surface.cs

using System;
using System.Drawing;
using System.Drawing.Imaging;
using OpenTK.Graphics.OpenGL;

namespace Template
{
	public class Surface
	{
		public int width, height;
		public int[] pixels;
		static bool fontReady = false;
		static Surface font;
		static int[] fontRedir;
		// surface constructor
		public Surface( int w, int h )
		{
			width = w;
			height = h;
			pixels = new int[w * h];
		}
		// surface constructor using a file
		public Surface( string fileName )
		{
			Bitmap bmp = new Bitmap( fileName );
			width = bmp.Width;
			height = bmp.Height;
			pixels = new int[width * height];
			BitmapData data = bmp.LockBits( new Rectangle( 0, 0, width, height ), ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb );
			IntPtr ptr = data.Scan0;
			System.Runtime.InteropServices.Marshal.Copy( data.Scan0, pixels, 0, width * height );
			bmp.UnlockBits( data );
		}
		// create an OpenGL texture
		public int GenTexture()
		{
			int id = GL.GenTexture();
			GL.BindTexture( TextureTarget.Texture2D, id );
			GL.TexParameter( TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear );
			GL.TexParameter( TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear );
			GL.TexImage2D( TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, width, height, 0, OpenTK.Graphics.OpenGL.PixelFormat.Bgra, PixelType.UnsignedByte, pixels );
			return id;
		}
		// clear the surface
		public void Clear( int c )
		{
			for( int s = width * height, p = 0; p < s; p++ ) pixels[p] = c;
		}
		// copy the surface to another surface
		public void CopyTo( Surface target, int x = 0, int y = 0 )
		{
			int src = 0;
			int dst = 0;
			int srcwidth = width;
			int srcheight = height;
			int dstwidth = target.width;
			int dstheight = target.height;
			if( (srcwidth + x) > dstwidth ) srcwidth = dstwidth - x;
			if( (srcheight + y) > dstheight ) srcheight = dstheight - y;
			if( x < 0 )
			{
				src -= x;
				srcwidth += x;
				x = 0;
			}
			if( y < 0 )
			{
				src -= y * width;
				srcheight += y;
				y = 0;
			}
			if( (srcwidth > 0) && (srcheight > 0) )
			{
				dst += x + dstwidth * y;
				for( int v = 0; v < srcheight; v++ )
				{
					for( int u = 0; u < srcwidth; u++ ) target.pixels[dst + u] = pixels[src + u];
					dst += dstwidth;
					src += width;
				}
			}
		}
		// draw a rectangle
		public void Box( int x1, int y1, int x2, int y2, int c )
		{
			int dest = y1 * width;
			for( int y = y1; y <= y2; y++, dest += width )
			{
				pixels[dest + x1] = c;
				pixels[dest + x2] = c;
			}
			int dest1 = y1 * width;
			int dest2 = y2 * width;
			for( int x = x1; x <= x2; x++ )
			{
				pixels[dest1 + x] = c;
				pixels[dest2 + x] = c;
			}
		}
		// draw a solid bar
		public void Bar( int x1, int y1, int x2, int y2, int c )
		{
			int dest = y1 * width;
			for( int y = y1; y <= y2; y++, dest += width ) for( int x = x1; x <= x2; x++ )
				{
					pixels[dest + x] = c;
				}
		}
		// helper function for line clipping
		int OUTCODE( int x, int y )
		{
			int xmin = 0, ymin = 0, xmax = width - 1, ymax = height - 1;
			return (((x) < xmin) ? 1 : (((x) > xmax) ? 2 : 0)) + (((y) < ymin) ? 4 : (((y) > ymax) ? 8 : 0));
		}
		// draw a line, clipped to the window
		public void Line( int x1, int y1, int x2, int y2, int c )
		{
			int xmin = 0, ymin = 0, xmax = width - 1, ymax = height - 1;
			int c0 = OUTCODE( x1, y1 ), c1 = OUTCODE( x2, y2 );
			bool accept = false;
