hwDecalBumpShader_NV20/MTexture.h

hwDecalBumpShader_NV20/MTexture.h
#ifndef MAYA_API_MTexture
#define MAYA_API_MTexture
//-
// Copyright 2015 Autodesk, Inc. All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk
// license agreement provided at the time of installation or download,
// or which otherwise accompanies this software in either electronic
// or hard copy form.
//+
// MTexture.h
// DESCRIPTION: Texture object, that can be mipmapped. Eventually, this
// class will likely end up in the Maya API.
//
// AUTHOR: Christian Laforte
//
#include <maya/MImage.h>
#include <maya/MString.h>
#include <assert.h>
#include <maya/MGL.h>
int highestPowerOf2(int num);
class TexObj
{
public:
TexObj(GLenum target = GL_TEXTURE_2D)
{
assert(glGetError() == GL_NO_ERROR);
// Get a texture identifier.
glGenTextures(1, &fTextureNum);
assert(glGetError() == GL_NO_ERROR);
fTarget = target;
// Set up default values for the texture parameters.
// They are the same as the OpenGL default.
fMinFilterParam = GL_NEAREST;
fMagFilterParam = GL_LINEAR;
fWrapSParam = GL_REPEAT;
fWrapTParam = GL_REPEAT;
}
~TexObj()
{
glDeleteTextures(1, &fTextureNum);
}
void bind()
{
assert(glGetError() == GL_NO_ERROR);
// Bind the texture.
glBindTexture(fTarget, fTextureNum);
assert(glGetError() == GL_NO_ERROR);
// Set up the texture parameters.
glTexParameteri(fTarget, GL_TEXTURE_MIN_FILTER, fMinFilterParam);
assert(glGetError() == GL_NO_ERROR);
glTexParameteri(fTarget, GL_TEXTURE_MAG_FILTER, fMagFilterParam);
assert(glGetError() == GL_NO_ERROR);
glTexParameteri(fTarget, GL_TEXTURE_WRAP_S, fWrapSParam);
assert(glGetError() == GL_NO_ERROR);
glTexParameteri(fTarget, GL_TEXTURE_WRAP_T, fWrapTParam);
assert(glGetError() == GL_NO_ERROR);
}
void parameter(GLenum pname, GLint param)
{
switch (pname)
{
case GL_TEXTURE_MIN_FILTER: fMinFilterParam = param; break;
case GL_TEXTURE_MAG_FILTER: fMagFilterParam = param; break;
case GL_TEXTURE_WRAP_S: fWrapSParam = param; break;
case GL_TEXTURE_WRAP_T: fWrapTParam = param; break;
}
}
private:
GLenum fTarget;
// Various parameters. See glTexParameterf() in MSDN for more info.
GLint fMinFilterParam;
GLint fMagFilterParam;
GLint fWrapSParam;
GLint fWrapTParam;
GLuint fTextureNum;
};
class MTexture
{
public:
enum Type
{
RGBA,
HILO,
NMAP
};
MTexture();
~MTexture()
{
if (m_levels)
{
for (unsigned int i=0; i < m_numLevels; i++)
{
if (m_levels[i])
{
delete [] m_levels[i];
m_levels[i] = NULL;
}
}
delete [] m_levels;
}
}
bool set(MImage &image, Type type, bool mipmapped = true, GLenum target = GL_TEXTURE_2D);
// This function assumes that the file texture is square, and
// that its dimensions are exponents of 2.
bool load(MString filename, Type type, bool mipmapped = true, GLenum target = GL_TEXTURE_2D);
bool specify(GLenum target);
// Returns 1 if no mipmapping, >1 otherwise.
unsigned int levels() { return m_numLevels; }
bool bind();
unsigned char* fetch(unsigned int s, unsigned int t, unsigned int level = 0)
{
// Verify that the mipmap level exists.
if (level > m_numLevels || m_levels == NULL || m_levels[level] == NULL)
return NULL;
return internalFetch(s, t, level);
}
inline bool square()
{
return m_width == m_height;
}
inline bool mipmapped()
{
return levels() > 1;
}
// Return the width of a specific mipmap level.
// If level == 0, return the width of the base level (source image).
// Width is always >= 1, to prevent non-square textures from having zero-sized levels.
inline unsigned int width(unsigned int level = 0)
{
unsigned int w = m_width >> level;
if (w > 0)
return w;
else
return 1;
}
inline unsigned int height(unsigned int level = 0)
{
unsigned int h = m_height >> level;
if (h > 0)
return h;
else
return 1;
}
protected:
inline unsigned char* internalFetch(unsigned int s, unsigned int t, unsigned int level)
{
assert((s >= 0) && (s < width(level)));
assert((t >= 0) && (t < height(level)));
return m_levels[level] + 4 * ((width(level) * t) + s);
}
private:
// Fairly permanent variables
unsigned int m_width, m_height;
Type m_type;
TexObj m_texObj;
bool m_mipmapped;
// Pyramid levels (assumes 4 bytes per pixel for now)
unsigned char **m_levels;
unsigned int m_numLevels; // Number of mipmaps + base texture
// Cached variables (Depend on previous private variables)
GLint m_internalFormat;
GLenum m_format;
GLenum m_componentFormat;
};
#endif // MAYA_API_MTexture