LoadBSP would be nice

Thats the Q3 BSP code of my old engine:

SuperStrict

Import BRL.FileSystem
Import BRL.EndianStream
Import "Entity.bmx"
Import "Texture.bmx"

' Header
Const DDD_Q3MAP_MAGIC   : Int = $50534249 ' "IBSP"
Const DDD_Q3MAP_VERSION : Int = $2E

' Lumps
Const DDD_Q3MAP_ENTITIES    : Int = 0
Const DDD_Q3MAP_TEXTURES    : Int = 1
Const DDD_Q3MAP_PLANES      : Int = 2
Const DDD_Q3MAP_NODES       : Int = 3
Const DDD_Q3MAP_LEAFS       : Int = 4
Const DDD_Q3MAP_LEAFFACES   : Int = 5
Const DDD_Q3MAP_LEAFBRUSHES : Int = 6
Const DDD_Q3MAP_MODELS      : Int = 7
Const DDD_Q3MAP_BRUSHES     : Int = 8
Const DDD_Q3MAP_BRUSHSIDES  : Int = 9
Const DDD_Q3MAP_VERTICES    : Int = 10
Const DDD_Q3MAP_INDICES     : Int = 11
Const DDD_Q3MAP_EFFECTS     : Int = 12
Const DDD_Q3MAP_FACES       : Int = 13
Const DDD_Q3MAP_LIGHTMAPS   : Int = 14
Const DDD_Q3MAP_LIGHTVOLS   : Int = 15
Const DDD_Q3MAP_VISDATA     : Int = 16

' FaceTypes
Const DDD_Q3MAP_POLYGON : Int = 1
Const DDD_Q3MAP_PATCH   : Int = 2
Const DDD_Q3MAP_MESH    : Int = 3

Type TQ3Map Extends TEntity
	Field TextureCount  : Int
	Field LightmapCount : Int
	Field Textures      : Int[]
	Field Lightmaps     : Int[]

	Method Render(Camera:TEntity)
	End Method

	Function Load:TQ3Map(URL:Object, Gamma:Float=0.0, Tesselation:Int=4)
		Return TQ3MapLoader.Load(URL, Gamma, Tesselation)
	End Function
End Type

Type TQ3Header
	Field Magic   : Int
	Field Version : Int
	Field Lumps   : Int[17, 2]

	Method Read(Stream:TStream)
		Self.Magic   = Stream.ReadInt()
		Self.Version = Stream.ReadInt()
		Stream.Read(Self.Lumps, 136)
	End Method

	Method Check:Int()
		If (Self.Magic <> DDD_Q3MAP_MAGIC) Or ..
           (Self.Version <> DDD_Q3MAP_VERSION) Then
			Return False
		Else
			Return True
		EndIf
	End Method
End Type

Type TQ3Texture
	Field Name     : String
	Field Flags    : Int
	Field Contents : Int

	Method Read(Stream:TStream)
		Self.Name     = Stream.ReadString(64)
		Self.Flags    = Stream.ReadInt()
		Self.Contents = Stream.ReadInt()

		If Self.Name.Find("~0") <> -1 Then ..
		   Self.Name = Self.Name[0..Self.Name.Find("~0")]
	End Method

	Method GetFilename:String()
		If Self.Name = "noshader" Then
			Return ""
		ElseIf FileType(Self.Name+".jpg") = 1 Then
			Return Self.Name+".jpg"
		ElseIf FileType(Self.Name+".tga") = 1 Then
			Return Self.Name+".tga"
		Else
			If FileType(StripDir(Self.Name)+".jpg") = 1 Then
				Return StripDir(Self.Name)+".jpg"
			ElseIf FileType(StripDir(Self.Name)+".tga") = 1 Then
				Return StripDir(Self.Name)+".tga"
			Else
				Return ""
			EndIf
		EndIf
	End Method

	Method LoadGLTexture:Int()
		Local Pixmap:TPixmap, Format:Int, Width:Int, Height:Int
		Local Texture:Int

