diff options
| -rw-r--r-- | src/library_gl.js | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/src/library_gl.js b/src/library_gl.js index d99d59ec..1bb94253 100644 --- a/src/library_gl.js +++ b/src/library_gl.js @@ -24,6 +24,31 @@ var LibraryGL = { } 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 = source.indexOf(token); + if (i < 0) { + return false; + } + if (i > 0 && isIdentChar(source[i - 1])) { + return false; + } + i += token.length; + if (i < source.length - 1 && isIdentChar(source[i + 1])) { + return false; + } + return true; + }, }, glGetString: function(name_) { @@ -529,6 +554,21 @@ var LibraryGL = { } source += frag; } + // Let's see if we need to enable the standard derivatives extension + type = Module.ctx.getShaderParameter(GL.shaders[shader], 0x8B4F /* GL_SHADER_TYPE */); + if (type == 0x8B30 /* GL_FRAGMENT_SHADER */) { + if (GL.findToken(source, "dFdx") || + GL.findToken(source, "dFdy") || + GL.findToken(source, "fwidth")) { + source = "#extension GL_OES_standard_derivatives : enable\n" + source; + var extension = Module.ctx.getExtension("OES_standard_derivatives"); +#if GL_DEBUG + if (!extension) { + Module.printErr("Shader attempts to use the standard derivatives extension which is not available."); + } +#endif + } + } Module.ctx.shaderSource(GL.shaders[shader], source); }, |