I am trying to start a Pie Chart at an angle PI.
I saw some documentation on it but it always start at PI/2. What am I doing wrong?
"var grafica = new RGraph.SVG.Pie({
id: 'cc',
data: data,
start: RGraph.PI,
options: {
linewidth: 0,
donut:true,
donutWidth:40;})
If by "Pi/2" you mean that you want it to start at the east axis, then
there's no option for the SVG Pie chart to alter the start point so
you'll need to update the source code. Fortunately it's quite easy.
In the RGraph.svg.pie.js file you can find this:
this.drawSegments = function (opt)
{
var start = 0,
end = 0,
angle = 0,
sum = RGraph.SVG.arraySum(this.data),
segment = 0;
You just need to update the angle so that it looks like this:
this.drawSegments = function (opt)
{
var start = 0,
end = 0,
angle = 1.57,
sum = RGraph.SVG.arraySum(this.data),
segment = 0;
(angles are measured in radians - not degrees).
Related
i do have the following Code:
private static void AddElements(Canvas canvas)
{
double canvasHeight = canvas.Height;
double canvasWidth = canvas.Width;
double y0 = canvasHeight / 2;
double x0 = canvasWidth / 2;
// Defining the new Coordinate-Point (0,0) to mid auf Canvas
TranslateTransform tt = new TranslateTransform(x0, y0);
Line line1 = new Line();
line1.X1 = -350;
line1.Y1 = 0;
line1.X2 = 350;
line1.Y2 = 0;
line1.Stroke = Brushes.Black;
line1.StrokeThickness = 2.0;
line1.RenderTransform = tt;
canvas.Children.Add(line1);
Line line2 = new Line();
line2.X1 = 0;
line2.Y1 = -350;
line2.X2 = 0;
line2.Y2 = 350;
line2.Stroke = Brushes.Black;
line2.StrokeThickness = 2.0;
line2.RenderTransform = tt;
canvas.Children.Add(line2);
Label lblN = new Label();
lblN.Width = 50;
lblN.Background = Brushes.Red;
lblN.Margin = new System.Windows.Thickness(0, -350, 0, 0);
lblN.Content = $"N";
lblN.HorizontalContentAlignment = System.Windows.HorizontalAlignment.Center;
lblN.VerticalContentAlignment = System.Windows.VerticalAlignment.Center;
lblN.RenderTransform = tt;
lblN.Padding = new System.Windows.Thickness(0);
lblN.BorderBrush = Brushes.Black;
lblN.BorderThickness = new System.Windows.Thickness(2.0);
lblN.RenderTransform = tt;
canvas.Children.Add(lblN);
Label lblS = new Label();
lblS.Width = 50;
lblS.Background = Brushes.Red;
lblS.Margin = new System.Windows.Thickness(0, 350, 0, 0);
lblS.Content = $"S";
lblS.HorizontalContentAlignment = System.Windows.HorizontalAlignment.Center;
lblS.VerticalContentAlignment = System.Windows.VerticalAlignment.Center;
lblS.RenderTransform = tt;
lblS.Padding = new System.Windows.Thickness(0);
lblS.BorderBrush = Brushes.Black;
lblS.BorderThickness = new System.Windows.Thickness(2.0);
lblS.RenderTransform = tt;
canvas.Children.Add(lblS);
}
this method is called on an Menu-Eventhandler and it shows an coordinate system with (0,0) in the mid of the canvas. It should show a label with "N" at the top and a label with "S" at the bottom.
But i shows the attached image
Does anyone know, why lblN looks different than lblS ?
best regards
Volkhard
=============
if i set the height of both Label-Objects to 15
lblN.Height=15
:
lblS.Height=15
i get the following:
i expected the lblN to be more upper on the y-coordinate.
What's causing it
Through a bit of testing, I can definitely say that it's the lblN.Margin = new System.Windows.Thickness(0, -350, 0, 0); that's causing the problem. Apparently, when you give a Label a negative margin like that, it will move upwards only as far is it's Height, and then it will start expanding instead of just continuing to move. So you end up with a Label that's 350 tall. We could try to figure out why that is, but really, that would be missing the point.
Admittedly, I don't have any direct documentation to back up the following statement this, but from years of experience in WPF I feel I can say:
Margin is intended to be used to give space between elements in a dynamic layout, not to give an element an absolute position.
This behavior of the Label seems to strengthen the idea that using Margin in this way was not something that was planed for by the designers.