		Pixmap = LoadPixmap(Self.GetFilename())
		If Not Pixmap Then Return -1

		Select Pixmap.Format
			Case PF_RGB888
				Format = GL_RGB
			Case PF_BGR888
				Pixmap = Pixmap.Convert(PF_RGB888)
				Format = GL_RGB
			Case PF_RGBA8888
				Format = GL_RGBA
			Case PF_BGRA8888
				Pixmap = Pixmap.Convert(PF_RGBA8888)
				Format = GL_RGBA
		End Select

		Width  = Pixmap.Width
		Height = Pixmap.Height
		TTexture.AdjustTexSize(Width, Height)
		If (Width <> Pixmap.Width) Or (Height <> Pixmap.Height) Then ..
		   Pixmap = ResizePixmap(Pixmap, Width, Height)

		glGenTextures(1, Varptr(Texture))
		glBindTexture(GL_TEXTURE_2D, Texture)
		gluBuild2DMipmaps(GL_TEXTURE_2D, Format, Width, Height, Format, ..
		                  GL_UNSIGNED_BYTE, Pixmap.Pixels)
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR)
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)

		Return Texture
	End Method
End Type

Type TQ3Lightmap
	Field Pixels : Byte[49152]

	Method Read(Stream:TStream)
		Stream.Read(Self.Pixels, 49152)
	End Method

	Method MakeGLTexture:Int(Gamma:Float=0.0)
		Local Index:Int, Bias:Int, Pixel:Int, Texture:Int

		If Gamma <> 0.0 Then
			For Index = 0 Until 49152
				Bias = Gamma*255.0
				Pixel = Self.Pixels[Index]

				Pixel :+ Bias
				If Pixel < 0   Then Pixel = 0
				If Pixel > 255 Then Pixel = 255

				Self.Pixels[Index] = Pixel
			Next
		EndIf

		glGenTextures(1, Varptr(Texture))
		glBindTexture(GL_TEXTURE_2D, Texture)
		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 128, 128, 0, GL_RGB, ..
		             GL_UNSIGNED_BYTE, Self.Pixels)
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)

		glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE)
		glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_MODULATE)
		glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB, GL_PREVIOUS)
		glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_RGB, GL_TEXTURE)
		glTexEnvf(GL_TEXTURE_ENV, GL_RGB_SCALE, 2.0)

		Return Texture
	End Method
End Type

Type TQ3BiQuadPatch
	Field ControlPoints : Float[9, 14]
	Field Vertices      : Float[,]
	Field Indices       : Int[]

	Method Tesselate(Tesselation:Int)
	End Method
End Type

Type TQ3Face
	Field TextureID      : Int
	Field Effect         : Int
	Field FaceType       : Int
	Field FirstVertex    : Int
	Field NumVertices    : Int
	Field FirstIndex     : Int
	Field NumIndices     : Int
	Field LightmapID     : Int
	Field LightmapStart  : Int[2]
	Field LightmapSize   : Int[2]
	Field LightmapOrigin : Float[3]
	Field Tangent        : Float[2, 3]
	Field Normal         : Float[3]
	Field PatchSize      : Int[2]
	Field Patches        : TQ3BiQuadPatch[,]

	Method Read(Loader:TQ3MapLoader, Tesselation:Int)
		Self.TextureID   = Loader.Stream.ReadInt()
		Self.Effect      = Loader.Stream.ReadInt()
		Self.FaceType    = Loader.Stream.ReadInt()
		Self.FirstVertex = Loader.Stream.ReadInt()
		Self.NumVertices = Loader.Stream.ReadInt()
		Self.FirstIndex  = Loader.Stream.ReadInt()
		Self.NumIndices  = Loader.Stream.ReadInt()
		Self.LightmapID  = Loader.Stream.ReadInt()

		Loader.Stream.Read(Self.LightmapStart, 8)
		Loader.Stream.Read(Self.LightmapSize, 8)

