/// <summary>
/// Link this ShaderProgram.
/// </summary>
/// <param name="ctx">
/// A <see cref="GraphicsContext"/> used for linking this ShaderProgram.
/// </param>
/// <param name="cctx">
/// A <see cref="ShaderCompilerContext"/> that specify additional compiler parameters.
/// </param>
/// <remarks>
/// <para>
/// Generate shader program source code, compile and link it. After a successfull
/// link, obtain every information about active uniform and input variables.
/// </para>
/// <para>
/// This routine generate the source code of each attached ShaderObject instance and
/// compile it. This step is performed only if really required (tendentially every
/// shader object is already compiled).
/// </para>
/// <para>
/// After having compiled every attached shader object, it's performed the linkage between
/// shader objects. After this process the ShaderProgram instance can be bound to issue
/// rendering commands.
/// </para>
/// </remarks>
/// <exception cref="InvalidOperationException">
/// Exception thrown in the case this ShaderProgram is already linked.
/// </exception>
/// <exception cref="ShaderException">
/// Exception throw in the case this ShaderProgram is not linkable.
/// </exception>
private void Link(GraphicsContext ctx, ShaderCompilerContext cctx)
{
CheckCurrentContext(ctx);
if (cctx == null)
{
throw new ArgumentNullException("cctx");
}
// Using a deep copy of the shader compiler context, since it will be modified by this ShaderProgram
// instance and the attached ShaderObject instances
cctx = new ShaderCompilerContext(cctx);
#region Compile and Attach Shader Objects
// Be sure to take every attached shader
uint[] shadersObject = null;
int shadersCount;
Gl.GetProgram(ObjectName, Gl.ATTACHED_SHADERS, out shadersCount);
if (shadersCount > 0)
{
shadersObject = new uint[shadersCount];
Gl.GetAttachedShaders(ObjectName, out shadersCount, shadersObject);
Debug.Assert(shadersCount == shadersObject.Length);
}
foreach (ShaderObject shaderObject in _ProgramObjects)
{
// Create shader object, if necessary
if (shaderObject.Exists(ctx) == false)
{
shaderObject.Create(ctx, cctx);
}
// Do not re-attach the same shader object
if ((shadersObject != null) && Array.Exists(shadersObject, delegate(uint item) { return(item == shaderObject.ObjectName); }))
{
continue;
}
// Attach shader object
Gl.AttachShader(ObjectName, shaderObject.ObjectName);
}
#endregion
#region Transform Feedback Definition
IntPtr[] feedbackVaryingsPtrs = null;
if ((_FeedbackVaryings != null) && (_FeedbackVaryings.Count > 0))
{
sLog.Debug("Feedback varyings ({0}):", cctx.FeedbackVaryingsFormat);
sLog.Indent();
foreach (string feedbackVarying in _FeedbackVaryings)
{
sLog.Debug("- {0}", feedbackVarying);
}
sLog.Unindent();
if (ctx.Caps.GlExtensions.TransformFeedback2_ARB || ctx.Caps.GlExtensions.TransformFeedback_EXT)
{
string[] feedbackVaryings = _FeedbackVaryings.ToArray();
// Bug in NVIDIA drivers? Not exactly, but the NVIDIA driver hold the 'feedbackVaryings' pointer until
// glLinkProgram is executed, causing linker errors like 'duplicate varying names are not allowed' or garbaging
// part of the returned strings via glGetTransformFeedbackVarying
feedbackVaryingsPtrs = feedbackVaryings.AllocHGlobal();
// Specify feedback varyings
Gl.TransformFeedbackVaryings(ObjectName, feedbackVaryingsPtrs, (int)cctx.FeedbackVaryingsFormat);
}
else if (ctx.Caps.GlExtensions.TransformFeedback2_NV)
{
// Nothing to do ATM
}
else
{
throw new InvalidOperationException("transform feedback not supported");
}
}
#endregion
#region Bind Fragment Locations
if (ctx.Caps.GlExtensions.GpuShader4_EXT)
{
