| /* |
| * Copyright 2020 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 <stdio.h> |
| #include <stdlib.h> |
| #include <assert.h> |
| #include <emscripten/emscripten.h> |
| #include <emscripten/html5.h> |
| |
| #include <webgl/webgl2_ext.h> |
| |
| #include <GLES3/gl3.h> |
| |
| GLuint compile_shader(GLenum shaderType, const char *src) |
| { |
| GLuint shader = glCreateShader(shaderType); |
| glShaderSource(shader, 1, &src, NULL); |
| glCompileShader(shader); |
| |
| GLint isCompiled = 0; |
| glGetShaderiv(shader, GL_COMPILE_STATUS, &isCompiled); |
| if (!isCompiled) |
| { |
| GLint maxLength = 0; |
| glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &maxLength); |
| char *buf = (char*)malloc(maxLength); |
| glGetShaderInfoLog(shader, maxLength, NULL, buf); |
| printf("%s\n", buf); |
| free(buf); |
| return 0; |
| } |
| |
| 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; |
| } |
| |
| #ifndef WEBGL_CONTEXT_VERSION |
| #define WEBGL_CONTEXT_VERSION 2 |
| #endif |
| |
| int main() |
| { |
| EMSCRIPTEN_WEBGL_CONTEXT_HANDLE ctx; |
| EMSCRIPTEN_RESULT res; |
| EmscriptenWebGLContextAttributes attrs; |
| emscripten_webgl_init_context_attributes(&attrs); |
| attrs.majorVersion = WEBGL_CONTEXT_VERSION; |
| ctx = emscripten_webgl_create_context("#canvas", &attrs); |
| assert(ctx > 0); // Must have received a valid context. |
| res = emscripten_webgl_make_context_current(ctx); |
| assert(res == EMSCRIPTEN_RESULT_SUCCESS); |
| |
| #ifdef EXPLICIT_SWAP |
| attrs.explicitSwapControl = 1; |
| #endif |
| |
| GLboolean extAvailable = emscripten_webgl_enable_WEBGL_draw_instanced_base_vertex_base_instance(ctx); |
| extAvailable &= emscripten_webgl_enable_WEBGL_multi_draw_instanced_base_vertex_base_instance(ctx); |
| |
| if (!extAvailable) { |
| EM_ASM({ |
| xhr = new XMLHttpRequest(); |
| xhr.open('GET', 'http://localhost:8888/report_result?skipped:%20WEBGL_draw_instanced_base_vertex_base_instance%20is%20not%20supported!'); |
| xhr.send(); |
| setTimeout(function() { window.close() }, 2000); |
| }); |
| return 0; |
| } |
| |
| static const char vertex_shader[] = |
| "#version 300 es\n" |
| "layout(location=0) in vec4 apos;" |
| "layout(location=1) in vec4 acolor;" |
| "layout(location=2) in float icolor;" |
| "out vec4 color;" |
| "void main() {" |
| "color = acolor;" |
| "color.b = icolor;" |
| "gl_Position = apos;" |
| "}"; |
| GLuint vs = compile_shader(GL_VERTEX_SHADER, vertex_shader); |
| |
| static const char fragment_shader[] = |
| "#version 300 es\n" |
| "precision lowp float;" |
| "in vec4 color;" |
| "out vec4 o_color;" |
| "void main() {" |
| "o_color = color;" |
| "}"; |
| GLuint fs = compile_shader(GL_FRAGMENT_SHADER, fragment_shader); |
| |
| GLuint program = create_program(vs, fs); |
| glUseProgram(program); |
| |
| static const float pos_and_color[] = { |
| // x, y, r, g, b |
| -0.5f, -0.5f, 1, 1, 0, |
| 0.5f, -0.5f, 1, 0, 0, |
| -0.5f, 0.5f, 0, 1, 0, |
| 0.5f, 0.5f, 0, 0, 0, |
| -0.5f, 0.5f, 0, 1, 0, |
| 0.5f, -0.5f, 1, 0, 0 |
| }; |
| |
| // 2 -- 3 |
| // | \ | |
| // | \ | |
| // 0 -- 1 |
| static const GLushort indices[] = { |
| 0, 1, 2, |
| 2, 1, 0 |
| }; |
| |
| static const float instance_color[] = { |
| 0, 1 |
| }; |
| |
| GLuint vbo; |
| glGenBuffers(1, &vbo); |
| glBindBuffer(GL_ARRAY_BUFFER, vbo); |
| glBufferData(GL_ARRAY_BUFFER, sizeof(pos_and_color), pos_and_color, GL_STATIC_DRAW); |
| glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 20, 0); |
| glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 20, (void*)8); |
| glEnableVertexAttribArray(0); |
| glEnableVertexAttribArray(1); |
| |
| GLuint ibo; |
| glGenBuffers(1, &ibo); |
| glBindBuffer(GL_ARRAY_BUFFER, ibo); |
| glBufferData(GL_ARRAY_BUFFER, sizeof(instance_color), instance_color, GL_STATIC_DRAW); |
| glVertexAttribPointer(2, 1, GL_FLOAT, GL_FALSE, 0, 0); |
| glVertexAttribDivisor(2, 1); |
| glEnableVertexAttribArray(2); |
| |
| // use element array buffer |
| GLuint elementBuffer; |
| glGenBuffers(1, &elementBuffer); |
| glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementBuffer); |
| glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW); |
| |
| glClearColor(0.3f,0.3f,0.3f,1); |
| |
| GLint firsts[] = {0, 3}; |
| GLsizei counts[] = {3, 3}; |
| GLsizei instanceCounts[] = {1, 1}; |
| const GLvoid* const offsets[] = {(GLvoid*)0, (GLvoid*)(3 * sizeof(GLushort))}; |
| GLint baseVertices[] = {0, 1}; |
| GLuint baseInstances[] = {0, 1}; |
| GLsizei drawcount = 2; |
| |
| glClear(GL_COLOR_BUFFER_BIT); |
| |
| #if MULTI_DRAW |
| #if DRAW_ELEMENTS |
| glMultiDrawElementsInstancedBaseVertexBaseInstanceWEBGL(GL_TRIANGLES, counts, GL_UNSIGNED_SHORT, offsets, instanceCounts, baseVertices, baseInstances, drawcount); |
| #else |
| glMultiDrawArraysInstancedBaseInstanceWEBGL(GL_TRIANGLES, firsts, counts, instanceCounts, baseInstances, drawcount); |
| #endif |
| #else |
| #if DRAW_ELEMENTS |
| for (GLsizei i = 0; i < drawcount; i++) { |
| glDrawElementsInstancedBaseVertexBaseInstanceWEBGL(GL_TRIANGLES, counts[i], GL_UNSIGNED_SHORT, offsets[i], instanceCounts[i], baseVertices[i], baseInstances[i]); |
| } |
| #else |
| for (GLsizei i = 0; i < drawcount; i++) { |
| glDrawArraysInstancedBaseInstanceWEBGL(GL_TRIANGLES, firsts[i], counts[i], instanceCounts[i], baseInstances[i]); |
| } |
| #endif |
| #endif |
| |
| #ifdef EXPLICIT_SWAP |
| emscripten_webgl_commit_frame(); |
| #endif |
| |
| } |