		Self.LightmapOrigin[0] =  Loader.Stream.ReadFloat()
		Self.LightmapOrigin[2] = -Loader.Stream.ReadFloat()
		Self.LightmapOrigin[1] =  Loader.Stream.ReadFloat()

		Self.Tangent[0, 0] =  Loader.Stream.ReadFloat()
		Self.Tangent[0, 2] = -Loader.Stream.ReadFloat()
		Self.Tangent[0, 1] =  Loader.Stream.ReadFloat()

		Self.Tangent[1, 0] =  Loader.Stream.ReadFloat()
		Self.Tangent[1, 2] = -Loader.Stream.ReadFloat()
		Self.Tangent[1, 1] =  Loader.Stream.ReadFloat()
		
		Loader.Stream.Read(Self.Normal, 12)
		Loader.Stream.Read(Self.PatchSize, 8)
		
		If Self.FaceType = DDD_Q3MAP_PATCH Then
		ElseIf Self.FaceType = DDD_Q3MAP_POLYGON Or ..
		       Self.FaceType = DDD_Q3MAP_MESH Then
		EndIf
	End Method
End Type

Type TQ3MapLoader
	Field Stream      : TStream
	Field Map         : TQ3Map
	Field Header      : TQ3Header
	Field Vertices    : Float[,]
	Field Indices     : Int[]
	Field Faces       : TQ3Face[]
	Field Planes      : Float[,]

	Function Load:TQ3Map(URL:Object, Gamma:Float=0.0, Tesselation:Int=4)
		Local Loader:TQ3MapLoader, OldDir:String, Count:Int, Index:Int
		Local Texture:TQ3Texture, Lightmap:TQ3LightMap

		' Check if Stream can load
		Loader = New TQ3MapLoader
		Loader.Stream = LittleEndianStream(ReadStream(URL))
		If Not Loader.Stream Then Return Null

		' Check header
		Loader.Header = New TQ3Header
		Loader.Header.Read(Loader.Stream)
		If Not Loader.Header.Check() Then
			Loader.Stream.Close()
			Return Null
		EndIf

		' New Quake3 Map
		Loader.Map = New TQ3Map

		' Change Directory for Textures
		OldDir = CurrentDir()
		If String(URL) <> "" Then ChangeDir(ExtractDir(String(URL)))

		' Load Textures
		Loader.Stream.Seek(Loader.Header.Lumps[DDD_Q3MAP_TEXTURES, 0])
		Count = Loader.Header.Lumps[DDD_Q3MAP_TEXTURES, 1]/72
		Loader.Map.TextureCount = Count
		Loader.Map.Textures = New Int[Count]
		
		Texture = New TQ3Texture
		For Index = 0 Until Count
			Texture.Read(Loader.Stream)
			Loader.Map.Textures[Index] = Texture.LoadGLTexture()
		Next

		' Load Lightmaps
		Loader.Stream.Seek(Loader.Header.Lumps[DDD_Q3MAP_LIGHTMAPS, 0])
		Count = Loader.Header.Lumps[DDD_Q3MAP_LIGHTMAPS, 1]/49152
		Loader.Map.LightmapCount = Count
		Loader.Map.Lightmaps = New Int[Count]
		
		Lightmap = New TQ3LightMap
		For Index = 0 Until Count
			Lightmap.Read(Loader.Stream)
			Loader.Map.Lightmaps[Index] = Lightmap.MakeGLTexture(Gamma)
		Next
		
		' Load Vertices
		Loader.Stream.Seek(Loader.Header.Lumps[DDD_Q3MAP_VERTICES, 0])
		Count = Loader.Header.Lumps[DDD_Q3MAP_VERTICES, 1]/44
		Loader.Vertices = New Float[Count, 14]

		For Index = 0 Until Count
			' Position
			Loader.Vertices[Index, 0] = Loader.Stream.ReadFloat()/64.0
			Loader.Vertices[Index, 2] = Loader.Stream.ReadFloat()/(-64.0)
			Loader.Vertices[Index, 1] = Loader.Stream.ReadFloat()/64.0

