/// <summary>
/// 计算opengl画布的大小。
/// </summary>
/// <param name="args"></param>
static void CalculateViewport(IUILayoutArgs args)
{
int[] viewport = new int[4];
GL.GetInteger(GetTarget.Viewport, viewport);
args.viewportWidth = viewport[2];
args.viewportHeight = viewport[3];
}
/// <summary>
/// 获取为UI元素布局所需的参数对象。
/// </summary>
/// <param name="uiElement"></param>
/// <returns></returns>
public static IUILayoutArgs GetArgs(this IUILayout uiElement)
{
var args = new IUILayoutArgs();
CalculateViewport(args);
CalculateCoords(uiElement, args.viewportWidth, args.viewportHeight, args);
return args;
}
/// <summary>
/// 获取为UI元素布局所需的参数对象。
/// </summary>
/// <param name="uiElement"></param>
/// <returns></returns>
public static IUILayoutArgs GetArgs(this IUILayout uiElement)
{
var args = new IUILayoutArgs();
CalculateViewport(args);
CalculateCoords(uiElement, args.viewportWidth, args.viewportHeight, args);
return(args);
}
/// <summary>
/// 计算opengl画布的大小。
/// </summary>
/// <param name="args"></param>
static void CalculateViewport(IUILayoutArgs args)
{
int[] viewport = new int[4];
GL.GetInteger(GetTarget.Viewport, viewport);
args.viewportWidth = viewport[2];
args.viewportHeight = viewport[3];
}
/// <summary>
/// 根据UI元素的布局设定，计算其应有的宽高及其在ortho()中应有的参数。
/// </summary>
/// <param name="uiElement"></param>
/// <param name="viewportWidth"></param>
/// <param name="viewportHeight"></param>
/// <param name="args"></param>
static void CalculateCoords(IUILayout uiElement, int viewportWidth, int viewportHeight, IUILayoutArgs args)
{
IUILayoutParam param = uiElement.Param;
if ((param.Anchor & leftRightAnchor) == leftRightAnchor)
{
args.UIWidth = viewportWidth - param.Margin.Left - param.Margin.Right;
if (args.UIWidth < 0) { args.UIWidth = 0; }
}
else
{
args.UIWidth = param.Size.Width;
}
if ((param.Anchor & topBottomAnchor) == topBottomAnchor)
{
args.UIHeight = viewportHeight - param.Margin.Top - param.Margin.Bottom;
if (args.UIHeight < 0) { args.UIHeight = 0; }
}
else
{
args.UIHeight = param.Size.Height;
}
if ((param.Anchor & leftRightAnchor) == AnchorStyles.None)
{
args.left = -(args.UIWidth / 2
+ (viewportWidth - args.UIWidth)
* ((double)param.Margin.Left / (double)(param.Margin.Left + param.Margin.Right)));
}
else if ((param.Anchor & leftRightAnchor) == AnchorStyles.Left)
{
args.left = -(args.UIWidth / 2 + param.Margin.Left);
}
else if ((param.Anchor & leftRightAnchor) == AnchorStyles.Right)
{
args.left = -(viewportWidth - args.UIWidth / 2 - param.Margin.Right);
}
else // if ((Anchor & leftRightAnchor) == leftRightAnchor)
{
args.left = -(args.UIWidth / 2 + param.Margin.Left);
}
if ((param.Anchor & topBottomAnchor) == AnchorStyles.None)
{
args.bottom = -viewportHeight / 2;
args.bottom = -(args.UIHeight / 2
+ (viewportHeight - args.UIHeight)
* ((double)param.Margin.Bottom / (double)(param.Margin.Bottom + param.Margin.Top)));
}
