2d tile rendering using tmx-parser and SDL

Question

I'm working on getting an map created in Tiled (http://mapeditor.org) to render after parsing the map with tmx-parser (http://code.google.com/p/tmx-parser/). I've got the tiles to render in the correct positions, but i can't seem to get it to render the correct tiles from the tileset. I'm using the isometric_grass_and_water example from tiled to test it.

Here is my rendering code.

void Map::RenderMapIsometric(SDL_Surface *SurfaceDest)
    {
        for (int i = 0; i < map->GetNumLayers(); ++i) 
        {
            // Get a layer.
        this->layer = map->GetLayer(i);

        for (int x = 0; x < layer->GetWidth(); ++x) 
        {
            for (int y = 0; y < layer->GetHeight(); ++y) 
            {
                int CurTile = layer->GetTileGid(x, y);

                if(CurTile == 0)
                {
                    continue;
                }

                int tileset_col = (CurTile % (TilesetWidth / this->tileset->GetTileWidth()));
                int tileset_row = (CurTile / (TilesetWidth / this->tileset->GetTileWidth()));

                std::cout << CurTile << std::endl;

                SDL_Rect rect_CurTile;
                rect_CurTile.x = (this->tileset->GetMargin() + (this->tileset->GetTileWidth() + this->tileset->GetSpacing()) * tileset_col);
                rect_CurTile.y = (this->tileset->GetMargin() + (this->tileset->GetTileHeight() + this->tileset->GetSpacing()) * tileset_row);
                rect_CurTile.w = this->tileset->GetTileWidth();
                rect_CurTile.h = this->tileset->GetTileHeight();

                int DrawX = (x * this->tileset->GetTileWidth() / 2) + (y * this->tileset->GetTileWidth() / 2);
                int DrawY = (y * this->tileset->GetTileHeight() / 2) - (x * this->tileset->GetTileHeight() / 2);

                apply_surfaceClip(DrawX, DrawY, surf_Tileset, SurfaceDest, &rect_CurTile); 
            }
        }
    }
}

Can anyone point out what i'm doing wrong?

Answer 1

I found the answer after some brute force here is the changed working code if anyone else needs it: PS: Num_Of_Cols is the same thing as (TilesetWidth / TileWidth)

void Map::RenderMapIsometric(SDL_Surface *SurfaceDest)
{

for (int i = 0; i < map->GetNumLayers(); ++i) 
    {
        // Get a layer.
        this->layer = map->GetLayer(i);

    for (int x = 0; x < layer->GetWidth(); ++x) 
    {
        for (int y = 0; y < layer->GetHeight(); ++y) 
        {
            int CurTile = layer->GetTileGid(x, y);

            if(CurTile == 0)
            {
                continue;
            }

            //CurTile = tileset->GetFirstGid() + CurTile;
            CurTile--;

            int tileset_col = (CurTile % Num_Of_Cols);
            int tileset_row = (CurTile / Num_Of_Cols);

            SDL_Rect rect_CurTile;
            rect_CurTile.x = (this->tileset->GetMargin() + (this->tileset->GetTileWidth() + this->tileset->GetSpacing()) * tileset_col);
            rect_CurTile.y = (this->tileset->GetMargin() + (this->tileset->GetTileHeight() + this->tileset->GetSpacing()) * tileset_row);
            rect_CurTile.w = this->tileset->GetTileWidth();
            rect_CurTile.h = this->tileset->GetTileHeight();

            int DrawX = (x * this->tileset->GetTileWidth() / 2) + (y * this->tileset->GetTileWidth() / 2);
            int DrawY = (y * this->tileset->GetTileHeight() / 2) - (x * this->tileset->GetTileHeight() / 2);

            apply_surfaceClip(DrawX, DrawY, surf_Tileset, SurfaceDest, &rect_CurTile); 
        }
    }
}
}