			' Texture UV
			Loader.Vertices[Index, 6] = Loader.Stream.ReadFloat()
			Loader.Vertices[Index, 7] = Loader.Stream.ReadFloat()
			
			' Lightmap UV
			Loader.Vertices[Index, 8] = Loader.Stream.ReadFloat()
			Loader.Vertices[Index, 9] = Loader.Stream.ReadFloat()

			' Normal
			Loader.Vertices[Index, 3] = Loader.Stream.ReadFloat()
			Loader.Vertices[Index, 5] = -Loader.Stream.ReadFloat()
			Loader.Vertices[Index, 4] = Loader.Stream.ReadFloat()
			
			' Color
			Loader.Vertices[Index, 10] = Float(Loader.Stream.ReadByte())/255.0
			Loader.Vertices[Index, 11] = Float(Loader.Stream.ReadByte())/255.0
			Loader.Vertices[Index, 12] = Float(Loader.Stream.ReadByte())/255.0
			Loader.Vertices[Index, 13] = Float(Loader.Stream.ReadByte())/255.0
		Next

		' Load Indices
		Loader.Stream.Seek(Loader.Header.Lumps[DDD_Q3MAP_INDICES, 0])
		Count = Loader.Header.Lumps[DDD_Q3MAP_INDICES, 1]/4
		Loader.Indices = New Int[Count]
		Loader.Stream.Read(Loader.Indices, Count*4)

		' Load Faces
		Loader.Stream.Seek(Loader.Header.Lumps[DDD_Q3MAP_FACES, 0])
		Count = Loader.Header.Lumps[DDD_Q3MAP_FACES, 1]/104
		Loader.Faces = New TQ3Face[Count]

		For Index = 0 Until Count
			Loader.Faces[Index] = New TQ3Face
			Loader.Faces[Index].Read(Loader, Tesselation)
		Next

		Loader.Stream.Close()
		ChangeDir(OldDir)

		Return Loader.Map
	End Function
End Type

The gamma setting in this code is wrong. Many times later I've found a ?original? code by Carmack:

//===============================================================================

static void HSVtoRGB( float h, float s, float v, float rgb[3] )
{
    int i;
    float f;
    float p, q, t;

    h *= 5;

    i = floor( h );
    f = h - i;

    p = v * ( 1 - s );
    q = v * ( 1 - s * f );
    t = v * ( 1 - s * ( 1 - f ) );

    switch ( i )
    {
    case 0:
        rgb[0] = v;
        rgb[1] = t;
        rgb[2] = p;
        break;
    case 1:
        rgb[0] = q;
        rgb[1] = v;
        rgb[2] = p;
        break;
    case 2:
        rgb[0] = p;
        rgb[1] = v;
        rgb[2] = t;
        break;
    case 3:
        rgb[0] = p;
        rgb[1] = q;
        rgb[2] = v;
        break;
    case 4:
        rgb[0] = t;
        rgb[1] = p;
        rgb[2] = v;
        break;
    case 5:
        rgb[0] = v;
        rgb[1] = p;
        rgb[2] = q;
        break;
    }
}

/*
===============
R_ColorShiftLightingBytes

===============
*/
static    void R_ColorShiftLightingBytes( byte in[4], byte out[4] ) {
    int        shift, r, g, b;

    // shift the color data based on overbright range
    shift = r_mapOverBrightBits->integer - tr.overbrightBits;

    // shift the data based on overbright range
    r = in[0] << shift;
    g = in[1] << shift;
    b = in[2] << shift;
   
