More work on metavoxel editing (grid, etc.)

interface/resources/shaders/grid.frag

@@ -0,0 +1,13 @@
+#version 120
+
+//
+//  grid.frag
+//  fragment shader
+//
+//  Created by Andrzej Kapolka on 1/21/14.
+//  Copyright (c) 2014 High Fidelity, Inc. All rights reserved.
+//
+
+void main(void) {
+    gl_FragColor = vec4(gl_Color.rgb, exp(-0.25 / gl_FragCoord.w));
+}

interface/src/renderer/GeometryCache.cpp

@@ -7,7 +7,11 @@
 
 #include <cmath>
 
+// include this before QOpenGLBuffer, which includes an earlier version of OpenGL
+#include "InterfaceConfig.h"
+
 #include <QNetworkReply>
+#include <QOpenGLBuffer>
 
 #include "Application.h"
 #include "GeometryCache.h"
@@ -241,6 +245,50 @@ void GeometryCache::renderHalfCylinder(int slices, int stacks) {
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
 }
 
+void GeometryCache::renderGrid(int xDivisions, int yDivisions) {
+    QOpenGLBuffer& buffer = _gridBuffers[IntPair(xDivisions, yDivisions)];
+    int vertices = (xDivisions + 1 + yDivisions + 1) * 2;
+    if (!buffer.isCreated()) {
+        GLfloat* vertexData = new GLfloat[vertices * 2];
+        GLfloat* vertex = vertexData;
+        for (int i = 0; i <= xDivisions; i++) {
+            float x = (float)i / xDivisions;
+        
+            *(vertex++) = x;
+            *(vertex++) = 0.0f;
+            
+            *(vertex++) = x;
+            *(vertex++) = 1.0f;
+        }
+        for (int i = 0; i <= yDivisions; i++) {
+            float y = (float)i / yDivisions;
+            
+            *(vertex++) = 0.0f;
+            *(vertex++) = y;
+            
+            *(vertex++) = 1.0f;
+            *(vertex++) = y;
+        }
+        buffer.create();
+        buffer.setUsagePattern(QOpenGLBuffer::StaticDraw);
+        buffer.bind();
+        buffer.allocate(vertexData, vertices * 2 * sizeof(GLfloat));
+        delete[] vertexData;
+        
+    } else {
+        buffer.bind();
+    }
+    glEnableClientState(GL_VERTEX_ARRAY);
+    
+    glVertexPointer(2, GL_FLOAT, 0, 0);
+    
+    glDrawArrays(GL_LINES, 0, vertices);
+    
+    glDisableClientState(GL_VERTEX_ARRAY);
+    
+    buffer.release();
+}
+
 QSharedPointer<NetworkGeometry> GeometryCache::getGeometry(const QUrl& url) {
     QSharedPointer<NetworkGeometry> geometry = _networkGeometry.value(url);
     if (geometry.isNull()) {

interface/src/renderer/GeometryCache.h

@@ -19,6 +19,7 @@
 #include "InterfaceConfig.h"
 
 class QNetworkReply;
+class QOpenGLBuffer;
 
 class NetworkGeometry;
 class NetworkMesh;
@@ -33,6 +34,7 @@ public:
     void renderHemisphere(int slices, int stacks);
     void renderSquare(int xDivisions, int yDivisions);
     void renderHalfCylinder(int slices, int stacks);
+    void renderGrid(int xDivisions, int yDivisions);
 
     /// Loads geometry from the specified URL.
     QSharedPointer<NetworkGeometry> getGeometry(const QUrl& url);
@@ -45,6 +47,7 @@ private:
     QHash<IntPair, VerticesIndices> _hemisphereVBOs;
     QHash<IntPair, VerticesIndices> _squareVBOs;
     QHash<IntPair, VerticesIndices> _halfCylinderVBOs;
+    QHash<IntPair, QOpenGLBuffer> _gridBuffers;
     
     QHash<QUrl, QWeakPointer<NetworkGeometry> > _networkGeometry;
 };

interface/src/ui/MetavoxelEditorDialog.cpp

@@ -79,6 +79,13 @@ MetavoxelEditorDialog::MetavoxelEditorDialog() :
     connect(Application::getInstance(), SIGNAL(renderingInWorldInterface()), SLOT(render()));
     
     show();
+    
+    if (_gridProgram.isLinked()) {
+        return;
+    }
+    switchToResourcesParentIfRequired();
+    _gridProgram.addShaderFromSourceFile(QGLShader::Fragment, "resources/shaders/grid.frag");
+    _gridProgram.link();
 }
 
 void MetavoxelEditorDialog::updateValueEditor() {
@@ -138,7 +145,44 @@ void MetavoxelEditorDialog::updateGridPosition() {
 }
 
 void MetavoxelEditorDialog::render() {
+    const float GRID_BRIGHTNESS = 0.5f;
+    glColor3f(GRID_BRIGHTNESS, GRID_BRIGHTNESS, GRID_BRIGHTNESS);
+    glDisable(GL_LIGHTING);
     
+    glPushMatrix();
+    
+    glm::quat rotation;
+    switch (_gridPlane->currentIndex()) {
+        case GRID_PLANE_XZ:
+            rotation = glm::angleAxis(90.0f, 1.0f, 0.0f, 0.0f);
+            glRotatef(-90.0f, 1.0f, 0.0f, 0.0f);
+            break;
+            
+        case GRID_PLANE_YZ:
+            rotation = glm::angleAxis(-90.0f, 0.0f, 1.0f, 0.0f);
+            glRotatef(90.0f, 0.0f, 1.0f, 0.0f);
+            break;
+    }
+    
+    // center the grid around the camera position on the plane
+    glm::vec3 rotated = rotation * Application::getInstance()->getCamera()->getPosition();
+    float spacing = _gridSpacing->value();
+    const int GRID_DIVISIONS = 300;
+    glTranslatef(spacing * (floor(rotated.x / spacing) - GRID_DIVISIONS / 2),
+        spacing * (floor(rotated.y / spacing) - GRID_DIVISIONS / 2), _gridPosition->value());
+    
+    float scale = GRID_DIVISIONS * spacing;
+    glScalef(scale, scale, scale);
+    
+    _gridProgram.bind();
+    
+    Application::getInstance()->getGeometryCache()->renderGrid(GRID_DIVISIONS, GRID_DIVISIONS);
+    
+    _gridProgram.release();
+    
+    glPopMatrix();
+    
+    glEnable(GL_LIGHTING);
 }
 
 void MetavoxelEditorDialog::updateAttributes(const QString& select) {
@@ -164,3 +208,5 @@ QString MetavoxelEditorDialog::getSelectedAttribute() const {
     QList<QListWidgetItem*> selectedItems = _attributes->selectedItems();
     return selectedItems.isEmpty() ? QString() : selectedItems.first()->text();
 }
+
+ProgramObject MetavoxelEditorDialog::_gridProgram;

interface/src/ui/MetavoxelEditorDialog.h

@@ -11,6 +11,8 @@
 
 #include <QDialog>
 
+#include "renderer/ProgramObject.h"
+
 class QComboBox;
 class QDoubleSpinBox;
 class QGroupBox;
@@ -42,6 +44,8 @@ private:
     QDoubleSpinBox* _gridSpacing;
     QDoubleSpinBox* _gridPosition;
     QGroupBox* _value;
+    
+    static ProgramObject _gridProgram;
 };
 
 #endif /* defined(__interface__MetavoxelEditorDialog__) */