[Piglit] [PATCH] arb_fragment_shader_interlock: Test image load/store.
Nicolai Hähnle
nhaehnle at gmail.com
Tue Apr 25 06:30:24 UTC 2017
Hi Plamena,
On 24.04.2017 23:04, Manolova, Plamena wrote:
[snip]
> + static const char *fs_text =
> + "#version 430\n"
> + "#extension GL_ARB_fragment_shader_interlock:
> require\n"
> + "layout(sample_interlock_ordered) in;\n"
>
>
> Since the shader writes to per-pixel data, it needs to be
> pixel_interlock_ordered. Otherwise, there might be a race between
> shader invocations that affect the same pixel but disjoint sets of
> samples (i.e. along the seams between triangles).
>
>
> Actually this test cares only about the data written to image3D
> img_output which stores data on a per-sample basis (with the z
> coordinate being the sample number), so we actually want
> sample_interlock_ordered.
The last plane/slice of img_output contains the per-pixel average over
all samples.
So I'm concerned about the following scenario of two invocations
operating on different samples of the same pixel and interleaving as
follows:
Invocation 1 Invocation 2
------------ ------------
Write current-sample data
Read and average all samples
Write current-sample data
Read and average all samples
Write per-pixel data
Write per-pixel data
Invocation 1 will produce the final per-pixel data, but won't take into
account the per-sample data written by Invocation 2. This particular
issue is fixed by using any of the pixel_interlock_* modes.
Thanks,
Nicolai
>
>
>
> + "layout(rgba32f, binding = 0) uniform image3D
> img_output;\n"
> + "layout(location = 1) uniform int sample_rate;\n"
> + "smooth in vec4 col_vary;\n"
> + "out vec4 col_out;\n"
> + "void main()\n"
> + "{\n"
> + " vec4 result = vec4(0.0, 0.0, 0.0, 1.0);\n"
> + " ivec3 current_sample_coord =
> ivec3(gl_FragCoord.x, gl_FragCoord.y, gl_SampleID);\n"
> + " ivec3 result_coord =
> ivec3(gl_FragCoord.x, gl_FragCoord.y, sample_rate);\n"
> + " int i;\n"
> + " beginInvocationInterlockARB();\n"
> + " vec4 current_sample_color =
> imageLoad(img_output, current_sample_coord);\n"
> + " result.rgb += col_vary.a * col_vary.rgb
> + (1 - col_vary.a) * current_sample_color.rgb;\n"
> + " imageStore(img_output,
> current_sample_coord, result);\n"
> + "\n"
> + " for (i = 0; i < sample_rate; i++) {\n"
> + " if (i != gl_SampleID) {\n"
> + " ivec3 sample_coord =
> ivec3(gl_FragCoord.x, gl_FragCoord.y, i);\n"
> + " vec4 sample_color =
> imageLoad(img_output, sample_coord);\n"
> + " result.rgb +=
> sample_color.rgb;\n"
> + " }\n"
> + " }\n"
> + " result.rgb /= sample_rate;\n"
> + " imageStore(img_output, result_coord,
> result);\n"
> + " endInvocationInterlockARB();\n"
> + " col_out = result;\n"
> + "}\n";
> +
> + GLuint prog;
> +
> + prog = piglit_build_simple_program(vs_text, fs_text);
> + glUseProgram(prog);
> +
> + glBindAttribLocation(prog, 0, "pos_in");
> + glBindAttribLocation(prog, 1, "col_in");
> +
> + glLinkProgram(prog);
> +
> + if (!piglit_check_gl_error(GL_NO_ERROR)) {
> + piglit_report_result(PIGLIT_FAIL);
> + }
> +
> + return prog;
> +}
> +
> +static GLuint
> +make_texture_buffer(void)
> +{
> + GLuint tex;
> +
> + glGenTextures(1, &tex);
> + glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, tex);
> + glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 2,
> + GL_RGBA32F, piglit_width, piglit_height, false);
> + glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, tex);
> +
> + return tex;
> +}
> +
> +static GLuint
> +make_texture_blend(void)
> +{
> + GLuint tex;
> +
> + glGenTextures(1, &tex);
> + glActiveTexture(GL_TEXTURE0);
> + glBindTexture(GL_TEXTURE_3D, tex);
> + glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S,
> GL_CLAMP_TO_EDGE);
> + glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T,
> GL_CLAMP_TO_EDGE);
> + glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER,
> GL_LINEAR);
> + glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER,
> GL_LINEAR);
> + glBindImageTexture(0, tex, 0, GL_TRUE, 0, GL_READ_WRITE,
> GL_RGBA32F);
> +
> + return tex;
> +}
> +
> +static GLuint
> +make_vao(void)
> +{
> + static const float pos_col[18][6] = {
> + { -1.0, -1.0, 0.0, 1.0, 0.0, 0.25 },
> + { 0.0, -1.0, 0.0, 1.0, 0.0, 0.25 },
> + { 0.0, 1.0, 0.0, 1.0, 0.0, 0.25 },
> + { 0.0, 1.0, 0.0, 1.0, 0.0, 0.25 },
> + { -1.0, 1.0, 0.0, 1.0, 0.0, 0.25 },
> + { -1.0, -1.0, 0.0, 1.0, 0.0, 0.25 },
> + { -1.0, -1.0, 1.0, 0.0, 0.0, 0.25 },
> + { 1.0, -1.0, 1.0, 0.0, 0.0, 0.25 },
> + { 1.0, 1.0, 1.0, 0.0, 0.0, 0.25 },
> + { 1.0, 1.0, 1.0, 0.0, 0.0, 0.25 },