// Setup fragment locations, where defined
foreach (KeyValuePair <string, int> pair in _FragLocations)
{
if (pair.Value >= 0)
{
Gl.BindFragDataLocation(ObjectName, (uint)pair.Value, pair.Key);
}
}
}
#endregion
#region Link Shader Program Objects
int lStatus;
sLog.Debug("Link shader program {0}", Identifier ?? "<Unnamed>");
// Link shader program
Gl.LinkProgram(ObjectName);
// Check for linking errors
Gl.GetProgram(ObjectName, Gl.LINK_STATUS, out lStatus);
// Release feedback varyings unmanaged memory
if (feedbackVaryingsPtrs != null)
{
feedbackVaryingsPtrs.FreeHGlobal();
}
if (lStatus != Gl.TRUE)
{
const int MaxInfoLength = 4096;
StringBuilder logInfo = new StringBuilder(MaxInfoLength);
int logLength;
// Obtain compilation log
Gl.GetProgramInfoLog(ObjectName, MaxInfoLength, out logLength, logInfo);
// Stop link process
StringBuilder sb = new StringBuilder(logInfo.Capacity);
string[] compilerLogLines = logInfo.ToString().Split(new char[] { '\n' }, StringSplitOptions.RemoveEmptyEntries);
foreach (string logLine in compilerLogLines)
{
sb.AppendLine(" $ " + logLine);
}
sLog.Error("Shader program \"{0}\" linkage failed: {1}", Identifier ?? "<Unnamed>", sb.ToString());
throw new ShaderException("shader program is not valid. Linker output for {0}: {1}\n", Identifier ?? "<Unnamed>", sb.ToString());
}
// Set linked flag
_Linked = true;
#endregion
#region Collect Active Program Uniforms
int uniformBufferSize, attributeBufferSize;
int uniformCount;
// Get active uniforms count
Gl.GetProgram(ObjectName, Gl.ACTIVE_UNIFORMS, out uniformCount);
// Get uniforms maximum length for name
Gl.GetProgram(ObjectName, Gl.ACTIVE_UNIFORM_MAX_LENGTH, out uniformBufferSize);
// Clear uniform mapping
_UniformMap.Clear();
_DefaultBlockUniformSlots = 0;
// Collect uniform information
for (uint i = 0; i < (uint)uniformCount; i++)
{
int uniformNameLength, uniformSize, uniformType;
// Mono optimize StringBuilder capacity after P/Invoke... ensure enought room
StringBuilder uNameBuilder = new StringBuilder(uniformBufferSize + 2);
uNameBuilder.EnsureCapacity(uniformBufferSize);
// Obtain active uniform informations
Gl.GetActiveUniform(ObjectName, i, uniformBufferSize, out uniformNameLength, out uniformSize, out uniformType, uNameBuilder);
string uniformName = uNameBuilder.ToString();
// Obtain active uniform location
int uLocation = Gl.GetUniformLocation(ObjectName, uniformName);
UniformBinding uniformBinding = new UniformBinding(uniformName, i, uLocation, (ShaderUniformType)uniformType);
// Map active uniform
_UniformMap[uniformName] = uniformBinding;
// Keep track of used slot
_DefaultBlockUniformSlots += GetUniformSlotCount(uniformBinding.UniformType);
}
// Log uniform location mapping
List <string> uniformNames = new List <string>(_UniformMap.Keys);
// Make uniform list invariant respect the used driver (ease log comparation)
uniformNames.Sort();
sLog.Debug("Shader program active uniforms:");
foreach (string uniformName in uniformNames)
{
sLog.Debug("\tUniform {0} (Type: {1}, Location: {2})", uniformName, _UniformMap[uniformName].UniformType, _UniformMap[uniformName].Location);
}
sLog.Debug("Shader program active uniform slots: {0}", _DefaultBlockUniformSlots);
#endregion
#region Collect Active Program Inputs
// Get active inputs count
int activeInputs;
Gl.GetProgram(ObjectName, Gl.ACTIVE_ATTRIBUTES, out activeInputs);
// Get inputs maximum length for name
Gl.GetProgram(ObjectName, Gl.ACTIVE_ATTRIBUTE_MAX_LENGTH, out attributeBufferSize);
// Clear input mapping
_AttributesMap.Clear();
// Collect input location mapping
for (uint i = 0; i < (uint)activeInputs; i++)
{
StringBuilder nameBuffer = new StringBuilder(attributeBufferSize);