What you should do instead
Canvas has tools for giving an element a set position, yet nowhere do you use Canvas's SetLeft, SetTop, SetRight, or SetBottom. Take a look at the example on MSDN. You shouldn't need to use a TranslateTransform or set Margin at all. Instead, you should calculate where you want the element to be and use one of the above four listed methods to assign that position.
Extra Tip
Don't use canvas.Height and canvas.Width, use canvas.ActualHeight and canvas.ActualWidth instead. The first pair only work if you are explicitly setting the size of the Canvas (which it seems you are). But in a senario where the Canvas is dynamically sized, the first pair will be NaN. The second pair always return the actual size that the Canvas is.
This doesn't make a difference in your current use case, but it might later on. If you're doing calculations based on the actual size of an element (as opposed to the size you might want it to be), always use ActualHeight and ActualWidth.
Original question
Basically, I have two bitmaps, and I want to put one behind the other, scaled down to half its size.
Both are centered, and are of the same resolution.
The catch is that I want to put more than one bitmap on this back layer eventually, and want the scaling to apply to the whole layer and not just the individual bitmap.
My thought is I would use a memory DC for the back layer, capture its contents into a bitmap of its own and use StretchBlt to place it in my main dc
The code I have right now doesn't work, and I can't make sense of it, let alone find anyone who had done this before for direction.
My variables at the moment are as follows
hBitmap - back bitmap
hFiller - front bitmap
hdc - main DC
ldc - back DC(made with CreateCompatibleDC(hdc);)
resh - width of hdc
resv - height of hdc
note that my viewport origin is set to the center
--this part above is solved, with the one major issue being that it does not keep the back layers...
Revised Question
Here's my code. Everything works as intended except for the fact that the layers do not properly stack. They seem to erase what is underneath or fill it with black.
For the record this is a direct copy of my code. I explain sections of it but there is nothing missing between the code blocks.
case WM_TIMER:
{
switch(wParam)
{
case FRAME:
If any position or rotation values have changed, the following section of code clears the screen and prepares it to be rewritten
if(reload == TRUE){
tdc = CreateCompatibleDC(hdc);
oldFiller = SelectObject(tdc,hFiller);
GetObject(hFiller, sizeof(filler), &filler);
StretchBlt(hdc, 0-(resh/2), 0-(resv/2), resh, resv, tdc, 0, 0, 1, 1, SRCCOPY);
SelectObject(tdc,oldFiller);
DeleteDC(tdc);
if(turn == TRUE){
xForm.eM11 = (FLOAT) cos(r/angleratio);
xForm.eM12 = (FLOAT) sin(r/angleratio);
xForm.eM21 = (FLOAT) -sin(r/angleratio);
xForm.eM22 = (FLOAT) cos(r/angleratio);
xForm.eDx = (FLOAT) 0.0;
xForm.eDy = (FLOAT) 0.0;
SetWorldTransform(hdc, &xForm);
}
This is the part that only partially works. At a distance of 80 my scale value will make my bitmap 1 pixel by 1 pixel, so I consider this my "draw distance"
It scales properly, but the layers do not stack, as I mentioned above
for(int i=80;i>1;i--){
tdc = CreateCompatibleDC(hdc);
tbm = CreateCompatibleBitmap(hdc, resh, resv);
SelectObject(tdc, tbm);
BitBlt(tdc, 0-(resh/2), 0-(resv/2), resh, resv,hdc,0,0,SRCCOPY);
//drawing code goes in here
ldc = CreateCompatibleDC(hdc);
oldBitmap = SelectObject(ldc,hBitmap);
StretchBlt(tdc,(int)(angleratio*atan((double)128/(double)i)),0,(int)(angleratio*atan((double)128/(double)i)),(int)(angleratio*atan((double)128/(double)i)),ldc,0,0,128,128,SRCCOPY);
SelectObject(ldc,oldBitmap);
DeleteDC(ldc);
BitBlt(hdc, 0, 0, resh, resv, tdc, 0, 0, SRCCOPY);
DeleteObject(tbm);
DeleteDC(tdc);
}
reload = FALSE;
}
This section below just checks for keyboard input which changes the position or rotation of the "camera"
This part works fine and can be ignored
if(GetKeyboardState(NULL)==TRUE){
reload = TRUE;
if(GetKeyState(VK_UP)<0){
fb--;
}
if(GetKeyState(VK_DOWN)<0){
fb++;
}
if(GetKeyState(VK_RIGHT)<0){
lr--;
}
if(GetKeyState(VK_LEFT)<0){
lr++;
}
if(GetKeyState(0x57)<0){
p++;
}
if(GetKeyState(0x53)<0){
p--;
}
}
break;
}
}
break;
After Applying a rotation or a translation matrix on the vertex array, the vertex buffer is not updated
So how can i get the position of vertices after applying the matrix?
