Tessellation shaders (control, evaluation) support

[gouessej]

Hi

I'm gonna provide some very small patches to add the support of tessellation shaders into Ardor3D.

I have to modify those classes:
- com.ardor3d.renderer.ContextCapabilities (I just plan to add _tessellationShadersSupported, accessors and the correct copy in one of the constructors)
- com.ardor3d.scene.state.jogl.JoglShaderObjectsStateUtil (removeTessControlShader(), removeTessEvalShader(), another step in sendToGL(...))
- com.ardor3d.renderer.state.GLSLShaderObjectsState (_tessControlShader and _tessEvalShader, their names, ids, etc...)
- com.ardor3d.renderer.jogl.JoglContextCapabilities (_tessellationShaders4Supported = gl.isExtensionAvailable("GL_ARB_tessellation_shader") && _glslSupported)

Feel free to port this code to the renderer based on LWJGL and the "legacy" renderer based on JOGL 1 (it might not work as JOGL 1 does not support tessellation shaders). I will implement it only in the renderer based on JOGL 2.0.

As I'm not an expert of shaders, I will rely on you to give it a try and test it. Best regards.

[gouessej]

Ok the patch is below, it is quite trivial:
### Eclipse Workspace Patch 1.0
#P ardor3d-core
Index: src/main/java/com/ardor3d/renderer/ContextCapabilities.java
===================================================================
--- src/main/java/com/ardor3d/renderer/ContextCapabilities.java (revision 1854)
+++ src/main/java/com/ardor3d/renderer/ContextCapabilities.java (working copy)
@@ -37,6 +37,7 @@
protected boolean _glslSupported = false;
protected boolean _geometryShader4Supported = false;
protected boolean _geometryInstancingSupported = false;
+ protected boolean _tessellationShadersSupported = false;
protected int _maxGLSLVertexAttribs;

protected boolean _pbufferSupported = false;
@@ -147,6 +148,7 @@
_geometryShader4Supported = source._geometryShader4Supported;
_glslSupported = source._glslSupported;
_geometryInstancingSupported = source._geometryInstancingSupported;
+ _tessellationShadersSupported = source._tessellationShadersSupported;
_maxAnisotropic = source._maxAnisotropic;
_maxFBOColorAttachments = source._maxFBOColorAttachments;
_maxFBOSamples = source._maxFBOSamples;
@@ -325,6 +327,14 @@
}

/**
+ * @return <code>true</code> if the GLSL is supported and GL_ARB_tessellation_shader is supported by current
+ * graphics configuration
+ */
+ public boolean isTessellationShadersSupported() {
+ return _tessellationShadersSupported;
+ }
+
+ /**
* @return true if the ARB_shader_objects extension is supported by current graphics configuration.
*/
public boolean isPbufferSupported() {
Index: src/main/java/com/ardor3d/renderer/state/GLSLShaderObjectsState.java
===================================================================
--- src/main/java/com/ardor3d/renderer/state/GLSLShaderObjectsState.java (revision 1854)
+++ src/main/java/com/ardor3d/renderer/state/GLSLShaderObjectsState.java (working copy)
@@ -74,7 +74,7 @@
/** Storage for shader attribute values */
protected List<ShaderVariable> _shaderAttributes = new ArrayList<ShaderVariable>();

- protected ByteBuffer _vertShader, _fragShader, _geomShader;
+ protected ByteBuffer _vertShader, _fragShader, _geomShader, _tessControlShader, _tessEvalShader;

// XXX: The below fields are public for brevity mostly as a way to remember that this class needs revisiting.

