内容表

• 关于
• Draw
  • 用法
• 范例
• 延伸阅读

关于

Many classic plugin classes can implement a "Draw" function that allows to draw something in the editor viewport. These "Draw" functions differ from class to class.

Draw

A "Draw" function can be found in the following classic base classes:

• ObjectData::Draw() : Is called for each object plugin instance.
• TagData::Draw() : Is called for each tag plugin instance.
• ToolData::Draw() : Is called for the tool plugin.
• SceneHookData::Draw() : Is called for the SceneHook plugin.
• MaterialData::Draw() : Is called for every object/tag pair that uses the material plugin instance.
• ShaderData::Draw() : Is called for each shader plugin instance.
• SnapData::Draw() : Is called for the snap mode plugin.

注意

To avoid drawing order problems the drawing operations of multiple objects or tags can be replaced by the use of the "Draw" function in a SceneHookData 插件。

用法

A "Draw" function is typically called multiple times during the drawing process for different draw passes and for each open viewport window. The given BaseDraw object represents a viewport window and is used to draw in that window.

This is an example implementation of ObjectData::Draw() :

DRAWRESULT Draw( BaseObject * op, DRAWPASS drawpass, BaseDraw * bd, BaseDrawHelp * bh) { // only draw in the DRAWPASS_OBJECT if (drawpass != DRAWPASS_OBJECT) return SUPER::Draw(op, drawpass, bd, bh);

// set the matrix / space for the following drawing operations // in this case, use the object's matrix const 矩阵 & mg = bh-> GetMg (); bd-> SetMatrix_Matrix (op, mg);

// set line width const GeData oldValue = bd-> GetDrawParam ( DRAW_PARAMETER_LINEWIDTH ); bd-> SetDrawParam ( DRAW_PARAMETER_LINEWIDTH , GeData { 3.0 });

// draw lines bd-> SetPen ( 向量 (1.0, 0.0, 0.0)); bd-> DrawLine ( 向量 (-100, 0, 0), 向量 (100, 0, 0), NOCLIP_D );