Function main

test/browser/webgl2_ubo_layout_binding.c:64–201

}

int main(int argc, char *argv[])
{
  EmscriptenWebGLContextAttributes attr;
  emscripten_webgl_init_context_attributes(&attr);
  attr.majorVersion = 2;
  EMSCRIPTEN_WEBGL_CONTEXT_HANDLE ctx = emscripten_webgl_create_context("#canvas", &attr);
  emscripten_webgl_make_context_current(ctx);

  GLuint vs = CompileShader(GL_VERTEX_SHADER,
    "#version 300 es\n"
    "in vec4 pos;\n"
    "void main() { gl_Position = pos; }");

  GLuint ps = CompileShader(GL_FRAGMENT_SHADER,
    "#version 300 es\n"
    "precision lowp float;\n"
    "layout(binding = 4) uniform red { vec4 unused1; float r; };\n"
    "layout(binding = 5, std140) uniform Green { float unused2; float g; } green;\n"
    "layout(std140, binding = 6) uniform Blue { vec3 unused3; float b; } blue[2];\n"
    "out vec4 outColor;\n"
    "void main() { outColor = vec4(r, green.g, blue[0].b + blue[1].b, 1.0); }");

  // The above shader compilation should preserve the std140 layout part in the uniforms, so
  // make sure that did happen. (https://github.com/emscripten-core/emscripten/issues/25828)
  assert(strstr(emscripten_webgl_get_shader_source_utf8(ps), "layout(std140) uniform Green"));
  assert(strstr(emscripten_webgl_get_shader_source_utf8(ps), "layout(std140) uniform Blue"));

  GLuint program = CreateProgram(vs, ps);
  glUseProgram(program);

  int numBlocks;
  glGetProgramiv(program, GL_ACTIVE_UNIFORM_BLOCKS, &numBlocks);
  for(int i = 0; i < numBlocks; ++i) {
    int size = -1;
    glGetActiveUniformBlockiv(program, i, GL_UNIFORM_BLOCK_DATA_SIZE, &size);
    printf("Uniform block at index %d: size: %d\n", i, size);
  }

  static const float vb[] = {
     -1.0f, -1.0f,
      1.0f, -1.0f,
     -1.0f,  1.0f,
     -1.0f,  1.0f,
      1.0f, -1.0f,
      1.0f,  1.0f,
  };

  GLuint vbo;
  glGenBuffers(1, &vbo);
  glBindBuffer(GL_ARRAY_BUFFER, vbo);
  glBufferData(GL_ARRAY_BUFFER, sizeof(vb), vb, GL_STATIC_DRAW);
  glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 8, 0);
  glEnableVertexAttribArray(0);

  struct {
    float unused1[4];
    float r;
    float unused2[3];