else if ((param.Anchor & topBottomAnchor) == AnchorStyles.Bottom)
{
args.bottom = -(args.UIHeight / 2 + param.Margin.Bottom);
}
else if ((param.Anchor & topBottomAnchor) == AnchorStyles.Top)
{
args.bottom = -(viewportHeight - args.UIHeight / 2 - param.Margin.Top);
}
else // if ((Anchor & topBottomAnchor) == topBottomAnchor)
{
args.bottom = -(args.UIHeight / 2 + param.Margin.Bottom);
}
}
/// <summary>
/// 获取此UI元素的投影矩阵、视图矩阵和模型矩阵
/// </summary>
/// <param name="uiElement"></param>
/// <param name="projectionMatrix"></param>
/// <param name="viewMatrix"></param>
/// <param name="modelMatrix"></param>
/// <param name="camera">如果为null，会以glm.lookAt(new vec3(0, 0, 1), new vec3(0, 0, 0), new vec3(0, 1, 0))计算默认值。</param>
/// <param name="maxDepth">UI元素的外接球半径的倍数。</param>
public static void GetMatrix(this IUILayout uiElement,
out mat4 projectionMatrix, out mat4 viewMatrix, out mat4 modelMatrix,
IViewCamera camera = null, float maxDepth = 2.0f)
{
IUILayoutArgs args = uiElement.GetArgs();
float max = (float)Math.Max(args.UIWidth, args.UIHeight);
{
//projectionMatrix = glm.ortho((float)args.left, (float)args.right, (float)args.bottom, (float)args.top,
// TODO: / 2后与legacy opengl的UI元素显示就完全一致了。为什么？？？
projectionMatrix = glm.ortho((float)args.left / 2, (float)args.right / 2, (float)args.bottom / 2, (float)args.top / 2,
uiElement.Param.zNear, uiElement.Param.zFar);
// 下面注释掉的代码是用来测试legacy OpenGL的matrix与GLM库计算的matrix是否相同用的。已经证明了两者完全相同，此处仅作留念+以防万一。
//{
// float[] matrix = new float[16];
// GL.MatrixMode(GL.GL_PROJECTION);
// GL.PushMatrix();
// GL.GetFloat(GetTarget.ProjectionMatrix, matrix);
// GL.LoadIdentity();
// GL.GetFloat(GetTarget.ProjectionMatrix, matrix);
// GL.Ortho(args.left / 2, args.right / 2, args.bottom / 2, args.top / 2, uiElement.Param.zNear, uiElement.Param.zFar);
// GL.GetFloat(GetTarget.ProjectionMatrix, matrix);// this equals projectionMatrix
// GL.PopMatrix();
//}
// 把UI元素移到ortho长方体的最靠近camera的地方，这样就可以把UI元素放到OpenGL最前方。
projectionMatrix = glm.translate(projectionMatrix, new vec3(0, 0, uiElement.Param.zFar - max / 2 * maxDepth));
}
{
// UI元素不在三维场景中，所以其Camera可以是null。
if (camera == null)
{
//viewMatrix = glm.lookAt(new vec3(0, 0, 1), new vec3(0, 0, 0), new vec3(0, 1, 0));
viewMatrix = glm.lookAt(
ScientificCamera.defaultPosition,
ScientificCamera.defaultTarget,
ScientificCamera.defaultUpVector);
}
else
{
vec3 position = camera.Position - camera.Target;
position.Normalize();
viewMatrix = glm.lookAt(position, new vec3(0, 0, 0), camera.UpVector);
}
// 下面注释掉的代码是用来测试legacy OpenGL的matrix与GLM库计算的matrix是否相同用的。已经证明了两者完全相同，此处仅作留念+以防万一。
//{
// float[] matrix = new float[16];
// GL.MatrixMode(GL.GL_MODELVIEW);
// GL.PushMatrix();
// GL.GetFloat(GetTarget.ModelviewMatix, matrix);
// GL.LoadIdentity();
// GL.GetFloat(GetTarget.ModelviewMatix, matrix);
// if(camera==null)
// {
// GL.gluLookAt(0, 0, 1, 0, 0, 0, 0, 1, 0);
// }
// else
// {
// vec3 position = camera.Position - camera.Target;
