0
我使用opengl渲染場景，使用一些示例代碼和FreeImage API加載紋理。Open GL紋理，紋理座標對於呈現的內容不正確
這是我所看到的
鏈接[圖像刪除]
我可以確認，所有紋理座標0.0F和1.0F之間提供glTexCoord2f與頂點座標一起要求。
每個渲染的三角形似乎都粘貼了整個紋理（並重復）而不是由座標指定的紋理區域。
該紋理是1024x1024。
這是載入紋理
bool loadImageToTexture(const char* image_path, unsigned int &handle)
{
if(!image_path)
return false;
FREE_IMAGE_FORMAT fif = FIF_UNKNOWN;
FIBITMAP* dib(0);
BYTE* bits(0);
unsigned int width(0), height(0);
//open the file
fif = FreeImage_GetFileType(image_path, 0);
if(fif == FIF_UNKNOWN)
fif = FreeImage_GetFIFFromFilename(image_path);
if(fif == FIF_UNKNOWN)
return false;
if(FreeImage_FIFSupportsReading(fif))
dib = FreeImage_Load(fif, image_path);
if(!dib)
return false;
//is the file of the correct type
FREE_IMAGE_COLOR_TYPE type = FreeImage_GetColorType(dib);
if(FIC_RGBALPHA != type)
{
//convert to type
FIBITMAP* ndib = FreeImage_ConvertTo32Bits(dib);
dib = ndib;
}
//get data for glTexImage2D
bits = FreeImage_GetBits(dib);
width = FreeImage_GetWidth(dib);
height = FreeImage_GetHeight(dib);
if((bits == 0) || (width == 0) || (height == 0))
return false;
//create the texture in open gl
glGenTextures(1, &handle);
glBindTexture(GL_TEXTURE_2D, handle);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glPixelStorei(GL_TEXTURE_2D, 4);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height,
0, GL_RGBA, GL_UNSIGNED_BYTE, bits);
//unload the image now loaded
FreeImage_Unload(dib);
return true;
}
渲染
inline void glTexture(float textureSize, float t, float u)
{
glTexCoord2f(u/textureSize, (textureSize - t)/textureSize);
}
void processTriangle(const btVector3* triangle, const textureCoord* tc, const btVector3& normal,
const int partId, const int triangleIndex, const bool wireframe)
{
if(wireframe)
{
glBegin(GL_LINES);
glColor3f(1, 0, 0);
glVertex3d(triangle[0].getX(), triangle[0].getY(), triangle[0].getZ());
glVertex3d(triangle[1].getX(), triangle[1].getY(), triangle[1].getZ());
glColor3f(0, 1, 0);
glVertex3d(triangle[2].getX(), triangle[2].getY(), triangle[2].getZ());
glVertex3d(triangle[1].getX(), triangle[1].getY(), triangle[1].getZ());
glColor3f(0, 0, 1);
glVertex3d(triangle[2].getX(), triangle[2].getY(), triangle[2].getZ());
glVertex3d(triangle[0].getX(), triangle[0].getY(), triangle[0].getZ());
glEnd();
}
else
{
glBegin(GL_TRIANGLES);
glColor3f(1, 1, 1);
//Normals are per triangle
glNormal3f(normal.getX(), normal.getY(), normal.getZ());
glTexture(1024.0f, tc[0].t, tc[0].u);
glVertex3d(triangle[0].getX(), triangle[0].getY(), triangle[0].getZ());
glTexture(1024.0f, tc[1].t, tc[1].u);
glVertex3d(triangle[1].getX(), triangle[1].getY(), triangle[1].getZ());
glTexture(1024.0f, tc[2].t, tc[2].u);
glVertex3d(triangle[2].getX(), triangle[2].getY(), triangle[2].getZ());
glEnd();
}
}
void processAllTriangles(const btVector3& worldBoundsMin, const btVector3& worldBoundsMax)
{
btVector3 triangle[3];
textureCoord tc[3];
//go through the index list build triangles and draw them
unsigned int k = 0;
for(unsigned int i = 0; i<dVertices.size(); i+=3, k++)
{
//first vertex
triangle[0] = dVertices[i];
tc[0] = dTexCoords[i];
//second vertex
triangle[1] = dVertices[i+1];
tc[1] = dTexCoords[i+1];
//third vertex
triangle[2] = dVertices[i+2];
tc[2] = dTexCoords[i+2];
processTriangle(triangle, tc, dNormals[k], 0, 0, false);
}
}
//draw the world given the players position
void render(btScalar* m, const btCollisionShape* shape, const btVector3& color, int debugMode,
const btVector3& worldBoundsMin, const btVector3& worldBoundsMax)
{
//render the world using the generated OpenGL lists
//enable and specify pointers to vertex arrays
glPushMatrix();
glMultMatrixf(m);
glMatrixMode(GL_TEXTURE);
glLoadIdentity();
glMatrixMode(GL_MODELVIEW);
glEnable(GL_TEXTURE_2D);
glShadeModel(GL_SMOOTH);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glBindTexture(GL_TEXTURE_2D, m_texturehandle);
processAllTriangles(worldBoundsMin, worldBoundsMax);
glPopMatrix();
}