feat: Add sketch creation with plane selection, oriented grid and labeled axes

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

src/SketchGrid.cpp

@@ -0,0 +1,112 @@
+#include "SketchGrid.h"
+
+SketchGrid::SketchGrid()
+{
+}
+
+SketchGrid::~SketchGrid()
+{
+}
+
+void SketchGrid::initializeGL()
+{
+    initializeOpenGLFunctions();
+}
+
+void SketchGrid::paintGL(SketchPlane plane, const QMatrix4x4& projection, const QMatrix4x4& modelview)
+{
+    glMatrixMode(GL_PROJECTION);
+    glLoadMatrixf(projection.constData());
+    glMatrixMode(GL_MODELVIEW);
+    glLoadMatrixf(modelview.constData());
+
+    glPushAttrib(GL_LINE_BIT | GL_POINT_BIT | GL_CURRENT_BIT);
+    glDisable(GL_DEPTH_TEST);
+
+    drawGridLines(plane);
+    drawAxes(plane);
+
+    glEnable(GL_DEPTH_TEST);
+    glPopAttrib();
+}
+
+void SketchGrid::drawGridLines(SketchPlane plane)
+{
+    const int gridSize = 50;
+    const float darkFactor = 0.8f;
+
+    // Lighter lines
+    glColor3f(0.5f, 0.5f, 0.5f);
+    glLineWidth(1.0f);
+    glBegin(GL_LINES);
+    for (int i = -gridSize; i <= gridSize; ++i)
+    {
+        if (i == 0 || i % 5 == 0) continue;
+        if (plane == XY) {
+            glVertex3f(i, -gridSize, 0); glVertex3f(i, gridSize, 0);
+            glVertex3f(-gridSize, i, 0); glVertex3f(gridSize, i, 0);
+        } else if (plane == XZ) {
+            glVertex3f(i, 0, -gridSize); glVertex3f(i, 0, gridSize);
+            glVertex3f(-gridSize, 0, i); glVertex3f(gridSize, 0, i);
+        } else { // YZ
+            glVertex3f(0, i, -gridSize); glVertex3f(0, i, gridSize);
+            glVertex3f(0, -gridSize, i); glVertex3f(0, gridSize, i);
+        }
+    }
+    glEnd();
+
+    // Darker lines
+    glColor3f(0.5f * darkFactor, 0.5f * darkFactor, 0.5f * darkFactor);
+    glLineWidth(1.5f);
+    glBegin(GL_LINES);
+    for (int i = -gridSize; i <= gridSize; i += 5)
+    {
+        if (i == 0) continue;
+        if (plane == XY) {
+            glVertex3f(i, -gridSize, 0); glVertex3f(i, gridSize, 0);
+            glVertex3f(-gridSize, i, 0); glVertex3f(gridSize, i, 0);
+        } else if (plane == XZ) {
+            glVertex3f(i, 0, -gridSize); glVertex3f(i, 0, gridSize);
+            glVertex3f(-gridSize, 0, i); glVertex3f(gridSize, 0, i);
+        } else { // YZ
+            glVertex3f(0, i, -gridSize); glVertex3f(0, i, gridSize);
+            glVertex3f(0, -gridSize, i); glVertex3f(0, gridSize, i);
+        }
+    }
+    glEnd();
+}
+
+void SketchGrid::drawAxes(SketchPlane plane)
+{
+    const int axisLength = 50;
+
+    glLineWidth(2.0f);
+    glBegin(GL_LINES);
+
+    // X Axis (Red)
+    if (plane == XY || plane == XZ) {
+        glColor3f(1.0f, 0.0f, 0.0f);
+        glVertex3f(-axisLength, 0, 0);
+        glVertex3f(axisLength, 0, 0);
+    }
+    // Y Axis (Green)
+    if (plane == XY || plane == YZ) {
+        glColor3f(0.0f, 1.0f, 0.0f);
+        glVertex3f(0, -axisLength, 0);
+        glVertex3f(0, axisLength, 0);
+    }
+    // Z Axis (Blue)
+    if (plane == XZ || plane == YZ) {
+        glColor3f(0.0f, 0.0f, 1.0f);
+        glVertex3f(0, 0, -axisLength);
+        glVertex3f(0, 0, axisLength);
+    }
+    glEnd();
+    
+    // Origin dot
+    glPointSize(5.0f);
+    glColor3f(1.0f, 1.0f, 1.0f); // White
+    glBegin(GL_POINTS);
+    glVertex3f(0, 0, 0);
+    glEnd();
+}