ERROR XNA Framework VertexBuffer IndexBuffer usage - c#

I am creating a game after working through a XNA 4.0 book. It will be 3D, but I am already stuck in creating the terrain...
UPDATE: Everything starting from here is an update...
Terrain Update:
public void Update(Matrix view, Matrix projection)
{
View = view;
Projection = projection;
World = Matrix.CreateTranslation(-Width / 2f, 0, Height / 2f);
}
Terrain Draw:
public void Draw(GraphicsDevice g)
{
effect.CurrentTechnique = effect.Techniques["ColoredNoShading"];
effect.Parameters["xView"].SetValue(View);
effect.Parameters["xProjection"].SetValue(Projection);
effect.Parameters["xWorld"].SetValue(World);
foreach (EffectPass pass in effect.CurrentTechnique.Passes)
{
pass.Apply();
//g.DrawUserIndexedPrimitives(PrimitiveType.TriangleList, vertices, 0, vertices.Length, indices, 0, indices.Length / 3, VertexPositionColorNormal.VertexDeclaration);
g.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, vertices.Length, 0, indices.Length / 3);
}
}
The commented line is working, in the both cases I am able to see the terrain...
The following code is to initialize Vertex and Index Buffer:
private void SetUpVertices(GraphicsDevice g)
{
float currentH;
int currentI;
vertices = new VertexPositionColorNormal[Width * Height];
for (int x = 0; x < Width; x++)
{
for (int y = 0; y < Height; y++)
{
currentH = heightData[x,y];
currentI = x + y * Width;
vertices[currentI].Position = new Vector3(x, currentH , -y);
if (currentH < minH + (maxH - minH) / 3)
vertices[currentI].Color = Color.ForestGreen;
else if (currentH < maxH - (maxH - minH) / 3)
vertices[currentI].Color = Color.LawnGreen;
else
vertices[currentI].Color = Color.White;
}
}
SetUpIndices(g);
}
private void SetUpIndices(GraphicsDevice g)
{
indices = new int[(Width - 1) * (Height - 1) * 6];
int counter = 0;
for (int y = 0; y < Height - 1; y++)
{
for (int x = 0; x < Width - 1; x++)
{
int lowerLeft = x + y * Width;
int lowerRight = (x + 1) + y * Width;
int topLeft = x + (y + 1) * Width;
int topRight = (x + 1) + (y + 1) * Width;
indices[counter++] = topLeft;
indices[counter++] = lowerRight;
indices[counter++] = lowerLeft;
indices[counter++] = topLeft;
indices[counter++] = topRight;
indices[counter++] = lowerRight;
}
}
SetUpNormals(g);
}
private void SetUpNormals(GraphicsDevice g)
{
for (int i = 0; i < vertices.Length; i++)
{
vertices[i].Normal = Vector3.Zero;
}
int[] index = new int[3];
Vector3 s1, s2, n;
for (int i = 0; i < vertices.Length / 3; i++)
{
for (int y = 0; y < 3; y++)
index[y] = indices[i * 3 + y];
s1 = vertices[index[0]].Position - vertices[index[2]].Position;
s2 = vertices[index[0]].Position - vertices[index[1]].Position;
n = Vector3.Cross(s1, s2);
for (int y = 0; y < 3; y++)
{
vertices[index[y]].Normal += n;
vertices[index[y]].Normal.Normalize();
}
}
FillBuffers(g);
}
private void FillBuffers(GraphicsDevice g)
{
VertexBuffer = new VertexBuffer(g, VertexPositionColorNormal.VertexDeclaration, vertices.Length, BufferUsage.WriteOnly);
VertexBuffer.SetData(vertices);
IndexBuffer = new IndexBuffer(g, typeof(int), indices.Length, BufferUsage.WriteOnly);
IndexBuffer.SetData(indices);
g.Indices = IndexBuffer;
g.SetVertexBuffer(VertexBuffer);
}
I don't think, that there is a mistake, because it is working with the other line. Might there be an error with the .fx file I am using. If you think so, I am going to switch to BasicEffects...
(You might notice, that the code is from http://www.riemers.net/eng/Tutorials/XNA/Csharp/series1.php )
Thanks for your help...
Yours,
Florian

(Answer to original revision of the question.)
You're not setting your vertex buffer and index buffer onto the graphics device. These two lines of code (untested) should do what you need:
g.GraphicsDevice.Indices = indexBuffer;
g.GraphicsDevice.SetVertexBuffer(vertexBuffer);
Place them just after you set the parameters on your effect (ef), before the loop.
The vertex buffer provides the vertex declaration that the exception message is asking for.
Edit after question update: In your new version you're setting the vertex and index buffers - but it's in the wrong place. You need to set them onto the graphics device each frame. Your code would only work if nothing changes them after you set them in FillBuffers. But I'm guessing that stuff is being drawn outside your class's Draw method?
If that something else is a SpriteBatch, even it works using vertex buffers and index buffers. So it will reset your settings. (It's worth adding that it also sets render states - in which case you might need to see this article.)

