无缝Tilemap渲染C ++

Question

我正在尝试用C ++创建一个无缝的2D tilemap渲染器。当玩家从每个地图前进到另一个地图时，目标是几乎没有加载屏幕。

例如： 上图中的每个方块都是区域/瓦片图;红色方块是可视的相机。在这个例子中，每个区域是256x256并存储在std::vector<std::vector<int> >内 - 还可以说相机的可视区域为60x60（32x32块）

我目前的问题是如何决定：

1. 每个指定区域显示哪些图块。
2. 如何计算用于绘制所述图块的偏移量。

略有关联，如果有人有兴趣创造这项技术，我非常愿意付钱：）

我是一名贸易软件工程师，但图形不是我的强项。最终目标是使用带有着色器支持的OpenGL 3.2开发一个旧学校RPG。

谢谢大家！

Answer 1

哇，这让我回来..好的，这是我在当天实现的方式（使用directdraw 7，但实际上这背后的图形引擎是无关紧要的）。此代码仅绘制相机在任何给定点可以看到的内容（这是您应该绘制的唯一内容）。还要记住，这个代码是OLD，当我第一次开始学习如何开发时。它不会很漂亮：

// set original render location to x = 0, y = 0, width = tileWidth, height = tileHeight
// this is the top left corner of the screen
RECT renderLoc = { 0, 0, g_MapData.m_TileSize, g_MapData.m_TileSize }; 

// the first column of visible tiles is given by the x coordinate divided 
// by the tilesize and first visible row is given by the y coordinate/tileWidth
int xStartCol = g_MapData.m_xCamera / g_MapData.m_TileSize;
int yStartRow = g_MapData.m_yCamera / g_MapData.m_TileSize;

// calculate the number of tiles in the current resolution that are visible
int xVisibleTiles = (dd7.m_ScreenWidth/g_MapData.m_TileSize);
int yVisibleTiles = (dd7.m_ScreenHeight/g_MapData.m_TileSize);

// if the tilesize is not divisible by the screensize then the 
// number of visible tiles will not calculate correctly. It will 
// be a float and since this is truncated, it will contain a row or 
// column less than what it requires. This code compensates for that
// by just adding one more row to round up instead of down.
if (dd7.m_ScreenWidth%g_MapData.m_TileSize) { xVisibleTiles++; }

if (dd7.m_ScreenHeight%g_MapData.m_TileSize) { yVisibleTiles++; }

// now just add the size in tiles of the visible screen to get the end
int xEndCol = xStartCol + xVisibleTiles;
int yEndRow = yStartRow + yVisibleTiles;

// Visible tiles referring to the tiles that can be displayed across and 
//down on the screen (this depends on the resolution set)

// now check if the camera coordinates are divisible by the tile size
int x, y, l; // variables for loops and checks

x = g_MapData.m_xCamera % g_MapData.m_TileSize;
y = g_MapData.m_yCamera % g_MapData.m_TileSize;

if (!x)
{
    // remove a column to draw since it divided perfectly. We originally    
    //added one to the visible rows and columns
xEndCol--;
}
else 
{
// need to move renderLoc RECT. Since there could be half a column    
//exposed which forces us to draw that portion. we only want to draw what 
//is currently on the viewable screen to save memory.
renderLoc.left -= x;
renderLoc.right -= x;
}

// now do the same for rows
if (!y)
{
yEndRow--;
else 
{
renderLoc.top -= y;
renderLoc.bottom -= y;
}

// now check to make sure we're not exceeding map size
if (xEndCol > g_MapData.m_xMaxTiles) { xEndCol = g_MapData.m_xMaxTiles; }
if (yEndRow > g_MapData.m_yMaxTiles) { yEndRow = g_MapData.m_yMaxTiles; }

// Now Draw!
// for each layer 
for ( l = 0; l < g_MapData.m_Layers; l++) {
// draw the rows
for ( x = xStartCol; x <= xEndCol; x++) {
    // column by column
    for ( y = yStartRow; y <= yEndRow; y++) {               
    tileToRender = g_MapData.m_Tiles[x][y][l]; 
// Finish your drawing..