@@ -101,6 +101,12 @@
/** OpenGL id for the attached geometry shader. */
public int _geometryShaderID = -1;

+ /** OpenGL id for the attached tessellation control shader. */
+ public int _tessellationControlShaderID = -1;
+
+ /** OpenGL id for the attached tessellation evaluation shader. */
+ public int _tessellationEvaluationShaderID = -1;
+
/** if true, we'll send our vertex attributes to the shader via vbo */
private boolean _useAttributeVBO;

@@ -113,6 +119,12 @@
/** optional name for our geometry shader, used for debugging details. */
public String _geometryShaderName;

+ /** optional name for our tessellation control shader, used for debugging details. */
+ public String _tessellationControlShaderName;
+
+ /** optional name for our tessellation evaluation shader, used for debugging details. */
+ public String _tessellationEvaluationShaderName;
+
/**
* Gets the currently loaded vertex shader.
*
@@ -140,6 +152,24 @@
return _geomShader;
}

+ /**
+ * Gets the currently loaded tessellation control shader.
+ *
+ * @return
+ */
+ public ByteBuffer getTessellationControlShader() {
+ return _tessControlShader;
+ }
+
+ /**
+ * Gets the currently loaded tessellation evaluation shader.
+ *
+ * @return
+ */
+ public ByteBuffer getTessellationEvaluationShader() {
+ return _tessEvalShader;
+ }
+
public void setVertexShader(final InputStream stream) throws IOException {
setVertexShader(stream, "");
}
@@ -167,6 +197,24 @@
_geometryShaderName = name;
}

+ public void setTessellationControlShader(final InputStream stream) throws IOException {
+ setTessellationControlShader(stream, "");
+ }
+
+ public void setTessellationControlShader(final InputStream stream, final String name) throws IOException {
+ setTessellationControlShader(load(stream));
+ _tessellationControlShaderName = name;
+ }
+
+ public void setTessellationEvaluationShader(final InputStream stream) throws IOException {
+ setTessellationEvaluationShader(stream, "");
+ }
+
+ public void setTessellationEvaluationShader(final InputStream stream, final String name) throws IOException {
+ setTessellationEvaluationShader(load(stream));
+ _tessellationEvaluationShaderName = name;
+ }
+
protected ByteBuffer load(final InputStream in) throws IOException {
DataInputStream dataStream = null;
try {
@@ -263,6 +311,52 @@
}

/**
+ * Set the contents for our tessellation control shader
+ *
+ * @param shader
+ * the shader contents.
+ */
+ public void setTessellationControlShader(final ByteBuffer shader) {
+ setTessellationControlShader(shader, "");
+ }
+
+ /**
+ * Set the contents for our tessellation control shader
+ *
+ * @param shader
+ * the shader contents.
+ * @param name
+ * a label for this shader, displayer upon shader errors.
+ */
+ public void setTessellationControlShader(final ByteBuffer shader, final String name) {
+ _tessControlShader = shader;
+ _tessellationControlShaderName = name;
+ }
+
+ /**
+ * Set the contents for our tessellation evaluation shader
+ *
+ * @param shader
+ * the shader contents.
+ */
+ public void setTessellationEvaluationShader(final ByteBuffer shader) {
+ setTessellationEvaluationShader(shader, "");
+ }
+
+ /**
+ * Set the contents for our tessellation evaluation shader
+ *
+ * @param shader
+ * the shader contents.
+ * @param name
+ * a label for this shader, displayer upon shader errors.
+ */
+ public void setTessellationEvaluationShader(final ByteBuffer shader, final String name) {
+ _tessEvalShader = shader;
+ _tessellationEvaluationShaderName = name;
+ }
+
+ /**
* Set the contents for our vertex shader
*
* @param shader
@@ -331,6 +425,52 @@
_geometryShaderName = name;
}

