我在下面发布了渲染器代码，因为这里的代码似乎不是问题。
我遇到了一些我的代码问题，当我尝试将多个纹理上传到openGL时，一次一个，它有点奇怪地失败，渲染器最终只使用一个纹理。我已经做了一些调试来跟踪这个函数的错误，但是我在弄清楚函数的哪个部分有问题时遇到了问题。有没有特别明显的搞砸我正在制作，我根本没有看到，或者我的代码中是否有更微妙的缺陷？
这是我用来存储纹理信息的结构，通常只是跟踪我的所有指针
typedef struct {
float Width;
float Height;
} texInfo;
typedef struct {
dshlib::utfstr ResourceName;
texInfo * TextureInfo;
GLuint TextureNum;
SDL_Surface * Image;
} texCacheItem;
这是目前的WIP图形加载器。基本上，它使用预先编写的库从.zip存档中加载一个名为.png的文件（顺便提一下，它正在使用此程序进行测试）。然后它加载了libpng，然后作为纹理加载，并加入缓存以加速加载并避免多次加载单个纹理。我省略了#include语句，因为它们只是残酷的。
texCacheItem * loadGraphics(dshlib::utfstr FileName) {
for(int i = 0; i < NumTexCached; i++) { //First see if this texture has already been loaded
if(TextureCache[i]->ResourceName == FileName)
return TextureCache[i];
}
dshlib::utfstr FullFileName = "Data/Graphics/"; //If not, create the full file path in the archive
FullFileName += FileName;
dshlib::FilePtr file = resourceCtr.OpenFile(FullFileName); //And open the file
if (!file->IsOk()) { //If the file failed to load...
EngineState = ENGINESTATE_ERR;
return NULL;
}
SDL_Surface * T = loadPNG(file);
texCacheItem * Texture = new texCacheItem;
Texture->TextureInfo = new texInfo;
glGenTextures(1, &Texture->TextureNum); //Allocate one more texture and save the name to the texCacheItem
glBindTexture(GL_TEXTURE_2D, Texture->TextureNum); //Then create it
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, T->w, T->h, 0, GL_RGBA, GL_UNSIGNED_BYTE, T->pixels);
Texture->TextureInfo->Width = (float)T->w; //Write the useful data
Texture->TextureInfo->Height = (float)T->h;
Texture->ResourceName = FileName; //And the caching info needed
Texture->Image = T; //And save the image for if it's needed later and for deleting
if (!TexCacheSize) { //If this is the first load this is 0, so allocate the first 8 Cache slots.
TexCacheSize = 8;
TextureCache = new texCacheItem*[8];
}
if(NumTexCached == TexCacheSize) { //If we're out of cache space
if (TexCacheSize == 32768) { //If too many cache items, error out
EngineState = ENGINESTATE_ERR;
return NULL;
}
TexCacheSize <<= 1; //Double cache size
texCacheItem ** NewSet = new texCacheItem*[TexCacheSize];
memcpy(NewSet, TextureCache, NumTexCached * sizeof(texCacheItem*)); //And copy over the old cache
delete TextureCache; //Delete the old cache
TextureCache = NewSet; //And assign the pointer to the new one
}
TextureCache[NumTexCached++] = Texture; //Store the texCacheItem to the Cache
file->Close(); //Close the file
file = NULL; //And NULL the smart pointer. [NTS: Confirm with Disch this is what won't cause a memory leak]
return Texture; //And return the loaded texture in texCacheItem form.
