C++ OpenGL纹理,没有错误,只有灰色
尝试根据纹理颜色为地形点上色(出于测试目的,当前硬编码为vec2(0.5,0.5)-应为浅蓝色),但所有点均为灰色。glGetError在整个过程中返回0。我认为渲染过程可能出错,或者着色器有问题(?) 顶点着色器:C++ OpenGL纹理,没有错误,只有灰色,c++,opengl,glsl,shader,terrain,C++,Opengl,Glsl,Shader,Terrain,尝试根据纹理颜色为地形点上色(出于测试目的,当前硬编码为vec2(0.5,0.5)-应为浅蓝色),但所有点均为灰色。glGetError在整个过程中返回0。我认为渲染过程可能出错,或者着色器有问题(?) 顶点着色器: void main(){ gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; } 片段着色器: uniform sampler2D myTextureSampler; void main(){ gl_
void main(){
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
}
片段着色器:
uniform sampler2D myTextureSampler;
void main(){
gl_FragColor = texture2D(myTextureSampler, vec2(0.5, 0.5));
}
地形等级:
class Terrain
{
public:
Terrain(GLuint pProgram, char* pHeightmap, char* pTexture){
if(!LoadTerrain(pHeightmap))
{
OutputDebugString("Loading terrain failed.\n");
}
if(!LoadTexture(pTexture))
{
OutputDebugString("Loading terrain texture failed.\n");
}
mProgram = pProgram;
mTextureLocation = glGetUniformLocation(pProgram, "myTextureSampler");
};
~Terrain(){};
void Draw()
{
glEnableClientState(GL_VERTEX_ARRAY); // Uncommenting this causes me to see nothing at all
glBindBuffer(GL_ARRAY_BUFFER, mVBO);
glVertexPointer(3, GL_FLOAT, 0, 0);
glEnable( GL_TEXTURE_2D );
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, mBMP);
glProgramUniform1i(mProgram, mTextureLocation, 0);
GLenum a = glGetError();
glPointSize(5.0f);
glDrawArrays(GL_POINTS, 0, mNumberPoints);
a = glGetError();
glBindBuffer(GL_ARRAY_BUFFER, 0);
glDisable( GL_TEXTURE_2D );
glDisableClientState(GL_VERTEX_ARRAY);
}
private:
GLuint mVBO, mBMP, mUV, mTextureLocation, mProgram;
int mWidth;
int mHeight;
int mNumberPoints;
bool LoadTerrain(char* pFile)
{
/* Definitely no problem here - Vertex data is fine and rendering nice and dandy */
}
// TEXTURES MUST BE POWER OF TWO!!
bool LoadTexture(char *pFile)
{
unsigned char header[54]; // Each BMP file begins by a 54-bytes header
unsigned int dataPos; // Position in the file where the actual data begins
unsigned int width, height;
unsigned int imageSize;
unsigned char * data;
FILE * file = fopen(pFile, "rb");
if(!file)
return false;
if(fread(header, 1, 54, file) != 54)
{
fclose(file);
return false;
}
if ( header[0]!='B' || header[1]!='M' )
{
fclose(file);
return false;
}
// Read ints from the byte array
dataPos = *(int*)&(header[0x0A]);
imageSize = *(int*)&(header[0x22]);
width = *(int*)&(header[0x12]);
height = *(int*)&(header[0x16]);
// Some BMP files are misformatted, guess missing information
if (imageSize==0) imageSize=width*height*3; // 3 : one byte for each Red, Green and Blue component
if (dataPos==0) dataPos=54; // The BMP header is done that way
// Create a buffer
data = new unsigned char [imageSize];
// Read the actual data from the file into the buffer
fread(data,1,imageSize,file);
//Everything is in memory now, the file can be closed
fclose(file);
// Create one OpenGL texture
glGenTextures(1, &mBMP);
// "Bind" the newly created texture : all future texture functions will modify this texture
glBindTexture(GL_TEXTURE_2D, mBMP);
// Give the image to OpenGL
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_BGR, GL_UNSIGNED_BYTE, data);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
delete [] data;
data = 0;
return true;
}
};
回答自己的问题,以防任何人有类似问题:
我已经用多幅图像对此进行了测试,但结果表明,我选择的图形应用程序中存在一个缺陷;它一直在导出8位位图,尽管我明确告诉它要导出24位位图。因此,基本上,回到MS Paint解决了我的问题。为MS Paint干杯。我会尝试的事情:调试bmp加载测试数据。您甚至不使用
dataPos
变量,所以请去掉它。我不确定那glTexEnvf
是做什么的,所以试着暂时注释一下。您如何知道没有发生错误?调用glGetError()
两次,但不打印任何内容。每次打电话都打印出来。