+ /**
+ * Set the contents for our tessellation control shader
+ *
+ * @param shader
+ * the shader contents.
+ */
+ public void setTessellationControlShader(final String shader) {
+ setTessellationControlShader(shader, "");
+ }
+
+ /**
+ * Set the contents for our tessellation control shader
+ *
+ * @param shader
+ * the shader contents.
+ * @param name
+ * a label for this shader, displayer upon shader errors.
+ */
+ public void setTessellationControlShader(final String shader, final String name) {
+ _tessControlShader = stringToByteBuffer(shader);
+ _tessellationControlShaderName = name;
+ }
+
+ /**
+ * Set the contents for our tessellation evaluation shader
+ *
+ * @param shader
+ * the shader contents.
+ */
+ public void setTessellationEvaluationShader(final String shader) {
+ setTessellationEvaluationShader(shader, "");
+ }
+
+ /**
+ * Set the contents for our tessellation evaluation shader
+ *
+ * @param shader
+ * the shader contents.
+ * @param name
+ * a label for this shader, displayer upon shader errors.
+ */
+ public void setTessellationEvaluationShader(final String shader, final String name) {
+ _tessEvalShader = stringToByteBuffer(shader);
+ _tessellationEvaluationShaderName = name;
+ }
+
private ByteBuffer stringToByteBuffer(final String str) {
final byte[] bytes = str.getBytes();
final ByteBuffer buf = BufferUtils.createByteBuffer(bytes.length);
@@ -1152,6 +1292,9 @@
capsule.write(_vertShader, "vertShader", null);
capsule.write(_fragShader, "fragShader", null);
capsule.write(_geomShader, "geomShader", null);
+ capsule.write(_geomShader, "geomShader", null);
+ capsule.write(_tessControlShader, "tessControlShader", null);
+ capsule.write(_tessEvalShader, "tessEvalShader", null);
capsule.write(_useAttributeVBO, "useAttributeVBO", false);

if (_shaderDataLogic instanceof Savable) {
@@ -1167,6 +1310,8 @@
_vertShader = capsule.readByteBuffer("vertShader", null);
_fragShader = capsule.readByteBuffer("fragShader", null);
_geomShader = capsule.readByteBuffer("geomShader", null);
+ _tessControlShader = capsule.readByteBuffer("tessControlShader", null);
+ _tessEvalShader = capsule.readByteBuffer("tessEvalShader", null);
_useAttributeVBO = capsule.readBoolean("useAttributeVBO", false);

final Savable shaderDataLogic = capsule.readSavable("shaderDataLogic", null);




### Eclipse Workspace Patch 1.0
#P ardor3d-jogl2
Index: src/main/java/com/ardor3d/scene/state/jogl/JoglShaderObjectsStateUtil.java
===================================================================
--- src/main/java/com/ardor3d/scene/state/jogl/JoglShaderObjectsStateUtil.java (revision 57)
+++ src/main/java/com/ardor3d/scene/state/jogl/JoglShaderObjectsStateUtil.java (working copy)
@@ -117,11 +117,11 @@
gl.getGL2().glShaderSourceARB(state._geometryShaderID, 1, new String[] { new String(array) },
new int[] { array.length }, 0);

- // Compile the fragment shader
+ // Compile the geometry shader
final IntBuffer compiled = BufferUtils.createIntBuffer(1);
gl.getGL2().glCompileShaderARB(state._geometryShaderID);
gl.getGL2().glGetObjectParameterivARB(state._geometryShaderID, GL2.GL_OBJECT_COMPILE_STATUS_ARB, compiled);
- checkProgramError(compiled, state._geometryShaderID, state._vertexShaderName);
+ checkProgramError(compiled, state._geometryShaderID, state._geometryShaderName);

