* added detection of double includes in tgt::ShaderPreprocessor

 * added gradient fragment shader include
 * implemented first hit normal computation to SimpleRaycaster

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@294 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

src/tumvis/core/datastructures/imagedatagl.cpp

@@ -119,6 +119,8 @@ namespace TUMVis {
             shader->setUniform(texUniform + "._texture", texUnit.getUnitNumber());
             shader->setUniform(texUniform + "._size", tgt::vec3(_size));
             shader->setUniform(texUniform + "._sizeRCP", tgt::vec3(1.f) / tgt::vec3(_size));
+            shader->setUniform(texUniform + "._voxelSize", _mappingInformation.getVoxelSize());
+            shader->setUniform(texUniform + "._voxelSizeRCP", tgt::vec3(1.f) / _mappingInformation.getVoxelSize());
             break;
 
         default:

src/tumvis/core/glsl/tools/gradient.frag

+#include "tools/texture3d.frag"
+
+/**
+ * Compute the gradient using forward differences on the texture's alpha channel.
+ * \param   tex         3D texture to calculate gradients for
+ * \param   texCoords   Lookup position in texture coordinates
+ */
+vec3 computeGradientForwardDifferences(in Texture3D tex, in vec3 texCoords) {
+    vec3 offset = tex._sizeRCP;
+    float v = getElement3DNormalized(tex, texCoords).a;
+    float dx = getElement3DNormalized(tex, texCoords + vec3(offset.x, 0.0, 0.0)).a;
+    float dy = getElement3DNormalized(tex, texCoords + vec3(0, offset.y, 0)).a;
+    float dz = getElement3DNormalized(tex, texCoords + vec3(0, 0, offset.z)).a;
+    return vec3(v - dx, v - dy, v - dz) * tex._voxelSize;
+}
+
+/**
+ * Compute the gradient using central differences on the texture's alpha channel.
+ * \param   tex         3D texture to calculate gradients for
+ * \param   texCoords   Lookup position in texture coordinates
+ */
+vec3 computeGradientCentralDifferences(in Texture3D tex, in vec3 texCoords) {
+    vec3 offset = tex._sizeRCP;
+    float dx = getElement3DNormalized(tex, texCoords + vec3(offset.x, 0.0, 0.0)).a;
+    float dy = getElement3DNormalized(tex, texCoords + vec3(0, offset.y, 0)).a;
+    float dz = getElement3DNormalized(tex, texCoords + vec3(0, 0, offset.z)).a;
+    float mdx = getElement3DNormalized(tex, texCoords + vec3(-offset.x, 0, 0)).a;
+    float mdy = getElement3DNormalized(tex, texCoords + vec3(0, -offset.y, 0)).a;
+    float mdz = getElement3DNormalized(tex, texCoords + vec3(0, 0, -offset.z)).a;
+    return vec3(mdx - dx, mdy - dy, mdz - dz) * tex._voxelSize * vec3(0.5);
+}
+
+
+/**
+ * Compute the gradient using filtered central differences on the texture's alpha channel.
+ * \param   tex         3D texture to calculate gradients for
+ * \param   texCoords   Lookup position in texture coordinates
+ */
+vec3 computeGradientFilteredCentralDifferences(in Texture3D tex, in vec3 texCoords) {
+    vec3 offset = tex._sizeRCP;
+    vec3 g0 = computeGradientCentralDifferences(tex, texCoords);
+    vec3 g1 = computeGradientCentralDifferences(tex, texCoords + vec3(-offset.x, -offset.y, -offset.z));
+    vec3 g2 = computeGradientCentralDifferences(tex, texCoords + vec3( offset.x,  offset.y,  offset.z));
+    vec3 g3 = computeGradientCentralDifferences(tex, texCoords + vec3(-offset.x,  offset.y, -offset.z));
+    vec3 g4 = computeGradientCentralDifferences(tex, texCoords + vec3( offset.x, -offset.y,  offset.z));
+    vec3 g5 = computeGradientCentralDifferences(tex, texCoords + vec3(-offset.x, -offset.y,  offset.z));
+    vec3 g6 = computeGradientCentralDifferences(tex, texCoords + vec3( offset.x,  offset.y, -offset.z));
+    vec3 g7 = computeGradientCentralDifferences(tex, texCoords + vec3(-offset.x,  offset.y,  offset.z));
+    vec3 g8 = computeGradientCentralDifferences(tex, texCoords + vec3( offset.x, -offset.y, -offset.z));
+    vec3 mix0 = mix(mix(g1, g2, 0.5), mix(g3, g4, 0.5), 0.5);
+    vec3 mix1 = mix(mix(g5, g6, 0.5), mix(g7, g8, 0.5), 0.5);
+    return mix(g0, mix(mix0, mix1, 0.5), 0.75);
+}

src/tumvis/core/glsl/tools/texture3d.frag

@@ -35,6 +35,10 @@ struct Texture3D {
     // Texture size
     vec3 _size;
     vec3 _sizeRCP;
+
+    // Voxel spacing
+    vec3 _voxelSize;
+    vec3 _voxelSizeRCP;
 };
 
 /**

src/tumvis/ext/tgt/shadermanager.cpp

@@ -92,32 +92,36 @@ void ShaderPreprocessor::parsePart(const std::string& input, const std::string&
             string filename(line, pos + 1, end - pos - 1);
             filename = ShdrMgr.completePath(filename);
 
