arb_shader_image_load_store: Import dead fragments test.

Test that image stores and atomics have no effect when called from
fragment shader invocations that aren't covered by a primitive or have
been discarded.

3 files changed, 251 insertions, 0 deletions

diff --git a/tests/all.py b/tests/all.py
index e4bdc1786..a21ff5eb0 100644
--- a/tests/all.py
+++ b/tests/all.py
@@ -4429,6 +4429,7 @@ import_glsl_parser_tests(spec['ARB_shader_image_load_store'],
 arb_shader_image_load_store['atomicity'] = PiglitGLTest(['arb_shader_image_load_store-atomicity'], run_concurrent=True)
 arb_shader_image_load_store['bitcast'] = PiglitGLTest(['arb_shader_image_load_store-bitcast'], run_concurrent=True)
 arb_shader_image_load_store['coherency'] = PiglitGLTest(['arb_shader_image_load_store-coherency'], run_concurrent=True)
+arb_shader_image_load_store['dead-fragments'] = PiglitGLTest(['arb_shader_image_load_store-dead-fragments'], run_concurrent=True)
 
 profile.tests['hiz'] = hiz
 profile.tests['fast_color_clear'] = fast_color_clear
diff --git a/tests/spec/arb_shader_image_load_store/CMakeLists.gl.txt b/tests/spec/arb_shader_image_load_store/CMakeLists.gl.txt
index 6a6aa25d9..af8d85b5d 100644
--- a/tests/spec/arb_shader_image_load_store/CMakeLists.gl.txt
+++ b/tests/spec/arb_shader_image_load_store/CMakeLists.gl.txt
@@ -15,5 +15,6 @@ set(depends image.c grid.c common.c)
 piglit_add_executable(arb_shader_image_load_store-atomicity atomicity.c ${depends})
 piglit_add_executable(arb_shader_image_load_store-bitcast bitcast.c ${depends})
 piglit_add_executable(arb_shader_image_load_store-coherency coherency.c ${depends})
+piglit_add_executable(arb_shader_image_load_store-dead-fragments dead-fragments.c ${depends})
 