}
SDL_Surface *loadPNG(dshlib::FilePtr File)
{
Uint8 *PNGFile = new Uint8[(long)File->GetSize()];
File->GetAr<Uint8>(PNGFile, (long)File->GetSize());
return IMG_LoadPNG_RW(SDL_RWFromMem(PNGFile, (long)File->GetSize()));
}
这是渲染器代码文件。这一刻非常混乱，为此道歉。 level-＆gt; activeMap基本上告诉渲染器tilemap的“图层”（0是前面，3是后面）来绘制上面的精灵。
#include "../MegaJul.h"
void render(void) {
//Render the current tilemap to the screen
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(0.0f, 0.0f, -4.0f);
if (level) {
glBegin(GL_QUADS);
float dT = 32.0f / level->dTex;
float sX, fX, fXa, sY, tX, tY, sYa, sYb, sXa, tXa, tYa;
unsigned long m = level->mapDimensions[0] * level->mapDimensions[1];
float ai; long long t; Sint16 * p;
glBindTexture(GL_TEXTURE_2D, level->tilemap->TextureNum);
for (int i = 3; i >= 0; i--) {
if (level->layers[i]->mapPosition[0] > 0)
level->layers[i]->mapPosition[0] = 0;
if (level->layers[i]->mapPosition[0] < 0 - (signed long)((level->mapDimensions[0] - 21) * 32))
level->layers[i]->mapPosition[0] = 0 - (signed long)((level->mapDimensions[0] - 21) * 32);
if (level->layers[i]->mapPosition[1] < 0)
level->layers[i]->mapPosition[1] = 0;
if (level->layers[i]->mapPosition[1] > (signed long)((level->mapDimensions[1] - 16) * 32))
level->layers[i]->mapPosition[1] = (signed long)((level->mapDimensions[1] - 16) * 32);
if (i == level->activeMap) {
for (int j = 0; j < NumSprites; j++) {
glBindTexture(GL_TEXTURE_2D, Sprites[j]->Graphics->TextureNum);
Sprites[j]->render(level->layers[i]->mapPosition[0], level->layers[i]->mapPosition[1]);
}
for (int j = 0; j < NumBullets; j++) {
glBindTexture(GL_TEXTURE_2D, Bullets[j]->Texture->TextureNum);
Bullets[j]->render(level->layers[i]->mapPosition[0], level->layers[i]->mapPosition[1]);
}
}
glBindTexture(GL_TEXTURE_2D, level->tilemap->TextureNum);
t = 0 - ((level->layers[i]->mapPosition[0] - (level->layers[i]->mapPosition[0] % 32)) /32) + (((level->layers[i]->mapPosition[1] - (level->layers[i]->mapPosition[1] % 32)) /32) * level->mapDimensions[0]);
ai = (float)(3 - i); //Invert Z-Index
sX = (float)((level->layers[i]->mapPosition[0] % 32));
sY = (float)((level->layers[i]->mapPosition[1] % 32));
if (sX > 0)
sX -= 32;
if (sY < 0)
sY += 32;
fX = sX /= 32.0f;
sY /= 32.0f;
fXa = sXa = sX + 1.0f;
sYa = sY + 14.0f;
sYb = sY + 15.0f;
for (int y = 0; y < 16; y++) {
for (int x = 0; x < 21; x++) {
p = level->tiles[level->layers[i]->map[t]]->position;
tX = p[0] / level->dTex;
tY = p[1] / level->dTex;
tXa = tX + dT;
tYa = tY + dT;
glTexCoord2f(tX, tYa); glVertex3f(fX, sYa, ai); // Bottom Left Of The Texture and Quad
glTexCoord2f(tXa,tYa); glVertex3f(fXa, sYa, ai); // Bottom Right Of The Texture and Quad
glTexCoord2f(tXa,tY); glVertex3f(fXa, sYb, ai); // Top Right Of The Texture and Quad
glTexCoord2f(tX, tY); glVertex3f(fX, sYb, ai); // Top Left Of The Texture and Quad
fX += 1.0f;
fXa += 1.0f;
t++;
