add callSubList possibility in Drawe

include/Utils/drawer.h

@@ -90,8 +90,9 @@ public:
 	/**
 	 * as glBegin, but need a newList call before
 	 * @param mode: POINTS, LINES, LINE_LOOP, TRIANGLES, QUADS, POLYGON, etc..
+	 * @return index of subdrawing possible call
 	 */
-	void begin(GLenum mode);
+	int begin(GLenum mode);
 
 	/**
 	 * as glEnd
@@ -131,6 +132,16 @@ public:
 	 */
 	void callList(float opacity = 1.0f);
 
+	/**
+	 * call a sub-list (index return by begin (0,1,...)
+	 */
+	void callSubList(int index, float opacity = 1.0f);
+
+	/**
+	 * call a set of sub-lists
+	 */
+	void callSubLists(std::vector<int> indices, float opacity);
+
 	/**
 	 * use as glLineWidth
 	 */

src/Utils/drawer.cpp

@@ -74,12 +74,14 @@ void Drawer::pointSize(float ps)
 	m_currentSize = ps;
 }
 
-void Drawer::begin(GLenum mode)
+int Drawer::begin(GLenum mode)
 {
+	int res = m_begins.size();
 	if (mode == GL_POINTS)
 		m_begins.push_back(PrimParam(m_dataPos.size(), mode, m_currentSize));
 	else
 		m_begins.push_back(PrimParam(m_dataPos.size(), mode, m_currentWidth));
+	return res;
 }
 
 void Drawer::end()
@@ -186,6 +188,47 @@ void Drawer::callList(float opacity)
 }
 
 
+void Drawer::callSubList(int index, float opacity)
+{
+	if (index >= int(m_begins.size()))
+		return;
+
+	m_shader->setOpacity(opacity);
+
+	m_shader->enableVertexAttribs();
+
+	PrimParam* pp = & (m_begins[index]);
+
+	if (pp->mode == GL_POINTS)
+		glPointSize(pp->width);
+	if ((pp->mode == GL_LINES) || (pp->mode == GL_LINE_LOOP))
+		glLineWidth(pp->width);
+	glDrawArrays(pp->mode, pp->begin, pp->nb);
+
+	m_shader->disableVertexAttribs();
+}
+
+void Drawer::callSubLists(std::vector<int> indices, float opacity)
+{
+	m_shader->setOpacity(opacity);
+
+	m_shader->enableVertexAttribs();
+
+	for (std::vector<int>::iterator it = indices.begin(); it != indices.end(); ++it)
+		if (*it < int(m_begins.size()))
+		{
+			PrimParam* pp = & (m_begins[*it]);
+
+			if (pp->mode == GL_POINTS)
+				glPointSize(pp->width);
+			if ((pp->mode == GL_LINES) || (pp->mode == GL_LINE_LOOP))
+				glLineWidth(pp->width);
+			glDrawArrays(pp->mode, pp->begin, pp->nb);
+		}
+
+	m_shader->disableVertexAttribs();
+}
+
 
 void Drawer::toSVG(Utils::SVG::SVGOut& svg)
 {