determine drawing mode by IBO count_per_element

Author: christian-rauch

include/pangolin/gl/glvbo.h

@@ -127,7 +127,12 @@ inline void RenderVboIbo(GlBuffer& vbo, GlBuffer& ibo, bool draw_mesh)
 
     if(draw_mesh) {
         ibo.Bind();
-        glDrawElements(GL_TRIANGLES, ibo.num_elements*ibo.count_per_element, ibo.datatype, 0);
+        if(ibo.count_per_element==1) {
+            glDrawElements(GL_TRIANGLE_STRIP,ibo.num_elements, ibo.datatype, 0);
+        }
+        else {
+            glDrawElements(GL_TRIANGLES,ibo.num_elements*ibo.count_per_element, ibo.datatype, 0);
+        }
         ibo.Unbind();
     }else{
         glDrawArrays(GL_POINTS, 0, vbo.num_elements);
@@ -173,7 +178,12 @@ inline void RenderVboIboCboNbo(GlBuffer& vbo, GlBuffer& ibo, GlBuffer& cbo, GlBu
 
     if(draw_mesh) {
         ibo.Bind();
-        glDrawElements(GL_TRIANGLE_STRIP,ibo.num_elements, ibo.datatype, 0);
+        if(ibo.count_per_element==1) {
+            glDrawElements(GL_TRIANGLE_STRIP,ibo.num_elements, ibo.datatype, 0);
+        }
+        else {
+            glDrawElements(GL_TRIANGLES,ibo.num_elements*ibo.count_per_element, ibo.datatype, 0);
+        }
         ibo.Unbind();
     }else{
         glDrawArrays(GL_POINTS, 0, vbo.num_elements);
@@ -207,7 +217,12 @@ inline void RenderVboIboNbo(GlBuffer& vbo, GlBuffer& ibo, GlBuffer& nbo, bool dr
 
     if(draw_mesh) {
         ibo.Bind();
-        glDrawElements(GL_TRIANGLE_STRIP,ibo.num_elements, ibo.datatype, 0);
+        if(ibo.count_per_element==1) {
+            glDrawElements(GL_TRIANGLE_STRIP,ibo.num_elements, ibo.datatype, 0);
+        }
+        else {
+            glDrawElements(GL_TRIANGLES,ibo.num_elements*ibo.count_per_element, ibo.datatype, 0);
+        }
         ibo.Unbind();
     }else{
         glDrawArrays(GL_POINTS, 0, vbo.num_elements);