[Piglit] [PATCH v2] fbo: add a test for blending with float special values
Ilia Mirkin
imirkin at alum.mit.edu
Sat Nov 4 22:01:28 UTC 2017
See what happens when doing 0 * Inf and NaN.
Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---
Slightly more extensive, and now comes with options for various expectations.
This still can't model i965/SKL, since its GL_ZERO behaves differently
depending on whether the destination values are loaded or not (so the logic
differs for GL_SRC_ALPHA + GL_ZERO and GL_DST_ALPHA + GL_ZERO).
tests/fbo/CMakeLists.gl.txt | 2 +
tests/fbo/fbo-float-nan.c | 184 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 186 insertions(+)
create mode 100644 tests/fbo/fbo-float-nan.c
diff --git a/tests/fbo/CMakeLists.gl.txt b/tests/fbo/CMakeLists.gl.txt
index 2e2cac9d9..2db8bf700 100644
--- a/tests/fbo/CMakeLists.gl.txt
+++ b/tests/fbo/CMakeLists.gl.txt
@@ -97,4 +97,6 @@ piglit_add_executable (fbo-cubemap fbo-cubemap.c)
piglit_add_executable (fbo-scissor-bitmap fbo-scissor-bitmap.c)
piglit_add_executable (fbo-viewport fbo-viewport.c)
+piglit_add_executable (fbo-float-nan fbo-float-nan.c)
+
# vim: ft=cmake:
diff --git a/tests/fbo/fbo-float-nan.c b/tests/fbo/fbo-float-nan.c
new file mode 100644
index 000000000..edffa2f5d
--- /dev/null
+++ b/tests/fbo/fbo-float-nan.c
@@ -0,0 +1,184 @@
+/*
+ * Copyright © 2017 Ilia Mirkin <imirkin at alum.mit.edu>
+ *
+ * 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.
+ */
+
+/*
+ * The purpose of this test is to find out what happens when the
+ * shader produces a NaN value with a floating point RT. This is all
+ * undefined as far as the GL spec goes, but it's useful to be able to
+ * compare implementations.
+ */
+
+#include "piglit-util-gl.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+ config.supports_gl_core_version = 31;
+ config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE;
+ config.khr_no_error_support = PIGLIT_NO_ERRORS;
+PIGLIT_GL_TEST_CONFIG_END
+
+static const char *vs_text =
+ "#version 130 \n"
+ "in vec4 piglit_vertex; \n"
+ "void main() { \n"
+ " gl_Position = piglit_vertex; \n"
+ "}\n";
+
+static const char *fs_text =
+ "#version 130 \n"
+ "#extension GL_ARB_shader_bit_encoding: require \n"
+ "out vec4 color; \n"
+ "uniform uint c; \n"
+ "uniform uint a; \n"
+ "void main() { \n"
+ " color = vec4(vec3(uintBitsToFloat(c)), uintBitsToFloat(a)); \n"
+ "}\n";
+
+GLuint program, fb, rb;
+
+static const unsigned uINF = 0x7f800000;
+static const unsigned uNAN = 0x7fc00000;
+
+bool is_nan(unsigned arg) {
+ return ((arg & 0x7f800000) == 0x7f800000) &&
+ (arg & 0x007fffff);
+}
+
+void test_draw(unsigned u_c, unsigned u_a, unsigned r, unsigned g, unsigned b, unsigned a)
+{
+ unsigned pixel[4];
+
+ glUniform1ui(glGetUniformLocation(program, "c"), u_c);
+ glUniform1ui(glGetUniformLocation(program, "a"), u_a);
+ piglit_draw_rect(-1, -1, 2, 2);
+ glReadPixels(0, 0, 1, 1, GL_RGBA, GL_FLOAT, pixel);
+
+ bool rmatch = pixel[0] == r || (is_nan(pixel[0]) && is_nan(r));
+ bool gmatch = pixel[1] == g || (is_nan(pixel[1]) && is_nan(g));
+ bool bmatch = pixel[2] == b || (is_nan(pixel[2]) && is_nan(b));
+ bool amatch = pixel[3] == a || (is_nan(pixel[3]) && is_nan(a));
+ if (!rmatch || !gmatch || !bmatch || !amatch)
+ printf("Unexpected result c=%x, a=%x: %x %x %x %x != %x %x %x %x\n",
+ u_c, u_a,
+ pixel[0], pixel[1], pixel[2], pixel[3],
+ r, g, b, a);
+}
+
+/* inf_x_zero: If a zero blend factor is multiplied with an infinity
+ * or nan [or vice versa], whether the resutl is nan or zero.
+ *
+ * blend_zero: If one uses a GL_ZERO factor, but the source is
+ * infinity or nan, what value does that become. i.e. does
+ * GL_ZERO always win, or should be multiplication be done
+ * per IEEE.
