| /* |
| * Copyright 2018 The Emscripten Authors. All rights reserved. |
| * Emscripten is available under two separate licenses, the MIT license and the |
| * University of Illinois/NCSA Open Source License. Both these licenses can be |
| * found in the LICENSE file. |
| */ |
| |
| #include <assert.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <emscripten/emscripten.h> |
| #include <emscripten/html5.h> |
| #include <webgl/webgl1.h> |
| #include <webgl/webgl1_ext.h> |
| #include <vector> |
| |
| #define NUM_SHADERS_TO_LINK 100 |
| |
| GLuint compile_shader(GLenum shaderType, const char *src) |
| { |
| GLuint shader = glCreateShader(shaderType); |
| glShaderSource(shader, 1, &src, NULL); |
| glCompileShader(shader); |
| |
| return shader; |
| } |
| |
| GLuint create_program(GLuint vertexShader, GLuint fragmentShader) |
| { |
| GLuint program = glCreateProgram(); |
| glAttachShader(program, vertexShader); |
| glAttachShader(program, fragmentShader); |
| glBindAttribLocation(program, 0, "apos"); |
| glBindAttribLocation(program, 1, "acolor"); |
| glLinkProgram(program); |
| return program; |
| } |
| |
| bool check_program_link_completed(GLuint program) |
| { |
| GLint completed = 0; |
| glGetProgramiv(program, GL_COMPLETION_STATUS_KHR, &completed); |
| return completed; |
| } |
| |
| double linkStart = 0; |
| int numRafFramesElapsed = 0; |
| int numShadersPending = 0; |
| std::vector<std::pair<GLuint, double> > pendingLinks; |
| |
| int parallel_shader_compile_is_working = 0; |
| |
| EM_BOOL tick(double, void*) |
| { |
| for(size_t i = 0; i < pendingLinks.size(); ++i) |
| { |
| if (pendingLinks[i].first && check_program_link_completed(pendingLinks[i].first)) |
| { |
| double elapsed = emscripten_get_now() - pendingLinks[i].second; |
| printf("Shader %d link completed in %d rAF frames/%f msecs.\n", (int)i, numRafFramesElapsed, elapsed); |
| pendingLinks[i].first = 0; |
| --numShadersPending; |
| |
| // This is how we detect that parallel shader compilation must be working: spawning NUM_SHADERS_TO_LINK shader |
| // compiles cannot all finish within a single rAF() period, so some of them must finish after the first rAF. |
| // If they all finished within the first rAF(), they must have gotten synchronously linked in main(). |
| if (numRafFramesElapsed > 0) |
| parallel_shader_compile_is_working = 1; |
| } |
| } |
| |
| if (numShadersPending == 0) |
| { |
| printf("All shaders linked in %f msecs. parallel_shader_compile_is_working=%d\n", emscripten_get_now() - linkStart, parallel_shader_compile_is_working); |
| assert(parallel_shader_compile_is_working); |
| emscripten_force_exit(0); |
| } |
| |
| ++numRafFramesElapsed; |
| return EM_TRUE; |
| } |
| |
| int main() |
| { |
| EmscriptenWebGLContextAttributes attr; |
| emscripten_webgl_init_context_attributes(&attr); |
| |
| EMSCRIPTEN_WEBGL_CONTEXT_HANDLE ctx = emscripten_webgl_create_context("#canvas", &attr); |
| emscripten_webgl_make_context_current(ctx); |
| |
| EM_BOOL supported = emscripten_webgl_enable_extension(ctx, "KHR_parallel_shader_compile"); |
| if (!supported) |
| { |
| printf("Skipping test, KHR_parallel_shader_compile WebGL extension is not supported.\n"); |
| return 0; |
| } |
| |
| linkStart = emscripten_get_now(); |
| |
| for(int i = 0; i < NUM_SHADERS_TO_LINK; ++i) |
| { |
| char shader[256]; |
| sprintf(shader, |
| "attribute vec4 apos;" |
| "attribute vec4 acolor;" |
| "varying vec4 color;" |
| "void main() {" |
| "color = acolor;" |
| "gl_Position = apos + vec4(%f,%f,%f,0.0);" |
| "}", (float)i, (float)i, (float)i); |
| |
| GLuint vs = compile_shader(GL_VERTEX_SHADER, shader); |
| |
| sprintf(shader, |
| "precision lowp float;" |
| "varying vec4 color;" |
| "void main() {" |
| "gl_FragColor = color + vec4(%f,%f,%f,0.0);" |
| "}", (float)i, (float)i, (float)i); |
| |
| GLuint fs = compile_shader(GL_FRAGMENT_SHADER, shader); |
| |
| GLuint program = create_program(vs, fs); |
| |
| pendingLinks.push_back(std::make_pair(program, emscripten_get_now())); |
| } |
| numShadersPending = pendingLinks.size(); |
| printf("Issuing %d shader links took %f msecs.\n", numShadersPending, emscripten_get_now() - linkStart); |
| |
| emscripten_request_animation_frame_loop(tick, 0); |
| } |