> + { -1.0, 1.0, 1.0, 0.0, 0.0, 0.25 },
> + { -1.0, -1.0, 1.0, 0.0, 0.0, 0.25 },
> + { -1.0, -1.0, 0.0, 0.0, 1.0, 0.25 },
> + { 1.0, -1.0, 0.0, 0.0, 1.0, 0.25 },
> + { 1.0, 1.0, 0.0, 0.0, 1.0, 0.25 },
> + { 1.0, 1.0, 0.0, 0.0, 1.0, 0.25 },
> + { -1.0, 1.0, 0.0, 0.0, 1.0, 0.25 },
> + { -1.0, -1.0, 0.0, 0.0, 1.0, 0.25 }
> + };
> +
> + const int stride = sizeof(pos_col[0]);
> + GLuint vbo, vao;
> +
> + glGenVertexArrays(1, &vao);
> + glBindVertexArray(vao);
> +
> + glGenBuffers(1, &vbo);
> + glBindBuffer(GL_ARRAY_BUFFER, vbo);
> + glBufferData(GL_ARRAY_BUFFER, sizeof(pos_col), pos_col,
> GL_STATIC_DRAW);
> +
> + glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, stride,
> (void *) 0);
> + glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, stride,
> + (void *)(sizeof(float) * 2));
> +
> + glEnableVertexAttribArray(0);
> + glEnableVertexAttribArray(1);
> +
> + if (!piglit_check_gl_error(GL_NO_ERROR)) {
> + piglit_report_result(PIGLIT_FAIL);
> + }
> +
> + return vao;
> +}
> +
> +void
> +piglit_init(int argc, char **argv)
> +{
> +
> piglit_require_extension("GL_ARB_fragment_shader_interlock");
> +
> + glEnable(GL_MULTISAMPLE);
> + glDisable(GL_CULL_FACE);
> + glClearColor(0.0, 0.0, 0.0, 1.0);
> +
> + prog = make_shader_program();
> + vao = make_vao();
> + tex_frame = make_texture_buffer();
> + fbo = make_fbo();
> + tex_blend = make_texture_blend();
> +}
> +
> +enum piglit_result
> +piglit_display(void)
> +{
> + int samples[4] = { 2, 4, 8, 16 };
> + bool pass = true;
> + uint i, j, k, l;
> + uint result1[4] = { 47, 35, 63, 255 };
> + uint result2[4] = { 47, 0, 63, 255 };
> +
> + glViewport(0, 0, piglit_width, piglit_height);
> +
> + for (i = 0; i < 4; i++) {
> + GLfloat *tex_data = calloc(piglit_width *
> piglit_height *
> + (samples[i] + 1) * 4, sizeof(GLfloat));
> +
> + glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA32F,
> piglit_width, piglit_height,
> + samples[i] + 1, 0, GL_RGBA, GL_FLOAT,
> tex_data);
>
>
> Iterations should be skipped when the given number of samples is not
> supported.
>
>
> +
> + glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo);
> + glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, tex_frame);
> +
> glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, samples[i],
> + GL_RGBA8, piglit_width, piglit_height,
> false);
> + glUniform1i(1, samples[i]);
> +
> + glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT |
> + GL_STENCIL_BUFFER_BIT);
> +
> + glUseProgram(prog);
> + glDrawArrays(GL_TRIANGLES, 0, 18);
> +
> + glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
> + glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
> + glDrawBuffer(GL_BACK);
> + glBlitFramebuffer(0, 0, piglit_width,
> piglit_height, 0, 0, piglit_width,
> + piglit_height, GL_COLOR_BUFFER_BIT,
> GL_NEAREST);
>
>
> Maybe add piglit_check_gl_error?
>
> Cheers,
> Nicolai
>
>
>
> + piglit_present_results();
> +
> + glGetTexImage(GL_TEXTURE_3D, 0, GL_RGBA,
> GL_FLOAT, tex_data);
> + for (j = 0; j < samples[i] + 1; j++) {
> + for (k = 0; k < piglit_height; k++) {
> + for (l = 0; l < piglit_width; l++) {
> + uint m = ((piglit_width
> * piglit_height * j) +
> + (k *
> piglit_width) + l) * 4;
> + uint r =
> fabs(tex_data[m]) * 255;
> + uint g = fabs(tex_data[m
> + 1]) * 255;
> + uint b = fabs(tex_data[m
> + 2]) * 255;
> + uint a = fabs(tex_data[m
> + 3]) * 255;
> +
> + if ((l < piglit_width /
> 2) && (r != result1[0] ||
> + g !=
> result1[1] || b != result1[2] || a != result1[3])) {
> + printf("observed
> %u %u %u %u %u %u %u\n", j, k, l, r,
> + g, b, a);
> + printf("expected
> %u %u %u %u %u %u %u\n", j, k, l,
> + result1[0],
> result1[1], result1[2], result1[3]);
> + pass = false;
> + break;
> + }
> +
> + if ((l > piglit_width /
> 2) && (r != result2[0] ||
> + g !=
> result2[1] || b != result2[2] || a != result2[3])) {
> + printf("observed
> %u %u %u %u %u %u %u\n", j, k, l, r,
> + g, b, a);
> + printf("expected
> %u %u %u %u %u %u %u\n", j, k, l,
> +
> result1[0], result1[1], result1[2], result1[3]);
> + pass = false;
> + break;
> + }
> + }
> + if (!pass)
> + break;
> + }
> + if (!pass)
> + break;
> + }
> +
> + free(tex_data);
> + pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
> + if (!pass)
> + break;
> + }
> +
> + return pass ? PIGLIT_PASS : PIGLIT_FAIL;
> +}
>
>
>
> --
> Lerne, wie die Welt wirklich ist,
> Aber vergiss niemals, wie sie sein sollte.
>
>
--
Lerne, wie die Welt wirklich ist,
Aber vergiss niemals, wie sie sein sollte.
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