piglit] [PATCH] Test that dFdx/dFdy work properly on fbos
Paul Berry
stereotype441 at gmail.com
Wed Jun 20 15:16:53 PDT 2012
This test exposes a bug in Mesa on i965 hardware (as of commit
f2f05e5): the GLSL function dFdy() produces incorrect results when
rendering to an FBO. This is a consequence of the fact that FBOs
place the origin at the upper left, whereas windowsystem framebuffers
place the origin at the lower left.
Verified using nVidia's proprietary binary driver for Linux.
---
tests/all.tests | 1 +
tests/fbo/CMakeLists.gl.txt | 1 +
tests/fbo/fbo-deriv.c | 150 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 152 insertions(+), 0 deletions(-)
create mode 100644 tests/fbo/fbo-deriv.c
diff --git a/tests/all.tests b/tests/all.tests
index 76bf001..bf081d9 100644
--- a/tests/all.tests
+++ b/tests/all.tests
@@ -203,6 +203,7 @@ add_plain_test(fbo, 'fbo-copyteximage-simple')
add_plain_test(fbo, 'fbo-depth-array')
add_plain_test(fbo, 'fbo-depthtex')
add_plain_test(fbo, 'fbo-depth-sample-compare')
+add_plain_test(fbo, 'fbo-deriv')
add_plain_test(fbo, 'fbo-drawbuffers')
add_plain_test(fbo, 'fbo-drawbuffers-arbfp')
add_plain_test(fbo, 'fbo-drawbuffers-blend-add')
diff --git a/tests/fbo/CMakeLists.gl.txt b/tests/fbo/CMakeLists.gl.txt
index 7025019..7e15ae2 100644
--- a/tests/fbo/CMakeLists.gl.txt
+++ b/tests/fbo/CMakeLists.gl.txt
@@ -37,6 +37,7 @@ piglit_add_executable (fbo-copypix fbo-copypix.c)
piglit_add_executable (fbo-readdrawpix fbo-readdrawpix.c)
piglit_add_executable (fbo-clearmipmap fbo-clearmipmap.c)
piglit_add_executable (fbo-clear-formats fbo-clear-formats.c)
+piglit_add_executable (fbo-deriv fbo-deriv.c)
piglit_add_executable (fbo-drawbuffers fbo-drawbuffers.c)
piglit_add_executable (fbo-drawbuffers-arbfp fbo-drawbuffers-arbfp.c)
piglit_add_executable (fbo-drawbuffers-blend-add fbo-drawbuffers-blend-add.c)
diff --git a/tests/fbo/fbo-deriv.c b/tests/fbo/fbo-deriv.c
new file mode 100644
index 0000000..56779c6
--- /dev/null
+++ b/tests/fbo/fbo-deriv.c
@@ -0,0 +1,150 @@
+/*
+ * 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.
+ */
+
+/**
+ * \file fbo-deriv.cp
+ *
+ * Verify that the implementation produces correct values for the GLSL
+ * dFdx() and dFdy() functions, both in fbos and in the default
+ * framebuffer.
+ *
+ * Note: the reason that we test both fbos and the default framebuffer
+ * in the same test is that some implementations (e.g. Mesa/i965) need
+ * to compile the dFdy() function differently depending whether we are
+ * rendering to an FBO or to the default framebuffer; testing both in
+ * the same test allows us to verify that the implementation
+ * recompiles the shader if necessary.
+ *
+ * This test draws a pair of squares in which dFdx and dFdy are
+ * expected to both be 1.0. It colors the rectangles red=0.5*dFdx and
+ * green=0.5*dFdy, so the expected color is (0.5, 0.5, 0, 0). The
+ * left rectangle is drawn in the default framebuffer; the right
+ * rectangle is drawn in an FBO and then blitted to the default
+ * framebuffer.
+ */
+
+#include "piglit-util.h"
+
+int piglit_width = 256, piglit_height = 128;
+int piglit_window_mode = GLUT_DOUBLE | GLUT_RGBA;
+static const int fbo_width = 128, fbo_height = 128;
+
+static GLuint fbo;
+static GLint prog;
+
+static const char *vert =
+ "void main()\n"
+ "{\n"
+ " gl_Position = gl_Vertex;\n"
+ "}\n";
+
+static const char *frag =
+ "void main()\n"
+ "{\n"
+ " gl_FragColor = vec4(0.5*dFdx(gl_FragCoord.x),\n"
+ " 0.5*dFdy(gl_FragCoord.y), 0.0, 0.0);\n"
+ "}\n";
+
+static void
+create_fbo()
+{
+ GLenum status;
+ GLuint rb;
+
+ glGenRenderbuffers(1, &rb);
+ glBindRenderbuffer(GL_RENDERBUFFER, rb);
+ glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA, fbo_width, fbo_height);
+ glGenFramebuffers(1, &fbo);
+ glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo);
+ glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+ GL_RENDERBUFFER, rb);
+ status = glCheckFramebufferStatusEXT (GL_FRAMEBUFFER_EXT);
+
+ if (!piglit_check_gl_error(GL_NO_ERROR))
+ piglit_report_result(PIGLIT_FAIL);
+
+ switch (status) {
+ case GL_FRAMEBUFFER_UNSUPPORTED:
+ printf("Framebuffer unsupported\n");
+ piglit_report_result(PIGLIT_SKIP);
+ break;
+ case GL_FRAMEBUFFER_COMPLETE:
+ break;
+ default:
+ printf("Framebuffer incomplete\n");
+ piglit_report_result(PIGLIT_FAIL);
+ break;
+ }
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+ GLint vs, fs;
+
+ if (piglit_get_gl_version() < 20) {
+ printf("Requires OpenGL 2.0\n");
+ piglit_report_result(PIGLIT_SKIP);
+ }
+
+ vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vert);
+ fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, frag);
+ prog = piglit_link_simple_program(vs, fs);
+
+ create_fbo();
+}
+
+enum piglit_result
+piglit_display(void)
+{
+ float expected[3] = { 0.5, 0.5, 0.0 };
+ GLboolean pass = GL_TRUE;
+
+ glUseProgram(prog);
+
+ /* Draw a square to the left half of the window */
+ glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+ glViewport(0, 0, piglit_width, piglit_height);
+ piglit_draw_rect(-1, -1, 1, 2);
+
+ /* Draw a square to the FBO */
+ glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo);
+ glViewport(0, 0, fbo_width, fbo_height);
+ piglit_draw_rect(-1, -1, 2, 2);
+
+ /* Blit the square from the FBO to the right half of the window */
+ glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
+ glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+ glBlitFramebuffer(0, 0, fbo_width, fbo_height,
+ piglit_width/2, 0, piglit_width, piglit_height,
+ GL_COLOR_BUFFER_BIT, GL_NEAREST);
+
+ /* Check that both squares have the correct color */
+ glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
+ pass = piglit_probe_rect_rgb(0, 0, piglit_width, piglit_height,
+ expected) && pass;
+
+ piglit_present_results();
+
+ return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
--
1.7.7.6
More information about the Piglit
mailing list