 # vim: ft=cmake:
diff --git a/tests/spec/arb_shader_image_load_store/dead-fragments.c b/tests/spec/arb_shader_image_load_store/dead-fragments.c
new file mode 100644
index 000000000..d33fa02b9
--- /dev/null
+++ b/tests/spec/arb_shader_image_load_store/dead-fragments.c
@@ -0,0 +1,249 @@
+/*
+ * Copyright (C) 2014 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 dead-fragments.c
+ *
+ * Quoting the ARB_shader_image_load_store extension:
+ * "If a fragment shader is invoked to process fragments or samples
+ *  not covered by a primitive being rasterized to facilitate the
+ *  approximation of derivatives for texture lookups, stores and
+ *  atomics have no effect."
+ *
+ * The purpose of this test is to check this assertion, as well as
+ * that image stores and atomics have no effect after a fragment is
+ * discarded.  Both tests are repeated for a few different built-in
+ * functions.
+ */
+
+#include "common.h"
+
+/** Window width. */
+#define W 16
+
+/** Window height. */
+#define H 96
+
+/** Total number of pixels in the window and image. */
+#define N (W * H)
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+config.supports_gl_core_version = 32;
+
+config.window_width = W;
+config.window_height = H;
+config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+struct image_op_info {
+        /** Image built-in name. */
+        const char *name;
+
+        /** GLSL statement that invokes this image built-in. */
+        const char *hunk;
+};
+
+static const struct image_op_info image_ops[] = {
+        {
+                "imageStore",
+                "void inc(ivec2 idx) {\n"
+                "        imageStore(img, IMAGE_ADDR(idx),"
+                "                imageLoad(img, IMAGE_ADDR(idx)) + BASE_T(1));\n"
+                "}\n"
+        },
+        {
+                "imageAtomicAdd",
+                "void inc(ivec2 idx) {\n"
+                "        imageAtomicAdd(img, IMAGE_ADDR(idx), BASE_T(1));\n"
+                "}\n"
+        },
+        {
+                "imageAtomicMax",
+                "void inc(ivec2 idx) {\n"
+                "        imageAtomicMax(img, IMAGE_ADDR(idx),"
+                "                imageLoad(img, IMAGE_ADDR(idx)).x + BASE_T(1));\n"
+                "}\n"
+        },
+        {
+                "imageAtomicExchange",
+                "void inc(ivec2 idx) {\n"
+                "        imageAtomicExchange(img, IMAGE_ADDR(idx),"
+                "                imageLoad(img, IMAGE_ADDR(idx)).x + BASE_T(1));\n"
+                "}\n"
+        },
+        {
+                "imageAtomicCompSwap",
+                "void inc(ivec2 idx) {\n"
+                "        imageAtomicCompSwap(img, IMAGE_ADDR(idx),"
+                "                imageLoad(img, IMAGE_ADDR(idx)).x,"
+                "                imageLoad(img, IMAGE_ADDR(idx)).x + BASE_T(1));\n"
+                "}\n"
+        },
+        { 0 }
+};
+
+static bool
+init_image(const struct image_info img)
+{
+        uint32_t pixels[N];
+        int i;
+
+        for (i = 0; i < N; ++i)
+                pixels[i] = i / W;
+
+        return upload_image(img, 0, pixels);
+}
+
+static bool
+check_discard(const struct grid_info grid, const struct image_info img,
+              unsigned w, unsigned h)
+{
+        uint32_t pixels[H][W], expect[H][W];
+        int i, j;
+
+        for (i = 0; i < W; ++i)
+                for (j = 0; j < H; ++j)
+                        expect[j][i] = (i % 5 == 0 ? 0 : 1) + j;
+
+        return download_image(img, 0, pixels[0]) &&
+                check_pixels_v(img, pixels[0], expect[0]);
+}
+
+static bool
+check_derivative(const struct grid_info grid, const struct image_info img,
+                 unsigned w, unsigned h)
+{
+        uint32_t pixels_fb[H][W], expect_fb[H][W];
+        uint32_t pixels_img[H][W], expect_img[H][W];
+        int i, j;
+
+        for (i = 0; i < W; ++i) {
+                for (j = 0; j < H; ++j) {
+                        expect_fb[j][i] = (j < h && i < w ? 1000 :
+                                           encode(get_image_format(GL_R32F), 0.5));
+                        expect_img[j][i] = (j < h && i < w ? 1 : 0) + j;
+                }
+        }
+
+        if (!download_result(grid, pixels_fb[0]) ||
+            !download_image(img, 0, pixels_img[0]))
+                return false;
+
+        if (!check_pixels_v(img, pixels_fb[0], expect_fb[0])) {
+                printf("  Source: framebuffer\n");
+                /*
+                 * Purely informational check, we don't care what the
+                 * result is as long as derivatives are being
+                 * calculated, don't fail if the result doesn't equal
+                 * the expected value as it's most likely an accuracy
+                 * issue.
+                 */
+        }
+
+        if (!check_pixels_v(img, pixels_img[0], expect_img[0])) {
+                printf("  Source: image\n");
+                return false;
+        }
+
+        return true;
+}
+
+static bool
+run_test(const struct image_op_info *op,
+         unsigned w, unsigned h,
+         bool (*check)(const struct grid_info grid,
+                       const struct image_info img,
+                       unsigned w, unsigned h),
+         const char *body)
+{
+        const struct grid_info grid =
+                grid_info(GL_FRAGMENT_SHADER, GL_R32UI, W, H);
+        const struct image_info img = image_info_for_grid(grid);
+        GLuint prog = generate_program(
+                grid, GL_FRAGMENT_SHADER,
+                concat(image_hunk(img, ""),
+                       hunk("uniform IMAGE_T img;\n"),
+                       hunk(op->hunk),
+                       hunk(body), NULL));
+        bool ret = prog &&
+                init_fb(grid) &&
+                init_image(img) &&
+                set_uniform_int(prog, "img", 0) &&
+                draw_grid(set_grid_size(grid, w, h), prog) &&
+                check(grid, img, w, h);
+
+        glDeleteProgram(prog);
+        return ret;
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+        enum piglit_result status = PIGLIT_PASS;
+        const struct image_op_info *op;
+
+        piglit_require_extension("GL_ARB_shader_image_load_store");
+
+        for (op = image_ops; op->name; ++op) {
+                /*
+                 * Draw a rectangle discarding a subset of the
+                 * fragments before inc() is run, then make sure that
+                 * it had no effect for those fragments.
+                 */
+                subtest(&status, true,
+                        run_test(op, W, H, check_discard,
+                                 "GRID_T op(ivec2 idx, GRID_T x) {\n"
+                                 "        if (idx.x % 5 == 0)\n"
+                                 "                discard;\n"
+                                 "        inc(idx);\n"
+                                 "        return x;\n"
+                                 "}\n"),
+                        "%s/discard test", op->name);
+
+                /*
+                 * Draw a 1-pixel wide rectangle and make a derivative
+                 * computation in the orthogonal direction to get the
+                 * GPU to run fragment shader invocations located
+                 * outside the primitive, then make sure that inc()
+                 * had no effect for those fragments.
+                 */
+                subtest(&status, true,
+                        run_test(op, W - 3, 1, check_derivative,
+                                 "GRID_T op(ivec2 idx, GRID_T x) {\n"
+                                 "        x = uvec4(1000 * dFdy(vec4("
+                                 "                imageLoad(img, IMAGE_ADDR(idx)))));"
+                                 "        inc(idx);\n"
+                                 "        return x;\n"
+                                 "}\n"),
+                        "%s/derivative test", op->name);
+        }
+
+        piglit_report_result(status);
+}
+
+enum piglit_result
+piglit_display(void)
+{
+        return PIGLIT_FAIL;
+}