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How to properly divide a task of editing bitmap for parallel processing for filter

I'm currently in the development phase of a photoconverter program and in the process of developing a blur filter. At the initial stages of prototyping this feature, i devised a algorithm in which I had an accumulator for each color channel and add all the pixels in a radius of the target pixel. Afterwards the program would divide the accum by the amount of pixels read(not counting those offscreen). At first I thought this would be fine but when it started to work, I had the problem of this filter taking an hour to render with this being the result at the lowest setting. So I opted to utilize parallel processing in C# to make this process much easier and faster to run. With the boost of speed came the cost of the image becoming very glitched out. Here's the image before, and Here's the image afterwards
This is the code I wrote for the filter
public static DirectBitmap NewBlur (DirectBitmap image, int radius)
{
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And here's the method for each section of the image to be blurred.
public static void BlurSection(byte[] buffer, Rectangle blurSector, Rectangle bitmaprect, int radius, int width, int height, int depth)
{
int[] Accum = new int[4];
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{
for (int y = blurSector.Y; y < blurSector.Height + blurSector.Y; y++)
{
Accum[0] = 0;
Accum[1] = 0;
Accum[2] = 0;
Accum[3] = 0;
for (int i = -radius; i <= radius; i++)
{
for (int j = -radius; j <= radius; j++)
{
var offset = 0;
offset = (((y+j) * width) + (x+i)) * depth;
if (bitmaprect.Contains(new Point(x + i, y + j))){
Accum[0] += buffer[offset + 0];
Accum[1] += buffer[offset + 1];
Accum[2] += buffer[offset + 2];
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Accum[0] = Accum[0] / Accum[3];
if (Accum[0] > 255)
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Accum[0] = 255;
}
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if (Accum[1] > 255)
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Accum[1] = 255;
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if (Accum[2] > 255)
{
Accum[2] = 255;
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buffer[newoffset + 0] = (byte)Accum[0];
buffer[newoffset + 1] = (byte)Accum[1];
buffer[newoffset + 2] = (byte)Accum[2];
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}
It's also worth noting that I'm using a Bitmap class to make access to pixel data much easier, the "DirectBitmap" you can find here: https://stackoverflow.com/a/34801225/15473435. Is there anything that I'm missing or not aware of that's causing this algorithm not to function?

Adding multiple elements to a single line of a List

Hi I am trying to add sets of coordinates to a single line of a List (so x, y as a single list line). I am currently generating the x and y coordinates as I break up an image and display the chunks in a grid. I am hitting a brick wall in being able to add both x and y to the same List line. Here is the code I have so far -
float sf = 1f;
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tileRect.X = x;
tileRect.Y = y;
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I found out how to do what I was trying to in the question. The first thing that I did was change my - private List<int> coordinates; - to a tuple list like this - List<Tuple<int, int>> coordinates; - This then allowed me to add my x and y elements to a new list by using the - coordinates.Add(new Tuple<int, int>(x,y)); - tuple functionality. Making this change has allowed me to add my generated coordinate pairs to my list.

Trimming Bitmap Causes Cutting of Text at Bottom

I'm using the following code to remove whitespace around an image.
static Bitmap TrimBitmap(Bitmap source)
{
Rectangle srcRect = default(Rectangle);
BitmapData data = null;
try
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Marshal.Copy(data.Scan0, buffer, 0, buffer.Length);
int xMin = int.MaxValue,
xMax = int.MinValue,
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yMax = int.MinValue;
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byte alpha = buffer[y * data.Stride + 4 * x + 3];
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if (stop)
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// Image is empty...
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I'm trying to trim a Bitmap with Text Drawn on it.The Proper Image should look like this after trimming
But after trimming i get the following result ..the bottom portion clipped off
What i'm i doing wrong? Please advice..
This is actually a problem with Rectangle.FromLTRB !
Looking closer at the images you will find that you have actually lost only one row of pixels. (The strong magnification had me fooled for a while..)
The algorithm to determine the Height (and Width) of the rectangle is basically right, but off by one.
If you use this
srcRect = Rectangle.FromLTRB(xMin, yMin, xMax + 1 , yMax + 1);
or this:
srcRect = new Rectangle(xMin, yMin, xMax - xMin + 1 , yMax - yMin + 1);
it should work.
You can test with pen and paper: Say: 1st pixel row with a color = 4, first from bottom on a 10 pixel square: 8, that makes 5 not 4 net data: 4,5,6,7,8.
Do note that this issue is inherent in FromLTRB:
Rectangle myRectangle = Rectangle.FromLTRB(0, 0, 10, 10);
..results in a Rectangle with Height=10 even though 0..10 should cover 11 pixels rows! So the Right-Bottom coordinate is actually excluded from the result!!
I think the whole issue with rectangles being off by one stems from legacy ways to use a Pen with its alignment. When using the same rectangles to fill with a Brush all works as expected.

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This is not entirely my code this is someone elses that i have tried to build on apparently it worked for the person for drawing one layer. This is the original code:
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I'm trying to add texture coordinates to each of the vertices so that a grass texture is added to each triangle. The code I have stretches the texture across the entire area which works but doesn't scale up very well. How do I correctly add (0,0), (0,1), (1,1), etc to the vertices?
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private void SetUpVertices()
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vertices = new VertexPositionNormalTexture[terrainWidth * terrainHeight];
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{
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int topRight = (x + 1) + (y + 1) * terrainWidth;
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indices[counter++] = (short)lowerLeft;
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Just specify
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