// Attach the program
gl.getGL2().glAttachObjectARB(state._programID, state._geometryShaderID);
@@ -130,6 +130,61 @@
state._geometryShaderID = -1;
}
}
+
+ if (caps.isTessellationShadersSupported()) {
+ if (state.getTessellationControlShader() != null) {
+ if (state._tessellationControlShaderID != -1) {
+ removeTessControlShader(state);
+ }
+
+ state._tessellationControlShaderID = gl.getGL2().glCreateShaderObjectARB(GL4.GL_TESS_CONTROL_SHADER);
+
+ // Create the sources
+ final byte array[] = new byte[state.getTessellationControlShader().limit()];
+ state.getTessellationControlShader().rewind();
+ state.getTessellationControlShader().get(array);
+ gl.getGL2().glShaderSourceARB(state._tessellationControlShaderID, 1, new String[] { new String(array) },
+ new int[] { array.length }, 0);
+
+ // Compile the tessellation control shader
+ final IntBuffer compiled = BufferUtils.createIntBuffer(1);
+ gl.getGL2().glCompileShaderARB(state._tessellationControlShaderID);
+ gl.getGL2().glGetObjectParameterivARB(state._tessellationControlShaderID, GL2.GL_OBJECT_COMPILE_STATUS_ARB, compiled);
+ checkProgramError(compiled, state._tessellationControlShaderID, state._tessellationControlShaderName);
+
+ // Attach the program
+ gl.getGL2().glAttachObjectARB(state._programID, state._tessellationControlShaderID);
+ } else if (state._tessellationControlShaderID != -1) {
+ removeTessControlShader(state);
+ state._tessellationControlShaderID = -1;
+ }
+ if (state.getTessellationEvaluationShader() != null) {
+ if (state._tessellationEvaluationShaderID != -1) {
+ removeTessEvalShader(state);
+ }
+
+ state._tessellationEvaluationShaderID = gl.getGL2().glCreateShaderObjectARB(GL4.GL_TESS_CONTROL_SHADER);
+
+ // Create the sources
+ final byte array[] = new byte[state.getTessellationEvaluationShader().limit()];
+ state.getTessellationEvaluationShader().rewind();
+ state.getTessellationEvaluationShader().get(array);
+ gl.getGL2().glShaderSourceARB(state._tessellationEvaluationShaderID, 1, new String[] { new String(array) },
+ new int[] { array.length }, 0);
+
+ // Compile the tessellation control shader
+ final IntBuffer compiled = BufferUtils.createIntBuffer(1);
+ gl.getGL2().glCompileShaderARB(state._tessellationEvaluationShaderID);
+ gl.getGL2().glGetObjectParameterivARB(state._tessellationEvaluationShaderID, GL2.GL_OBJECT_COMPILE_STATUS_ARB, compiled);
+ checkProgramError(compiled, state._tessellationEvaluationShaderID, state._tessellationEvaluationShaderName);
+
+ // Attach the program
+ gl.getGL2().glAttachObjectARB(state._programID, state._tessellationEvaluationShaderID);
+ } else if (state._tessellationEvaluationShaderID != -1) {
+ removeTessEvalShader(state);
+ state._tessellationEvaluationShaderID = -1;
+ }
+ }

gl.getGL2().glLinkProgramARB(state._programID);
checkLinkError(state._programID);
@@ -191,6 +246,26 @@
gl.getGL2().glDeleteObjectARB(state._geometryShaderID);
}
}
+
+ /** Removes the tessellation control shader */
+ private static void removeTessControlShader(final GLSLShaderObjectsState state) {
+ final GL gl = GLU.getCurrentGL();
+
+ if (state._tessellationControlShaderID != -1) {
+ gl.getGL2().glDetachObjectARB(state._programID, state._tessellationControlShaderID);
+ gl.getGL2().glDeleteObjectARB(state._tessellationControlShaderID);
+ }
+ }
+
+ /** Removes the tessellation evaluation shader */
+ private static void removeTessEvalShader(final GLSLShaderObjectsState state) {
+ final GL gl = GLU.getCurrentGL();
+
+ if (state._tessellationEvaluationShaderID != -1) {
+ gl.getGL2().glDetachObjectARB(state._programID, state._tessellationEvaluationShaderID);
+ gl.getGL2().glDeleteObjectARB(state._tessellationEvaluationShaderID);
+ }
+ }

/**
* Check for program errors. If an error is detected, program exits.
Index: src/main/java/com/ardor3d/renderer/jogl/JoglContextCapabilities.java
===================================================================
--- src/main/java/com/ardor3d/renderer/jogl/JoglContextCapabilities.java (revision 57)
+++ src/main/java/com/ardor3d/renderer/jogl/JoglContextCapabilities.java (working copy)
@@ -73,6 +73,8 @@

_geometryInstancingSupported = _glslSupported && gl.isExtensionAvailable("GL_EXT_draw_instanced");

+ _tessellationShadersSupported = gl.isExtensionAvailable("GL_ARB_tessellation_shader") && _glslSupported;
+
if (_glslSupported) {
gl.glGetIntegerv(GL2.GL_MAX_VERTEX_ATTRIBS_ARB, buf);
_maxGLSLVertexAttribs = buf.get(0);

[renanse]

Applied the changes to the core.

[gouessej]

Applied the changes to the core.

Thanks. I committed the changes in the renderer based on JOGL 2.0.