Changeset 182

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Timestamp:
05/25/10 16:49:56 (2 years ago)
Author:
JoeCoder
Message:

Updated TerrainNode? interface for further discussion. There's no implementation yet.

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  • trunk/src/yage/scene/terrain.d

    r181 r182  
    2323     
    2424    protected Geometry[][] mipmaps; 
    25      
    26     this() 
    27     { 
    28     } 
    29      
    30     /** 
    31      * Sets the shape of the terrain. 
    32      * Params: 
    33      *     heightMap = A grayscale image used as the heightmap of the Terrain. 
    34      *     func = A function used to generate the heightmap of the terrain.  It's given x and y values between 0 and 1 
    35      *         and it returns a 3d coordinate for that part of the Terrain grid.  The heightMap image values are then 
    36      *         used to displace the values generated by this function. 
    37      *         Both the heightMap and func parameters are optional. 
    38      *     resolution = The number of points in the x and y directions that make up the terrain grid. 
    39      *     size = The x, y, and z dimentions of the generated terrain. */ 
    40     void setGeometry(T)(Image2!(T, 1) heightMap=null, Vec3f delegate(float x, float y) func=null, Vec2f resolution=Vec2f(256), Vec3f size=Vec3f(1)) 
    41     { 
    42         // Mipmaps will be laid out something like this. 
    43         mipmaps.length = 3; // I wonder how many levels we should generate? 
    44         mipmaps[0].length = 1; // A single 64x64 block 
    45         mipmaps[1].length = 4; // Four 64x64 blocks, etc. 
    46         mipmaps[2].length = 16; 
    47          
    48         assert(image || func); 
    49      
    50         /// TODO 
    51     } 
    52      
    53      
    54     /** 
    55      * Set the Textures used for rendering the terrain. 
    56      * Params: 
     25 
     26    /** 
     27     * Provide a class that sets the shape and textures of the terrain. 
     28     * Params: 
     29     *     generator = Instance of TerrainGenerator. 
    5730     *     textures = Textures to use on the terrain.  The texture's transformation matrix can be scaled to allow 
    5831     *         textures to repeat.  For example, a scale of (1/16, 1/16, 1) will repeat the texture 16 times 
    5932     *         in the x and y directions. 
    60      *         Internally, multitexturing is used to render the terrain in as few passes as necessary. 
    61      *     blending = Array of grayscale images the same length as textures which determines the amount 
    62      *         to show each texture at each point in the terrain. 
    63      *     lightmap = If specified, this Texture will be used as a lightmap and the Terrain's materials  
    64      *         will have lighting disabled. 
    65      */ 
    66     void setTextures(T)(Texture[] textures, Image2!(T, 1)[] blending, Texture* lightmap=null) 
    67     {   assert(textures.length==blending.length); 
    68      
     33     *     min = The minimum x and y value of the range of coordinates passed to generator's getPoint() function. 
     34     *     max = The maximum x and y value of the range of coordinates passed to generator's getPoint() function.  
     35     *     resolution = The number of points (grid resolution) in the x and y directions passed  
     36     *         to generator's getPoint() function. */ 
     37    this(TerrainGenerator generator, Texture[] textures, Vec2f min=Vec2f(-128), Vec2f max=Vec2f(127), Vec2f resolution=Vec2f(256)) 
     38    { 
    6939        /// TODO 
    70         // Query Probe.feature(MAX_TEXTURE_UNITS) to determine how many MaterialPasses to generate. 
    71     } 
    72      
    73     void setChildren(T)(Geometry[] geometry, Image!(T, 1)[] maps, Vec2f[] sizes) 
    74     {   assert(geometry.length == maps.length); 
    75      
    76          
     40        // Mipmaps could be laid out something like this. 
     41        mipmaps.length = 3; // I wonder how many levels we should generate? 
     42        mipmaps[0].length = 1; // A single 64x64 block.  Is 64x64 an optimal block size? 
     43        mipmaps[1].length = 4; // Four 64x64 blocks, etc. 
     44        mipmaps[2].length = 16; 
    7745    } 
    7846     
    …… 
    9159        // This Geometry can be passed directly to the render system. 