-            File* file = FileSys.open(filename);
-            string content;
-            if ((!file) || (!file->isOpen())) {
-                LERROR("Cannot open shader include '" << filename << "' in " << resolveLineNumber(activeLine_, lineTracker_));
+            if (includedFilenames_.find(filename) == includedFilenames_.end()) {
+                File* file = FileSys.open(filename);
+                string content;
+                if ((!file) || (!file->isOpen())) {
+                    LERROR("Cannot open shader include '" << filename << "' in " << resolveLineNumber(activeLine_, lineTracker_));
+                }
+                else {
+                    size_t len = file->size();
+                    // check if file is empty
+                    if (len == 0)
+                        content = "";
+                    else
+                        content = file->getAsString();
+                    file->close();
+
+                    outputComment("BEGIN INCLUDE " + filename, "BEGIN");
+
+                    if (!content.empty() && content[content.size() - 1] != '\n')
+                        content += "\n";
+
+                    parsePart(content, filename);
+
+                    outputComment("END INCLUDE " + filename, "END");
+
+                    lineTracker_.push_back(ShaderObject::LineInfo(activeLine_, name, locallinenumber + 1));
+                }
+                delete file;
+
+                includedFilenames_.insert(filename);
             }
-            else {
-                size_t len = file->size();
-                // check if file is empty
-                if (len == 0)
-                    content = "";
-                else
-                    content = file->getAsString();
-                file->close();
-
-                outputComment("BEGIN INCLUDE " + filename, "BEGIN");
-
-                if (!content.empty() && content[content.size() - 1] != '\n')
-                    content += "\n";
-
-                parsePart(content, filename);
-
-                outputComment("END INCLUDE " + filename, "END");
-
-                lineTracker_.push_back(ShaderObject::LineInfo(activeLine_, name, locallinenumber + 1));
-            }
-            delete file;
         } else {
             result_ << line << "\n";
             activeLine_++;
@@ -129,6 +133,7 @@ void ShaderPreprocessor::parse() {
     activeLine_ = 1;
     lineTracker_.clear();
     result_.clear();
+    includedFilenames_.clear();
 
     outputComment("BEGIN GLOBAL HEADER");
     parsePart(ShdrMgr.getGlobalHeader(), "GLOBAL HEADER");

src/tumvis/ext/tgt/shadermanager.h

@@ -26,6 +26,7 @@
 #define TGT_SHADERMANAGER_H
 
 #include <list>
+#include <set>
 #include <string>
 
 #include "tgt/exception.h"
@@ -542,6 +543,7 @@ protected:
 
     ShaderObject* shd_;
     std::vector<ShaderObject::LineInfo>& lineTracker_; ///< keeps track of line numbers when includes are used
+    std::set<std::string> includedFilenames_;           ///< list of all filenames that have already been included (to avoid double inclusion)
     int activeLine_;
     std::ostringstream result_;
 

src/tumvis/modules/vis/simpleraycaster.cpp

@@ -51,10 +51,11 @@ namespace TUMVis {
     void SimpleRaycaster::processImpl(DataContainer& data) {
         ImageDataRenderTarget* output = new ImageDataRenderTarget(tgt::svec3(_renderTargetSize.getValue(), 1));
         output->createAndAttachTexture(GL_RGBA32F);
+        output->createAndAttachTexture(GL_RGBA32F);
         output->activate();
 
-        GLenum buffers[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 };
-        glDrawBuffers(2, buffers);
+        GLenum buffers[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 , GL_COLOR_ATTACHMENT2 };
+        glDrawBuffers(3, buffers);
 
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
         glDepthFunc(GL_ALWAYS);

src/tumvis/modules/vis/simpleraycaster.frag

@@ -28,9 +28,11 @@
 
 #version 330
 
-layout(location = 0) out vec4 out_Color;         ///< outgoing fragment color
-layout(location = 1) out vec4 out_FHP;           ///< outgoing fragment first hitpoint
+layout(location = 0) out vec4 out_Color;     ///< outgoing fragment color
+layout(location = 1) out vec4 out_FHP;       ///< outgoing fragment first hitpoint
+layout(location = 2) out vec4 out_FHN;       ///< outgoing fragment first hit normal
 
+#include "tools/gradient.frag"
 #include "tools/raycasting.frag"
 #include "tools/texture2d.frag"
 #include "tools/texture3d.frag"
@@ -77,7 +79,7 @@ vec4 performRaycasting(in vec3 entryPoint, in vec3 exitPoint, in vec2 texCoords)
 
         // perform compositing
         if (color.a > 0.0) {
-            // accomodate for variable sampling rates (base interval defined by mod_compositing.frag)
+            // accomodate for variable sampling rates
             color.a = 1.0 - pow(1.0 - color.a, _samplingStepSize * SAMPLING_BASE_INTERVAL_RCP);
             result.rgb = mix(color.rgb, result.rgb, result.a);
             result.a = result.a + (1.0 -result.a) * color.a;
@@ -87,6 +89,7 @@ vec4 performRaycasting(in vec3 entryPoint, in vec3 exitPoint, in vec2 texCoords)
         if (firstHitT < 0.0 && result.a > 0.0) {
             firstHitT = t;
             out_FHP = vec4(samplePosition, 1.0);
+            out_FHN = vec4(normalize(computeGradientCentralDifferences(_volume, samplePosition)), 1.0);
         }
 
         // early ray termination