if (t >= m) break;
}
sYb -= 1.0f; sYa -= 1.0f;
fXa = sXa; fX = sX;
t += level->mapDimensions[0] - 21; //21 is the number of tiles drawn on a line (20 visible + 1 extra for scrolling)
}
}
glEnd();
}
SDL_GL_SwapBuffers();
}
这是为精灵和级别设置tilemap数据的代码段：
等级：
void loadLevel(dshlib::utfstr FileName) {
-snip-
texCacheItem * Tex = loadGraphics(FileName);
if (!Tex) { //Load the tile graphics for the level
unloadLevel();
EngineState = ENGINESTATE_ERR;
return;
} else {
level->dTex = Tex->TextureInfo->Width;
level->tilemap = Tex;
}
-snip-
}
的Sprite：
void SpriteBase::created() {
this->Graphics = loadGraphics(DefaultGFX());
-snip-
}
Sid Farkus注意到我对渲染器犯了一个大错误，所以这里有一个更新的渲染器.pp：
#include "../MegaJul.h"
void render(void) {
//Render the current tilemap to the screen
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(0.0f, 0.0f, -4.0f);
if (level) {
float dT = 32.0f / level->dTex;
float sX, fX, fXa, sY, tX, tY, sYa, sYb, sXa, tXa, tYa;
unsigned long m = level->mapDimensions[0] * level->mapDimensions[1];
float ai; long long t; Sint16 * p;
for (int i = 3; i >= 0; i--) {
if (level->layers[i]->mapPosition[0] > 0)
level->layers[i]->mapPosition[0] = 0;
if (level->layers[i]->mapPosition[0] < 0 - (signed long)((level->mapDimensions[0] - 21) * 32))
level->layers[i]->mapPosition[0] = 0 - (signed long)((level->mapDimensions[0] - 21) * 32);
if (level->layers[i]->mapPosition[1] < 0)
level->layers[i]->mapPosition[1] = 0;
if (level->layers[i]->mapPosition[1] > (signed long)((level->mapDimensions[1] - 16) * 32))
level->layers[i]->mapPosition[1] = (signed long)((level->mapDimensions[1] - 16) * 32);
if (i == level->activeMap) {
for (int j = 0; j < NumSprites; j++) {
glBindTexture(GL_TEXTURE_2D, Sprites[j]->Graphics->TextureNum);
glBegin(GL_QUADS);
Sprites[j]->render(level->layers[i]->mapPosition[0], level->layers[i]->mapPosition[1]);
glEnd();
}
for (int j = 0; j < NumBullets; j++) {
glBindTexture(GL_TEXTURE_2D, Bullets[j]->Texture->TextureNum);
glBegin(GL_QUADS);
Bullets[j]->render(level->layers[i]->mapPosition[0], level->layers[i]->mapPosition[1]);
glEnd();
}
}
glBindTexture(GL_TEXTURE_2D, level->tilemap->TextureNum);
glBegin(GL_QUADS);
-snipped out renderer since it was bloat
glEnd();
}
SDL_GL_SwapBuffers();
}
答案 0 :(得分：3)
使用渲染代码，我可以看到你在glBegin / End块中调用BindTexture。来自opengl文档：
如果生成GL_INVALID_OPERATION glBindTexture之间执行 glBegin的执行和glEnd的相应执行。
将你的BindTexture调用移到glBegin（）/ glEnd（）块之外，你应该是金色的。你可能需要有多个块来适应你的渲染风格。
编辑：
使用更新的代码，确保一些事情;使用当前投影/模型视图矩阵在屏幕上显示您的精灵位置，并且精灵纹理ID是有效纹理。现在跳出来对我来说没有什么技术上的错误，但是你的价值可能会被关闭。
答案 1 :(得分：2)
在渲染器中，您是否正确调用了glBindTexture？听起来你的渲染器只是使用你上传的最后一个纹理，因为这是你最后一次调用glBindTexture。 glBindTexture告诉OpenGL纹理用于你的多边形。
答案 2 :(得分：0)
我假设您无法进行任何调试或记录此操作？如果可以，我希望这对于诊断来说是微不足道的。
对我来说看起来很危险的主要事情是你没有检查loadPNG的返回值。我在那里做了第一件事。
我也会考虑对已经缓存的纹理进行初始检查。如果事情在那时开始工作，你知道它是资源名称或文件名（或它们的比较）的问题。
顺便说一句，我很惊讶您正在使用类和智能指针，但使用裸指针和数组滚动您自己的std :: vector。 ;）