// position.Normalize();
// GL.gluLookAt(position.x, position.y, position.z, 0, 0, 0, camera.UpVector.x, camera.UpVector.y, camera.UpVector.z);
// }
// GL.GetFloat(GetTarget.ModelviewMatix, matrix);// this equals viewMatrix
// GL.PopMatrix();
//}
}
{
modelMatrix = glm.scale(mat4.identity(), new vec3(args.UIWidth / 2, args.UIHeight / 2, max / 2));
// 下面注释掉的代码是用来测试legacy OpenGL的matrix与GLM库计算的matrix是否相同用的。已经证明了两者完全相同，此处仅作留念+以防万一。
//{
// float[] matrix = new float[16];
// GL.MatrixMode(GL.GL_MODELVIEW);
// GL.PushMatrix();
// GL.GetFloat(GetTarget.ModelviewMatix, matrix);
// GL.LoadIdentity();
// GL.GetFloat(GetTarget.ModelviewMatix, matrix);
// GL.Scale(args.UIWidth / 2, args.UIHeight / 2, max / 2);
// GL.GetFloat(GetTarget.ModelviewMatix, matrix);// this equals modelMatrix
// GL.PopMatrix();
//}
}
}
/// <summary>
/// 根据UI元素的布局设定，计算其应有的宽高及其在ortho()中应有的参数。
/// </summary>
/// <param name="uiElement"></param>
/// <param name="viewportWidth"></param>
/// <param name="viewportHeight"></param>
/// <param name="args"></param>
static void CalculateCoords(IUILayout uiElement, int viewportWidth, int viewportHeight, IUILayoutArgs args)
{
IUILayoutParam param = uiElement.Param;
if ((param.Anchor & leftRightAnchor) == leftRightAnchor)
{
args.UIWidth = viewportWidth - param.Margin.Left - param.Margin.Right;
if (args.UIWidth < 0)
{
args.UIWidth = 0;
}
}
else
{
args.UIWidth = param.Size.Width;
}
if ((param.Anchor & topBottomAnchor) == topBottomAnchor)
{
args.UIHeight = viewportHeight - param.Margin.Top - param.Margin.Bottom;
if (args.UIHeight < 0)
{
args.UIHeight = 0;
}
}
else
{
args.UIHeight = param.Size.Height;
}
if ((param.Anchor & leftRightAnchor) == AnchorStyles.None)
{
args.left = -(args.UIWidth / 2
+ (viewportWidth - args.UIWidth)
* ((double)param.Margin.Left / (double)(param.Margin.Left + param.Margin.Right)));
}
else if ((param.Anchor & leftRightAnchor) == AnchorStyles.Left)
{
args.left = -(args.UIWidth / 2 + param.Margin.Left);
}
else if ((param.Anchor & leftRightAnchor) == AnchorStyles.Right)
{
args.left = -(viewportWidth - args.UIWidth / 2 - param.Margin.Right);
}
else // if ((Anchor & leftRightAnchor) == leftRightAnchor)
{
args.left = -(args.UIWidth / 2 + param.Margin.Left);
}
if ((param.Anchor & topBottomAnchor) == AnchorStyles.None)
{
args.bottom = -viewportHeight / 2;
args.bottom = -(args.UIHeight / 2
+ (viewportHeight - args.UIHeight)
* ((double)param.Margin.Bottom / (double)(param.Margin.Bottom + param.Margin.Top)));
}
else if ((param.Anchor & topBottomAnchor) == AnchorStyles.Bottom)
{
args.bottom = -(args.UIHeight / 2 + param.Margin.Bottom);
}
else if ((param.Anchor & topBottomAnchor) == AnchorStyles.Top)
{
args.bottom = -(viewportHeight - args.UIHeight / 2 - param.Margin.Top);
}
else // if ((Anchor & topBottomAnchor) == topBottomAnchor)
{
args.bottom = -(args.UIHeight / 2 + param.Margin.Bottom);
}
}