here's the onDrawFrame() function
public void onDrawFrame(GL10 gl) {
PositionHandle = GLES20.glGetAttribLocation(Program,"vPosition");
MatrixHandle = GLES20.glGetUniformLocation(Program,"uMVPMatrix");
ColorHandle = GLES20.glGetUniformLocation(Program,"vColor");
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT|GLES20.GL_DEPTH_BUFFER_BIT );
Matrix.rotateM(RotationMatrix,0,-90f,1,0,0);
Matrix.multiplyMM(vPMatrix,0,projectionMatrix,0,viewMatrix,0);
Matrix.multiplyMM(vPMatrix,0,vPMatrix,0,RotationMatrix,0);
GLES20.glUniformMatrix4fv(MatrixHandle, 1, false, vPMatrix, 0);
GLES20.glUseProgram(Program);
GLES20.glEnableVertexAttribArray(PositionHandle);
GLES20.glVertexAttribPointer(PositionHandle,3,GLES20.GL_FLOAT,false,0,vertexbuffer);
GLES20.glUniform4fv(ColorHandle,1,color,1);
GLES20.glDrawArrays(GLES20.GL_TRIANGLES,0,6);
GLES20.glDisableVertexAttribArray(PositionHandle);
}
The GPU doesn't normally write back transformed results anywhere the application can use them. It's possible in ES 3.0 with transform feedback, BUT it's very expensive.
For touch event "hit" testing, you generally don't want to use the raw geometry. Generally use some simple proxy geometry, which can be transformed in software on the CPU.
Maybe you should try this:
private float[] modelViewMatrix = new float[16];
...
Matrix.rotateM(RotationMatrix, 0, -90f, 1, 0, 0);
Matrix.multiplyMM(modelViewMatrix, 0, viewMatrix, 0, RotationMatrix, 0);
Matrix.multiplyMM(vpMatrix, 0, projectionMatrix, 0, modelViewMatrix, 0);
You can use the vertex movement calculations in the CPU, and then use the GLU.gluProject() function to convert the coordinates of the vertex of the object in pixels of the screen. This data can be used when working with touch events.
private var view: IntArray = intArrayOf(0, 0, widthScreen, heightScreen)
...
GLU.gluProject(modelX, modelY, modelZ, mvMatrix, 0,
projectionMatrix, 0, view, 0,
coordinatesWindow, 0)
...
// coordinates in pixels of the screen
val x = coordinatesWindow[0]
val y = coordinatesWindow[1]
Am using SharpDX on DirectX 9 to draw a line.
Line is drawn correctly with the following code.
Vector3 startPoint= ...
Vector3 endPoint = ...
Vector3[] data = new Vector3[] { startPoint, endPoint };
device.DrawUserPrimitives<Vector3>(PrimitiveType.LineList, 1, data);
Question 1: How do we set the width of line?
Question 2: If a graphics card is used, then line width is less.
if there is no graphics card, a thicker line has been drawn.
Answer to Question 1
Using Line class, we can set the width of line.
Matrix worldViewProjection = worldMatrix * viewMatrix * projectionMatrix;
Line line = new Line(device);
line.Width = 2;
ColorBGRA lineColor = new ColorBGRA(255, 0, 0, 255);
line.Begin();
line.DrawTransform(new Vector3[] { anchorPoint, cursorPoint }, worldViewProjection, lineColor);
line.End();
Question 2 is still unanswered.
SOLVED: I'm not really sure how though... thanks for all your help guys.
I tried glDisable(GL_CULL_FACE); but the mesh is still not visible.
Basically I'm trying to draw a mesh (made from verts, normals, and texture coords) in OpenGL, using a display list. The mesh is on .obj format (exported from 3ds max 2013)
The problem is that the mesh is not visible.
To draw the display list I'm just using glCallLists (list, 1);
I have verified that I can draw things to the screen by drawing a point in the center of the screen and that works fine.
Could it be possible that the camera is positioned inside the mesh? If so is there an OpenGL state that I could enable to allow me to see the inside of a set of verts?
I know that the data I have is all valid, verified by printing each vert, normal and texture coord to a file before adding it to the display list, it looks valid.
