path: root/src/library_gl.js

/*
 * GL support. See https://github.com/kripken/emscripten/wiki/OpenGL-support
 * for current status.
 */

var LibraryGL = {
  $GL: {
    counter: 1,
    buffers: {},
    programs: {},
    framebuffers: {},
    renderbuffer: {},
    textures: {},
    uniforms: {},
    shaders: {},

    // Linear lookup in one of the tables (buffers, programs, etc.). TODO: consider using a weakmap to make this faster, if it matters
    scan: function(table, object) {
      for (var item in table) {
        if (table[item] == object) return item;
      }
      return 0;
    },

    // Find a token in a shader source string
    findToken: function(source, token) {
      function isIdentChar(ch) {
        if (ch >= 48 && ch <= 57) // 0-9
          return true;
        if (ch >= 65 && ch <= 90) // A-Z
          return true;
        if (ch >= 97 && ch <= 122) // a-z
          return true;
        return false;
      }
      var i = -1;
      do {
        i = source.indexOf(token, i + 1);
        if (i < 0) {
          break;
        }
        if (i > 0 && isIdentChar(source[i - 1])) {
          continue;
        }
        i += token.length;
        if (i < source.length - 1 && isIdentChar(source[i + 1])) {
          continue;
        }
        return true;
      } while (true);
      return false;
    }
  },

  glGetString: function(name_) {
    switch(name_) {
      case 0x1F00 /* GL_VENDOR */:
      case 0x1F01 /* GL_RENDERER */:
      case 0x1F02 /* GL_VERSION */:
        return allocate(intArrayFromString(Module.ctx.getParameter(name_)), 'i8', ALLOC_NORMAL);
      case 0x1F03 /* GL_EXTENSIONS */:
        return allocate(intArrayFromString(Module.ctx.getSupportedExtensions().join(' ')), 'i8', ALLOC_NORMAL);
      default:
        throw 'Failure: Invalid glGetString value: ' + name_;
    }
  },

  glGetIntegerv: function(name_, p) {
    var result = Module.ctx.getParameter(name_);
    switch (typeof(result)) {
      case "number":
        {{{ makeSetValue('p', '0', 'result', 'i32') }}};
        break;
      case "boolean":
        {{{ makeSetValue('p', '0', 'result ? 1 : 0', 'i8') }}};
        break;
      case "string":
        throw 'Native code calling glGetIntegerv(' + name_ + ') on a name which returns a string!';
      case "object":
        if (result === null) {
          {{{ makeSetValue('p', '0', '0', 'i32') }}};
        } else if (result instanceof Float32Array ||
                   result instanceof Uint32Array ||
                   result instanceof Int32Array ||
                   result instanceof Array) {
          for (var i = 0; i < result.length; ++i) {
            {{{ makeSetValue('p', 'i*4', 'result[i]', 'i32') }}};
          }
        } else if (result instanceof WebGLBuffer) {
          {{{ makeSetValue('p', '0', 'GL.scan(GL.buffers, result)', 'i32') }}};
        } else if (result instanceof WebGLProgram) {
          {{{ makeSetValue('p', '0', 'GL.scan(GL.programs, result)', 'i32') }}};
        } else if (result instanceof WebGLFramebuffer) {
          {{{ makeSetValue('p', '0', 'GL.scan(GL.framebuffers, result)', 'i32') }}};
        } else if (result instanceof WebGLRenderbuffer) {
          {{{ makeSetValue('p', '0', 'GL.scan(GL.renderbuffers, result)', 'i32') }}};
        } else if (result instanceof WebGLTexture) {
          {{{ makeSetValue('p', '0', 'GL.scan(GL.textures, result)', 'i32') }}};
        } else {
          throw 'Unknown object returned from WebGL getParameter';
        }
        break;
      case "undefined":
        throw 'Native code calling glGetIntegerv(' + name_ + ') and it returns undefined';
      default:
        throw 'Why did we hit the default case?';
    }
  },

  glGetFloatv: function(name_, p) {
    var result = Module.ctx.getParameter(name_);
    switch (typeof(result)) {
      case "number":
        {{{ makeSetValue('p', '0', 'result', 'float') }}};
        break;
      case "boolean":
        {{{ makeSetValue('p', '0', 'result ? 1.0 : 0.0', 'float') }}};
        break;
      case "string":
          {{{ makeSetValue('p', '0', '0', 'float') }}};
      case "object":
        if (result === null) {
          throw 'Native code calling glGetFloatv(' + name_ + ') and it returns null';
        } else if (result instanceof Float32Array ||
                   result instanceof