			while( true )
			{
				if( c0 == 0 && c1 == 0 ) { accept = true; break; }
				else if( (c0 & c1) > 0 ) break;
				else
				{
					int x = 0, y = 0;
					int co = (c0 > 0) ? c0 : c1;
					if( (co & 8) > 0 ) { x = x1 + (x2 - x1) * (ymax - y1) / (y2 - y1); y = ymax; }
					else if( (co & 4) > 0 ) { x = x1 + (x2 - x1) * (ymin - y1) / (y2 - y1); y = ymin; }
					else if( (co & 2) > 0 ) { y = y1 + (y2 - y1) * (xmax - x1) / (x2 - x1); x = xmax; }
					else if( (co & 1) > 0 ) { y = y1 + (y2 - y1) * (xmin - x1) / (x2 - x1); x = xmin; }
					if( co == c0 ) { x1 = x; y1 = y; c0 = OUTCODE( x1, y1 ); }
					else { x2 = x; y2 = y; c1 = OUTCODE( x2, y2 ); }
				}
			}
			if( !accept ) return;
			if( Math.Abs( x2 - x1 ) >= Math.Abs( y2 - y1 ) )
			{
				if( x2 < x1 ) { int h = x1; x1 = x2; x2 = h; h = y2; y2 = y1; y1 = h; }
				int l = x2 - x1;
				if( l == 0 ) return;
				int dy = ((y2 - y1) * 8192) / l;
				y1 *= 8192;
				for( int i = 0; i < l; i++ )
				{
					pixels[x1++ + (y1 / 8192) * width] = c;
					y1 += dy;
				}
			}
			else
			{
				if( y2 < y1 ) { int h = x1; x1 = x2; x2 = h; h = y2; y2 = y1; y1 = h; }
				int l = y2 - y1;
				if( l == 0 ) return;
				int dx = ((x2 - x1) * 8192) / l;
				x1 *= 8192;
				for( int i = 0; i < l; i++ )
				{
					pixels[x1 / 8192 + y1++ * width] = c;
					x1 += dx;
				}
			}
		}
		// plot a single pixel
		public void Plot( int x, int y, int c )
		{
			if( (x >= 0) && (y >= 0) && (x < width) && (y < height) )
			{
				pixels[x + y * width] = c;
			}
		}
		// print a string
		public void Print( string t, int x, int y, int c )
		{
			if( !fontReady )
			{
				font = new Surface( "../../assets/font.png" );
				string ch = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()_-+={}[];:<>,.?/\\ ";
				fontRedir = new int[256];
				for( int i = 0; i < 256; i++ ) fontRedir[i] = 0;
				for( int i = 0; i < ch.Length; i++ )
				{
					int l = (int)ch[i];
					fontRedir[l & 255] = i;
				}
				fontReady = true;
			}
			for( int i = 0; i < t.Length; i++ )
			{
				int f = fontRedir[(int)t[i] & 255];
				int dest = x + i * 12 + y * width;
				int src = f * 12;
				for( int v = 0; v < font.height; v++, src += font.width, dest += width ) for( int u = 0; u < 12; u++ )
					{
						if( (font.pixels[src + u] & 0xffffff) != 0 ) pixels[dest + u] = c;
					}
			}
		}
	}
	public class Sprite
	{
		Surface bitmap;
		static public Surface target;
		int textureID;
		// sprite constructor
		public Sprite( string fileName )
		{
			bitmap = new Surface( fileName );
			textureID = bitmap.GenTexture();
		}
		// draw a sprite with scaling
		public void Draw( float x, float y, float scale = 1.0f )
		{
			GL.BindTexture( TextureTarget.Texture2D, textureID );
			GL.Enable( EnableCap.Blend );
			GL.BlendFunc( BlendingFactor.SrcAlpha, BlendingFactor.OneMinusSrcAlpha );
			GL.Begin( PrimitiveType.Quads );
			float u1 = (x * 2 - 0.5f * scale * bitmap.width) / target.width - 1;
			float v1 = 1 - (y * 2 - 0.5f * scale * bitmap.height) / target.height;
			float u2 = ((x + 0.5f * scale * bitmap.width) * 2) / target.width - 1;
			float v2 = 1 - ((y + 0.5f * scale * bitmap.height) * 2) / target.height;
			GL.TexCoord2( 0.0f, 1.0f ); GL.Vertex2( u1, v2 );
			GL.TexCoord2( 1.0f, 1.0f ); GL.Vertex2( u2, v2 );
			GL.TexCoord2( 1.0f, 0.0f ); GL.Vertex2( u2, v1 );
			GL.TexCoord2( 0.0f, 0.0f ); GL.Vertex2( u1, v1 );
			GL.End();
			GL.Disable( EnableCap.Blend );
		}
	}
}