I have dont no glTranslatef or anything like that, my projection matrix is setup like this:
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
gluPerspective (45.0, (float)1024/(float)768, -9999, 9999);
glMatrixMode (GL_MODELVIEW);
glLoadIdentity ();
If you want to have a look at the .obj file, here it is: http://pastebin.com/PpG3vG5e
This is how I create the display list:
list = glGenLists (1);
glNewList (list, GL_COMPILE);
glBegin (GL_TRIANGLES);
for (i = 0; i < data.face_count; i++)
{
// first vert
normal[0][0] = (float)data.vertex_normal_list[data.face_list[i]->normal_index[0]]->e[0];
normal[0][1] = (float)data.vertex_normal_list[data.face_list[i]->normal_index[0]]->e[1];
normal[0][2] = (float)data.vertex_normal_list[data.face_list[i]->normal_index[0]]->e[2];
tex[0][0] = (float)data.vertex_texture_list[data.face_list[i]->texture_index[0]]->e[0];
tex[0][1] = (float)data.vertex_texture_list[data.face_list[i]->texture_index[0]]->e[1];
tex[0][2] = (float)data.vertex_texture_list[data.face_list[i]->texture_index[0]]->e[2];
vert[0][0] = (float)data.vertex_list[data.face_list[i]->vertex_index[0]]->e[0];
vert[0][1] = (float)data.vertex_list[data.face_list[i]->vertex_index[0]]->e[1];
vert[0][2] = (float)data.vertex_list[data.face_list[i]->vertex_index[0]]->e[2];
// second vert
normal[1][0] = (float)data.vertex_normal_list[data.face_list[i]->normal_index[1]]->e[0];
normal[1][1] = (float)data.vertex_normal_list[data.face_list[i]->normal_index[1]]->e[1];
normal[1][2] = (float)data.vertex_normal_list[data.face_list[i]->normal_index[1]]->e[2];
tex[1][0] = (float)data.vertex_texture_list[data.face_list[i]->texture_index[1]]->e[0];
tex[1][1] = (float)data.vertex_texture_list[data.face_list[i]->texture_index[1]]->e[1];
tex[1][2] = (float)data.vertex_texture_list[data.face_list[i]->texture_index[1]]->e[2];
vert[1][0] = (float)data.vertex_list[data.face_list[i]->vertex_index[1]]->e[0];
vert[1][1] = (float)data.vertex_list[data.face_list[i]->vertex_index[1]]->e[1];
vert[1][2] = (float)data.vertex_list[data.face_list[i]->vertex_index[1]]->e[2];
// third vert
normal[2][0] = (float)data.vertex_normal_list[data.face_list[i]->normal_index[2]]->e[0];
normal[2][1] = (float)data.vertex_normal_list[data.face_list[i]->normal_index[2]]->e[1];
normal[2][2] = (float)data.vertex_normal_list[data.face_list[i]->normal_index[2]]->e[2];
tex[2][0] = (float)data.vertex_texture_list[data.face_list[i]->texture_index[2]]->e[0];
tex[2][1] = (float)data.vertex_texture_list[data.face_list[i]->texture_index[2]]->e[1];
tex[2][2] = (float)data.vertex_texture_list[data.face_list[i]->texture_index[2]]->e[2];
vert[2][0] = (float)data.vertex_list[data.face_list[i]->vertex_index[2]]->e[0];
vert[2][1] = (float)data.vertex_list[data.face_list[i]->vertex_index[2]]->e[1];
vert[2][2] = (float)data.vertex_list[data.face_list[i]->vertex_index[2]]->e[2];
for (j = 0; j < 3; j++)
{
glNormal3f (normal[j][0], normal[j][1], normal[j][2]);
glTexCoord3f (tex[j][0], tex[j][1], tex[j][2]);
glVertex3f (vert[j][0], vert[j][1], vert[j][2]);
}
}
glEnd ();
glEndList ();
EDIT:
I've tried things like:
glTranslatef (0, 0, 5);
glCallList (mesh);
glTranslatef (0, 0, 0);
but they don't work either :(
EDIT:
#datenwolf
Here is the code I use to draw it:
Draw_Begin ();
Mdl_Draw (list, 0.0f, 0.0f, 0.0f);
Draw_End ();
This
gluPerspective (45.0, (float)1024/(float)768, -9999, 9999);
is wrong. In a perspective projection both the near and the far plane distance must be of the same sign, i.e. both positive or both negative. Also the absolute value of the near plane must be smaller than the absolute value of the far plane. And the near plane distance must be nonzero. In mathematical notation:
sgn(near) = sgn(far) ^ 0 < |near| < |far|
Usually both near and far are chosen positive. Also as a rule of thumb the near clipping plane should be chosen as fer away as possible. The far plane can be placed at infinity (exploting some of the properties of homogenous matrices), but usually is placed as close as possible to max out depth buffer resolution.