JUCE/modules/juce_opengl/opengl/juce_OpenGLTexture.h

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2013 - Raw Material Software Ltd.

   Permission is granted to use this software under the terms of either:
   a) the GPL v2 (or any later version)
   b) the Affero GPL v3

   Details of these licenses can be found at: www.gnu.org/licenses

   JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

   ------------------------------------------------------------------------------

   To release a closed-source product which uses JUCE, commercial licenses are
   available: visit www.juce.com for more information.

  ==============================================================================
*/

#ifndef JUCE_OPENGLTEXTURE_H_INCLUDED
#define JUCE_OPENGLTEXTURE_H_INCLUDED

//==============================================================================
/**
    Creates an openGL texture from an Image.
*/
class JUCE_API  OpenGLTexture
{
public:
    OpenGLTexture();
    ~OpenGLTexture();

    /** Creates a texture from the given image.

        Note that if the image's dimensions aren't a power-of-two, the texture may
        be created with a larger size.

        The image will be arranged so that its top-left corner is at texture
        coordinate (0, 1).
    */
    void loadImage (const Image& image);

    /** Creates a texture from a raw array of pixels.
        If width and height are not powers-of-two, the texture will be created with a
        larger size, and only the subsection (0, 0, width, height) will be initialised.
        The data is sent directly to the OpenGL driver without being flipped vertically,
        so the first pixel will be mapped onto texture coordinate (0, 0).
    */
    void loadARGB (const PixelARGB* pixels, int width, int height);

    /** Creates a texture from a raw array of pixels.
        This is like loadARGB, but will vertically flip the data so that the first
        pixel ends up at texture coordinate (0, 1), and if the width and height are
        not powers-of-two, it will compensate by using a larger texture size.
    */
    void loadARGBFlipped (const PixelARGB* pixels, int width, int height);

    /** Creates an alpha-channel texture from an array of alpha values.
        If width and height are not powers-of-two, the texture will be created with a
        larger size, and only the subsection (0, 0, width, height) will be initialised.
        The data is sent directly to the OpenGL driver without being flipped vertically,
        so the first pixel will be mapped onto texture coordinate (0, 0).
    */
    void loadAlpha (const uint8* pixels, int width, int height);

    /** Frees the texture, if there is one. */
    void release();

    /** Binds the texture to the currently selected openGL context. */
    void bind() const;

    /** Unbinds the texture to the currently selected openGL context. */
    void unbind() const;

   #if JUCE_USE_OPENGL_FIXED_FUNCTION
    /** Draws this texture into the current context, with the specified corner positions. */
    void draw2D (float x1, float y1,
                 float x2, float y2,
                 float x3, float y3,
                 float x4, float y4,
                 Colour colour) const;

    /** Draws this texture into the current context, with the specified corner positions. */
    void draw3D (float x1, float y1, float z1,
                 float x2, float y2, float z2,
                 float x3, float y3, float z3,
                 float x4, float y4, float z4,
                 Colour colour) const;
   #endif

    /** Returns the GL texture ID number. */
    GLuint getTextureID() const noexcept        { return textureID; }

    int getWidth() const noexcept               { return width; }
    int getHeight() const noexcept              { return height; }

    /** Returns true if a texture can be created with the given size.
        Some systems may require that the sizes are powers-of-two.
    */
    static bool isValidSize (int width, int height);

private:
    GLuint textureID;
    int width, height;
    OpenGLContext* ownerContext;

    void create (int w, int h, const void*, GLenum, bool topLeft);

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (OpenGLTexture)
};


#endif   // JUCE_OPENGLTEXTURE_H_INCLUDED