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/*
This file is part of the MinGfx Project.
Copyright (c) 2017,2018 Regents of the University of Minnesota.
All Rights Reserved.
Original Author(s) of this File:
Dan Keefe, 2018, University of Minnesota
Author(s) of Significant Updates/Modifications to the File:
...
*/
#ifndef SRC_TEXTURE2D_H_
#define SRC_TEXTURE2D_H_
#include "opengl_headers.h"
#include "color.h"
#include <string>
namespace mingfx {
/** A wrapper around a 2D texture that supports loading images from files or
setting texture color data directly. Example:
~~~
Texture2D tex1;
Texture2D tex2(GL_CLAMP_TO_EDGE);
void MyGraphicsApp::InitOpenGL() {
std::vector<std::string> search_path;
search_path.push_back(".");
search_path.push_back("./data");
search_path.push_back("./shaders");
tex1.InitFromFile(Platform::FindFile("earth-2k.png", search_path));
tex2.InitFromFile(Platform::FindFile("toon-ramp.png", search_path));
}
~~~
*/
class Texture2D {
public:
/// Creates an empty texture. Optional parameters can be provided to set
/// the texture wrap mode and filter mode.
Texture2D(GLenum wrapMode=GL_REPEAT, GLenum filterMode=GL_LINEAR);
virtual ~Texture2D();
/// Call this from within the InitOpenGL() function since it will initialize
/// not just the Texture2D's internal data but also an OpenGL texture to be
/// stored on the graphics card. Internally, this uses the stbi library to
/// load images. It supports png, jpg, bmp, and other file formats.
bool InitFromFile(const std::string &filename);
/// Call this from within the InitOpenGL() function since it will initialize
/// not just the Texture2D's internal data but also an OpenGL texture to be
/// stored on the graphics card.
/// With this version of Init, you may pass in your own pointer to color data.
/// The data argument must point to an array of 4-channel color data stored as
/// unsigned chars in RGBA format. You are responsible for managing the memory
/// for this array. If you will never call Pixel(), then it is safe to free
/// data as soon as this function returns. Otherwise, you need to make sure
/// data does not change in memory until you destroy the Texture2D object.
bool InitFromBytes(int width, int height, const unsigned char * data);
/// Call this from within the InitOpenGL() function since it will initialize
/// not just the Texture2D's internal data but also an OpenGL texture to be
/// stored on the graphics card.
/// With this version of Init, you may pass in your own pointer to color data.
/// The data argument must point to an array of 4-channel color data stored as
/// floats in RGBA format. You are responsible for managing the memory
/// for this array. If you will never call Pixel(), then it is safe to free
/// data as soon as this function returns. Otherwise, you need to make sure
/// data does not change in memory until you destroy the Texture2D object.
bool InitFromFloats(int width, int height, const float * data);
/// This function may be called to re-read the texture data from an array
/// formated the same as in InitFromBytes. The width and height of the
/// texture must remain the same.
bool UpdateFromBytes(const unsigned char * data);
/// This function may be called to re-read the texture data from an array
/// formated the same as in InitFromFloats. The width and height of the
/// texture must remain the same.
bool UpdateFromFloats(const float * data);
/// Returns true if the texture data has been successfully transferred to OpenGL.
bool initialized() const;
/// Returns the width in pixels of the texture.
int width() const;
/// Returns the height in pixels of the texture.
int height() const;
/// Returns the unsigned int used as the texture handle by OpenGL
GLuint opengl_id() const;
/// Returns an enumerated constant for the OpenGL wrap mode used by the texture.
GLenum wrap_mode() const;
/// Returns an enumerated constant for the OpenGL filter mode used by the texture.
GLenum filter_mode() const;
/// Uses the OpenGL texture wrap mode arguments
void set_wrap_mode(GLenum wrapMode);
/// Uses the OpenGL texture filter mode arguments
void set_filter_mode(GLenum filterMode);
/// Returns the color at the specified pixel. The top left corner of the
/// image is (0,0) and the bottom right is (width()-1, height()-1).
Color Pixel(int x, int y) const;
private:
bool InitOpenGL();
GLenum dataType_; // GL_UNSIGNED_BYTE or GL_FLOAT
const unsigned char * data_ubyte_;
const float * data_float_;
int width_;
int height_;
bool handleMemInternally_;
GLuint texID_;
GLenum wrapMode_;
GLenum filterMode_;
};
} // end namespace
#endif
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