+ */
+void run_test(unsigned inf_x_zero, unsigned blend_zero) {
+ glBindFramebuffer(GL_FRAMEBUFFER, fb);
+ glClearColor(0, 0, 0, 0);
+
+ printf("Testing without blending.\n");
+ glDisable(GL_BLEND);
+ test_draw(0, 0, 0, 0, 0, 0);
+ test_draw(uINF, uINF, uINF, uINF, uINF, uINF);
+ test_draw(uNAN, uNAN, uNAN, uNAN, uNAN, uNAN);
+
+ printf("Testing with blending src SRC_ALPHA + dst ZERO.\n");
+ glEnable(GL_BLEND);
+ glBlendFunc(GL_SRC_ALPHA, GL_ZERO);
+ glClear(GL_COLOR_BUFFER_BIT);
+ test_draw(0, uNAN, inf_x_zero, inf_x_zero, inf_x_zero, uNAN);
+ glClear(GL_COLOR_BUFFER_BIT);
+ test_draw(uNAN, 0, inf_x_zero, inf_x_zero, inf_x_zero, 0);
+ glClear(GL_COLOR_BUFFER_BIT);
+ test_draw(0, uINF, inf_x_zero, inf_x_zero, inf_x_zero, uINF);
+ glClear(GL_COLOR_BUFFER_BIT);
+ test_draw(uINF, 0, inf_x_zero, inf_x_zero, inf_x_zero, 0);
+ glClear(GL_COLOR_BUFFER_BIT);
+ test_draw(uINF, uNAN, uNAN, uNAN, uNAN, uNAN); /* NaN * Inf = NaN */
+ glClear(GL_COLOR_BUFFER_BIT);
+ test_draw(uNAN, uINF, uNAN, uNAN, uNAN, uINF); /* NaN * Inf = NaN */
+ /* No clear. Use the DST's nan/inf values to test against GL_ZERO */
+ test_draw(0, 0, blend_zero, blend_zero, blend_zero, blend_zero);
+
+ printf("Testing with blending src DST_ALPHA + dst ZERO.\n");
+ glBlendFunc(GL_DST_ALPHA, GL_ZERO);
+ /* Zero in DST_ALPHA */
+ glClear(GL_COLOR_BUFFER_BIT);
+ test_draw(uINF, uNAN, inf_x_zero, inf_x_zero, inf_x_zero, inf_x_zero);
+ /* Get infinity into DST_ALPHA */
+ glDisable(GL_BLEND);
+ test_draw(0, uINF, 0, 0, 0, uINF);
+ glEnable(GL_BLEND);
+ test_draw(0, uINF, inf_x_zero, inf_x_zero, inf_x_zero, blend_zero ? blend_zero : uINF);
+
+ /* Get NaN into DST_ALPHA */
+ glDisable(GL_BLEND);
+ test_draw(0, uNAN, 0, 0, 0, uNAN);
+ glEnable(GL_BLEND);
+ test_draw(0, uINF, inf_x_zero, inf_x_zero, inf_x_zero, uNAN);
+}
+
+enum piglit_result piglit_display(void)
+{
+ return PIGLIT_PASS;
+}
+
+void piglit_init(int argc, char **argv)
+{
+ piglit_require_extension("GL_ARB_shader_bit_encoding");
+ program = piglit_build_simple_program(vs_text, fs_text);
+ glUseProgram(program);
+
+ glGenFramebuffers(1, &fb);
+ glBindFramebuffer(GL_FRAMEBUFFER, fb);
+
+ glGenRenderbuffers(1, &rb);
+ glBindRenderbuffer(GL_RENDERBUFFER, rb);
+
+ glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+ GL_RENDERBUFFER, rb);
+
+ unsigned zero_x_inf = 0, blend_zero = 0;
+ for (int i = 1; i < argc; i++) {
+ if (strcmp(argv[i], "-nan") == 0) {
+ zero_x_inf = uNAN;
+ } else if (strcmp(argv[i], "-blend_zero") == 0) {
+ blend_zero = uNAN;
+ }
+ }
+
+ printf("Testing GL_RGBA16F\n");
+ glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA16F, 64, 64);
+ run_test(zero_x_inf, blend_zero);
+
+ printf("Testing GL_RGBA32F\n");
+ glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA32F, 64, 64);
+ run_test(zero_x_inf, blend_zero);
+
+#if 0
+ printf("Testing GL_RGBA8. Lots of failures expected.\n");
+ glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, 64, 64);
+ run_test(0, 0);
+#endif
+
+ piglit_report_result(PIGLIT_PASS);
+}
--
2.13.6
More information about the Piglit
mailing list