public static void UpdateTexture(TContext tr, Bitmap texImage)
{
Gl.glGenTextures(1, out tex);
Gl.glBindTexture(Gl.GL_TEXTURE_2D, tex);
Data = texImage.LockBits(new Rectangle(0, 0, texImage.Width, texImage.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
tr.TexImage = Data.Scan0;
Gl.glTexImage2D(Gl.GL_TEXTURE_2D, 0, Gl.GL_RGBA, texImage.Width, texImage.Height, 0, Gl.GL_BGRA, Gl.GL_UNSIGNED_BYTE, tr.TexImage);
texImage.UnlockBits(Data);
texImage.Dispose();
Gl.glTexParameteri(Gl.GL_TEXTURE_2D, Gl.GL_TEXTURE_MIN_FILTER, Gl.GL_LINEAR);
Gl.glTexParameteri(Gl.GL_TEXTURE_2D, Gl.GL_TEXTURE_MAG_FILTER, Gl.GL_LINEAR);
}
public static bool DrawTexture(TContext tr, TexCod texture)
{
tr.Texture = texture;
ComputeTileRange(tr);
// calculate tile statrting address
tr.TileAdrs.X = texture.LLx / tr.TileWidth;
tr.TileAdrs.Y = texture.LLy / tr.TileHeight;
if (TileDraw(tr))
{
return((bool)true);
}
return(false);
}
private static bool TileDraw(TContext tr)
{
// choose tile lowleft coordinate
Gl.glBindTexture(Gl.GL_TEXTURE_2D, tex);
Gl.glReadBuffer(Gl.GL_BACK);
while (tr.TileRange.LLy <= tr.TileAdrs.Y && tr.TileAdrs.Y <= tr.TileRange.TRy)
{
while (tr.TileRange.LLx <= tr.TileAdrs.X && tr.TileAdrs.X <= tr.TileRange.TRx)
{
// Console.WriteLine(tr.TileAdrs.ToString());
tr.LLTileCod.X = tr.TileAdrs.X * tr.TileWidth;
tr.LLTileCod.Y = tr.TileAdrs.Y * tr.TileHeight;
tr.TRTileCod.X = tr.LLTileCod.X + tr.TileWidth - 1;
tr.TRTileCod.Y = tr.LLTileCod.Y + tr.TileHeight - 1;
// overalpping coorfinate
tr.OverlapLL = CalOverlap(tr.LLTileCod, tr.Texture);
tr.OverlapTR = CalOverlap(tr.TRTileCod, tr.Texture);
// Console.WriteLine("overlap " + tr.OverlapLL.ToString() +"*"+ tr.OverlapTR.ToString());
// calulate texmap coordinate
CalTexMap(tr);
// Console.WriteLine(tr.TexMapCod.ToString());
// re- calculate overlap as per rendering viewport
RecalView(tr);
// Console.WriteLine("viewport " + tr.OverlapLL.ToString() + "*" + tr.OverlapTR.ToString());
TileRender(tr);
// reading into PBO genrated before
Gl.glPixelStorei(Gl.GL_PACK_ROW_LENGTH, tr.CanvWidth);
Gl.glPixelStorei(Gl.GL_PACK_SKIP_ROWS, tr.TileAdrs.Y * tr.TileHeight);
Gl.glPixelStorei(Gl.GL_PACK_SKIP_PIXELS, tr.TileAdrs.X * tr.TileWidth);
Gl.glReadPixels(0, 0, tr.TileWidth, tr.TileWidth, Gl.GL_BGRA, Gl.GL_UNSIGNED_BYTE, IntPtr.Zero);
// choose the next tile to be rendered
// shift right
tr.TileAdrs.X = tr.TileAdrs.X + 1;
}
tr.TileAdrs.X = tr.TileRange.LLx;
tr.TileAdrs.Y = tr.TileAdrs.Y + 1;
}
Gl.glBindTexture(Gl.GL_TEXTURE_2D, 0);
return((bool)true);
}
public static void TileRender(TContext tr) // render and store
{
Gl.glClearColor(0f, 0f, 0f, 0f);
Gl.glClear(Gl.GL_COLOR_BUFFER_BIT);
Gl.glViewport(0, 0, tr.TileWidth, tr.TileHeight);
Gl.glEnable(Gl.GL_TEXTURE_2D);
Gl.glBegin(Gl.GL_QUADS);
x0 = Utility.Map((float)tr.OverlapLL.X, 0f, (float)tr.TileWidth, -1f, 1f);
y0 = Utility.Map((float)tr.OverlapLL.Y, 0f, (float)tr.TileHeight, -1f, 1f);
x1 = Utility.Map((float)tr.OverlapTR.X, 0f, (float)tr.TileWidth, -1f, 1f);
y1 = Utility.Map((float)tr.OverlapTR.Y, 0f, (float)tr.TileHeight, -1f, 1f);
Gl.glTexCoord2f(tr.TexMapCod.X0, tr.TexMapCod.Y0); Gl.glVertex2f(x0, y1);
Gl.glTexCoord2f(tr.TexMapCod.X0, tr.TexMapCod.Y1); Gl.glVertex2f(x0, y0);
Gl.glTexCoord2f(tr.TexMapCod.X1, tr.TexMapCod.Y1); Gl.glVertex2f(x1, y0);
Gl.glTexCoord2f(tr.TexMapCod.X1, tr.TexMapCod.Y0); Gl.glVertex2f(x1, y1);
Gl.glEnd();
Gl.glFlush();
}
public static void Setup(TContext tr, int canvasW, int canvasH, int tileWidth, int tileHeight)
{
tr.CanvWidth = canvasW; tr.CanvHeight = canvasH;
tr.TileWidth = tileWidth; tr.TileHeight = tileHeight;
}