int nameLength, size, type;
// Mono optimize StringBuilder capacity after P/Invoke... ensure enought room for the current loop
nameBuffer.EnsureCapacity(attributeBufferSize);
// Obtain active input informations
Gl.GetActiveAttrib(ObjectName, i, attributeBufferSize, out nameLength, out size, out type, nameBuffer);
// Obtain active input location
string name = nameBuffer.ToString();
int location = Gl.GetAttribLocation(ObjectName, name);
// Map active input
_AttributesMap[name] = new AttributeBinding((uint)location, (ShaderAttributeType)type);
}
// Log attribute mapping
List <string> attributeNames = new List <string>(_AttributesMap.Keys);
// Make attribute list invariant respect the used driver (ease log comparation)
attributeNames.Sort();
sLog.Debug("Shader program active attributes:");
foreach (string attributeName in attributeNames)
{
sLog.Debug("\tAttribute {0} (Type: {1}, Location: {2})", attributeName, _AttributesMap[attributeName].Type, _AttributesMap[attributeName].Location);
}
#endregion
#region Collect Fragment Locations
if (ctx.Caps.GlExtensions.GpuShader4_EXT)
{
// Get fragment locations, just in the case automatically assigned
foreach (string fragOutputName in new List <string>(_FragLocations.Keys))
{
_FragLocations[fragOutputName] = Gl.GetFragDataLocation(ObjectName, fragOutputName);
}
}
#endregion
#region Collect Feedback Varyings
if ((_FeedbackVaryings != null) && (_FeedbackVaryings.Count > 0))
{
if (ctx.Caps.GlExtensions.TransformFeedback2_ARB || ctx.Caps.GlExtensions.TransformFeedback_EXT)
{
// Map active feedback
int feebackVaryings, feebackVaryingsMaxLength;
Gl.GetProgram(ObjectName, Gl.TRANSFORM_FEEDBACK_VARYINGS, out feebackVaryings);
Gl.GetProgram(ObjectName, Gl.TRANSFORM_FEEDBACK_VARYING_MAX_LENGTH, out feebackVaryingsMaxLength);
for (uint i = 0; i < feebackVaryings; i++)
{
StringBuilder sb = new StringBuilder(feebackVaryingsMaxLength);
int length = 0, size = 0, type = 0;
Gl.GetTransformFeedbackVarying(ObjectName, (uint)i, feebackVaryingsMaxLength, out length, out size, out type, sb);
_FeedbacksMap.Add(sb.ToString(), new FeedbackBinding((ShaderAttributeType)type, (uint)size));
}
}
else if (ctx.Caps.GlExtensions.TransformFeedback2_NV)
{
// Activate varyings
foreach (string feedbackVaryingName in _FeedbackVaryings)
{
Gl.ActiveVaryingNV(ObjectName, feedbackVaryingName);
}
// Map active feedback
int feebackVaryings, feebackVaryingsMaxLength;
Gl.GetProgram(ObjectName, Gl.ACTIVE_VARYINGS_NV, out feebackVaryings);
Gl.GetProgram(ObjectName, Gl.ACTIVE_VARYING_MAX_LENGTH_NV, out feebackVaryingsMaxLength);
for (uint i = 0; i < feebackVaryings; i++)
{
StringBuilder sb = new StringBuilder(feebackVaryingsMaxLength * 2);
int length = 0, size = 0, type = 0;
Gl.GetActiveVaryingNV(ObjectName, (uint)i, feebackVaryingsMaxLength * 2, out length, out size, out type, sb);
_FeedbacksMap.Add(sb.ToString(), new FeedbackBinding((ShaderAttributeType)type, (uint)size));
}
// Specify feedback varyings
List <int> feedbackLocations = new List <int>();
foreach (string feedbackVaryingName in _FeedbackVaryings)
{
int location = Gl.GetVaryingLocationNV(ObjectName, feedbackVaryingName);
if (location >= 0)
{
feedbackLocations.Add(location);
}
}
Gl.TransformFeedbackVaryingsNV(ObjectName, feedbackLocations.ToArray(), (int)cctx.FeedbackVaryingsFormat);
// Map active feedback
}
Debug.Assert(_FeedbacksMap.Count > 0);
// Log feedback mapping
sLog.Debug("Shader program active feedbacks:");
foreach (string feedbackName in _FeedbacksMap.Keys)
{
sLog.Debug("\tFeedback {0} (Type: {1})", feedbackName, _FeedbacksMap[feedbackName].Type);
}
}
#endregion
}