    9260        // We should probably generate geometry lazily--this will allow for ginormous terrains too big to fit in memory. 
    93         // And also free mipmaps that  
     61        // And also free mipmaps that haven't been used in a while--a complete paging system. 
    9462         
    9563        return null; 
    9664    } 
    97      
    98      
    99     /** 
    100      * Load geometry from Earth Sculptor, available at http://earthsculptor.com  */ 
    101     void load(char[] filename) 
    102     {   // Lower priority than the other functions.  Perhaps another terrain file format is better?      
    103     } 
    104      
     65} 
     66 
     67/** 
     68 * Defines functions a class must provide in order for TerrainNode to use it to generate Terrain. */ 
     69interface TerrainGenerator 
     70{ 
     71    /// Data structure for a single vertex in the Terrain Geometry. 
     72    struct TerrainPoint 
     73    {   Vec3f position;             /// xyz position of the terrain point 
     74        Vec3f normal;               /// Normal vector for this point on the terrain, used for lighting 
     75        Vec2f textureCoordinate;    /// Texture coordinates for this point on the terrain 
     76        float[] textureBlend;       /// Normalized vector of arbitrary length specifying the amount of each texture to 
     77                                    /// use at this point.  TerrainNode.setTextures() specifies the textures themselves. 
     78    } 
     79     
     80    /** 
     81     * Get the values needed for a single vertex in the Terrain Geometry. */ 
     82    TerrainPoint getPoint(Vec2f coordinate);     
     83     
     84    /** 
     85     * Get a lightmap Texture to use across the range of coordinates. 
     86     * If no lightmap is desired, this function can return a Texture without a GPUTexture. 
     87     * The same GPU Texture can be reused across multiple calls with different values,  
     88     * if the Textures' texture matrix adjusted as needed. 
     89     * Params: 
     90     *     min = Minumum xy coordinate of the rectangle needing a lightmap. 
     91     *     max = Maximum xy coordinate of the rectangle needing a lightmap. 
     92     * Returns: An RGB texture to use as a baked light-map.  It's color values will be modulated with the terrain. */ 
     93    Texture getLightmap(Vec2f min, Vec2f max);   
     94} 
     95 
     96/** 
     97 * A sample TerrainGenerator that uses a heightmap image to specify elevation and a color texture 
     98 * to specify which textures to use at a given point. */ 
     99class HeightmapGenerator : TerrainGenerator 
     100{ 
     101    Image2!(ubyte, 1) heightMap; 
     102    Image2!(ubyte, 4)[] textures; 
     103     
     104    /** 
     105     *  
     106     * Params: 
     107     *     heightMap =  
     108     *     textures = The red component of the first textureBlend specifies how much of the first texture to use at this  
     109     *         point, The green for the second texture, blue for the third, and alpha for the fourth. 
     110     *         If more than four textures are used, the red component of the second textureBlend is used for the fifth, 
     111     *         and so on. */ 
     112    this(Image2!(ubyte, 1) heightMap, Image2!(ubyte, 4)[] textureBlend) 
     113    {   this.heightMap = heightMap; 
     114        this.textures = textures; 
     115    } 
     116     
     117    /** 
     118     * Load heightmap and textureBlends from Earth Sculptor, available at http://earthsculptor.com   */ 
     119    this(char[] filename) 
     120    { 
     121    } 
     122         
     123    TerrainPoint getPoint(Vec2f coordinate) 
     124    {   TerrainPoint result; 
     125     
     126        result.position.x = coordinate.x; 
     127        result.position.y = coordinate.y;  /// TODO: [below] It would be better to interpolate values. 
     128        result.position.z = 0; // heightMap[coordinate.x*heightMap.width, coordinate.y*heightMap.height]; 
     129         
     130        // TODO texture coordinates, normals, and textureBlend 
     131         
     132        return result; 
     133    } 
     134 
     135    Texture getLightmap(Vec2f min, Vec2f max) 
     136    {   Texture texture; 
     137        return texture; // return no lightmap for now. 
     138    } 
    105139} 
    106140