    // normalize by color instead of saturating to white
    if ( ( r | g | b ) > 255 ) {
        int        max;

        max = r > g ? r : g;
        max = max > b ? max : b;
        r = r * 255 / max;
        g = g * 255 / max;
        b = b * 255 / max;
    }

    out[0] = r;
    out[1] = g;
    out[2] = b;
    out[3] = in[3];
}

/*
===============
R_LoadLightmaps

===============
*/
#define    LIGHTMAP_SIZE    128
static    void R_LoadLightmaps( lump_t *l ) {
    byte        *buf, *buf_p;
    int            len;
    MAC_STATIC byte        image[LIGHTMAP_SIZE*LIGHTMAP_SIZE*4];
    int            i, j;
    float maxIntensity = 0;
    double sumIntensity = 0;

    len = l->filelen;
    if ( !len ) {
        return;
    }
    buf = fileBase + l->fileofs;

    // we are about to upload textures
    R_SyncRenderThread();

    // create all the lightmaps
    tr.numLightmaps = len / (LIGHTMAP_SIZE * LIGHTMAP_SIZE * 3);
    if ( tr.numLightmaps == 1 ) {
        //FIXME: HACK: maps with only one lightmap turn up fullbright for some reason.
        //this avoids this, but isn't the correct solution.
        tr.numLightmaps++;
    }

    // if we are in r_vertexLight mode, we don't need the lightmaps at all
    if ( r_vertexLight->integer || glConfig.hardwareType == GLHW_PERMEDIA2 ) {
        return;
    }

    for ( i = 0 ; i < tr.numLightmaps ; i++ ) {
        // expand the 24 bit on-disk to 32 bit
        buf_p = buf + i * LIGHTMAP_SIZE*LIGHTMAP_SIZE * 3;

        if ( r_lightmap->integer == 2 )
        {    // color code by intensity as development tool    (FIXME: check range)
            for ( j = 0; j < LIGHTMAP_SIZE * LIGHTMAP_SIZE; j++ )
            {
                float r = buf_p[j*3+0];
                float g = buf_p[j*3+1];
                float b = buf_p[j*3+2];
                float intensity;
                float out[3];

                intensity = 0.33f * r + 0.685f * g + 0.063f * b;

                if ( intensity > 255 )
                    intensity = 1.0f;
                else
                    intensity /= 255.0f;

                if ( intensity > maxIntensity )
                    maxIntensity = intensity;

                HSVtoRGB( intensity, 1.00, 0.50, out );

                image[j*4+0] = out[0] * 255;
                image[j*4+1] = out[1] * 255;
                image[j*4+2] = out[2] * 255;
                image[j*4+3] = 255;

                sumIntensity += intensity;
            }
        } else {
            for ( j = 0 ; j < LIGHTMAP_SIZE * LIGHTMAP_SIZE; j++ ) {
                R_ColorShiftLightingBytes( &buf_p[j*3], &image[j*4] );
                image[j*4+3] = 255;
            }
        }
        tr.lightmaps[i] = R_CreateImage( va("*lightmap%d",i), image,
            LIGHTMAP_SIZE, LIGHTMAP_SIZE, qfalse, qfalse, GL_CLAMP );
    }

    if ( r_lightmap->integer == 2 )    {
        ri.Printf( PRINT_ALL, "Brightest lightmap value: %d\n", ( int ) ( maxIntensity * 255 ) );
    }
}

So the original gamma correction is based on the HSV Lighting Model.

Q3_POLYGON and Q3_MESH faces are easy bring in to MiniB3D Surfaces. Q3_PATCHES are Bi Quad Patches that needs a tesselation by giving control points. Blitz3D have a fixed tesselation value, but I hope, MiniB3D will have an extra parameter like LoadBSP:TQ3Map(URL:OBject, Gamma:Float=0.0, Tesselation:Int=4).

The challenge to render Q3 Maps is the BSP algorithm. You have to detect in what leaf is the camera(using point to plane computions) and render only these faces, that is joined with the VIS Data for a leaf.

I don't know if there is a clever way to use TMesh and TSurface or using a slim version for rendering to bring up more render performence(becouse, there is no shader, brush, cubemap and etc. stuff needed)

cu olli