From: Mikko Rasa Date: Thu, 9 Aug 2012 19:32:47 +0000 (+0300) Subject: Comment updates for texture and framebuffer classes. X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=e003d7a1497dad3b13e4e88e681f8fa2afc40c83;p=libs%2Fgl.git Comment updates for texture and framebuffer classes. --- diff --git a/source/framebuffer.h b/source/framebuffer.h index e33deda9..cf64b45c 100644 --- a/source/framebuffer.h +++ b/source/framebuffer.h @@ -66,7 +66,8 @@ A framebuffer consist of a number of logical buffers, such as color and depth buffers. Renderbuffers and Textures can be attached to the logical buffers. At least one image must be attached for the framebuffer to be usable. -Requires the GL_EXT_framebuffer_object extension. +Requires the GL_EXT_framebuffer_object extension. The blit functions require +the GL_EXT_framebuffer_blit extension. */ class Framebuffer: public Bindable { @@ -112,17 +113,27 @@ public: void attach(FramebufferAttachment attch, TextureCube &tex, TextureCubeFace face, unsigned level = 0); void detach(FramebufferAttachment attch); - /** - Checks the completeness status of the framebuffer. Returns - FRAMEBUFFER_COMPLETE if the framebuffer is complate and can be rendered to, - or one of the error status codes otherwise. - */ + /** Checks the completeness of the framebuffer. Returns + FRAMEBUFFER_COMPLETE if the framebuffer is complete and can be rendered to, + or one of the error status codes otherwise. */ FramebufferStatus check_status() const; void clear(BufferBits); - void blit_from(const Framebuffer &, int, int, int, int, int, int, int, int, BufferBits, bool); - void blit_from(const Framebuffer &, int, int, unsigned, unsigned, int, int, BufferBits); - void blit_from(const Framebuffer &, BufferBits, bool); + + /** Blits a region from another framebuffer into this one. If the source + and destination regions have different dimensions, the contents will be + stretched. If filter is true, linear interpolation will be used, otherwise + no interpolation is done. */ + void blit_from(const Framebuffer &other, int sx0, int sy0, int sx1, int sy1, + int dx0, int dy0, int dx1, int dy1, BufferBits bits, bool filter); + + /** Blits a region from another framebuffer into this one, retaining its + dimensions. */ + void blit_from(const Framebuffer & other, int sx, int sy, + unsigned wd, unsigned ht, int dx, int dy, BufferBits bits); + + /** Blits the entire contents of another framebuffer into this one. */ + void blit_from(const Framebuffer &other, BufferBits bits, bool filter); void bind() const; diff --git a/source/renderbuffer.cpp b/source/renderbuffer.cpp index 6d9592b1..240cf84c 100644 --- a/source/renderbuffer.cpp +++ b/source/renderbuffer.cpp @@ -18,21 +18,21 @@ Renderbuffer::~Renderbuffer() glDeleteRenderbuffersEXT(1, &id); } -void Renderbuffer::storage(PixelFormat fmt, unsigned w, unsigned h) +void Renderbuffer::storage(PixelFormat fmt, unsigned wd, unsigned ht) { Bind _bind(this, true); - width = w; - height = h; + width = wd; + height = ht; glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, fmt, width, height); } -void Renderbuffer::storage_multisample(unsigned samples, PixelFormat fmt, unsigned w, unsigned h) +void Renderbuffer::storage_multisample(unsigned samples, PixelFormat fmt, unsigned wd, unsigned ht) { static RequireExtension _ext("GL_EXT_framebuffer_multisample"); Bind _bind(this, true); - width = w; - height = h; + width = wd; + height = ht; glRenderbufferStorageMultisampleEXT(GL_RENDERBUFFER_EXT, samples, fmt, width, height); } diff --git a/source/renderbuffer.h b/source/renderbuffer.h index 977f2453..efcf5658 100644 --- a/source/renderbuffer.h +++ b/source/renderbuffer.h @@ -10,9 +10,11 @@ namespace GL { /** A Renderbuffer contains a single renderable image. It can be attached to a Framebuffer to provide a logical buffer that is required to render the scene -correctly but that is not needed as a texture later. +correctly but that is not needed as a texture later. Renderbuffers also +provide a capability for multisampling, which is not available in textures. -Requires the GL_EXT_framebuffer_object extension. +Requires the GL_EXT_framebuffer_object extension. Multisample renderbuffers +additionally require the GL_EXT_framebuffer_multisample extension. */ class Renderbuffer: public Bindable { @@ -29,8 +31,14 @@ public: unsigned get_width() const { return width; } unsigned get_height() const { return height; } - void storage(PixelFormat fmt, unsigned width, unsigned height); - void storage_multisample(unsigned, PixelFormat fmt, unsigned, unsigned); + /** Allocates storage for the renderbuffer. */ + void storage(PixelFormat fmt, unsigned wd, unsigned ht); + + /** Allocates multisample storage for the renderbuffer. All attachments in + a framebuffer must have the same number of samples. To transfer the + contents to a texture for furter processing, use the framebuffer blit + functions.*/ + void storage_multisample(unsigned samples, PixelFormat fmt, unsigned wd, unsigned ht); void bind() const; diff --git a/source/texture.h b/source/texture.h index 58051725..30ad484c 100644 --- a/source/texture.h +++ b/source/texture.h @@ -10,19 +10,35 @@ namespace GL { enum TextureFilter { - NEAREST = GL_NEAREST, - LINEAR = GL_LINEAR, + /// No filtering + NEAREST = GL_NEAREST, + + /// Bilinear filtering + LINEAR = GL_LINEAR, + + /// Mipmapping without filtering NEAREST_MIPMAP_NEAREST = GL_NEAREST_MIPMAP_NEAREST, - NEAREST_MIPMAP_LINEAR = GL_NEAREST_MIPMAP_LINEAR, - LINEAR_MIPMAP_NEAREST = GL_LINEAR_MIPMAP_NEAREST, - LINEAR_MIPMAP_LINEAR = GL_LINEAR_MIPMAP_LINEAR + + /// Linear filtering between two mipmap levels + NEAREST_MIPMAP_LINEAR = GL_NEAREST_MIPMAP_LINEAR, + + /// Bilinear filtering on the closest mipmap level + LINEAR_MIPMAP_NEAREST = GL_LINEAR_MIPMAP_NEAREST, + + /// Trilinear filtering between two mipmap levels + LINEAR_MIPMAP_LINEAR = GL_LINEAR_MIPMAP_LINEAR }; enum TextureWrap { - REPEAT = GL_REPEAT, - CLAMP_TO_EDGE = GL_CLAMP_TO_EDGE, + /// Tile the texture infinitely + REPEAT = GL_REPEAT, + + /// Extend the texels at the edge of the texture to infinity + CLAMP_TO_EDGE = GL_CLAMP_TO_EDGE, + + /// Tile the texture, with every other repetition mirrored MIRRORED_REPEAT = GL_MIRRORED_REPEAT }; @@ -31,6 +47,21 @@ enum TextureWrap Base class for textures. This class only defines operations common for all texture types and is not instantiable. For specifying images for textures, see one of the dimensioned texture classes. + +A texture is generally rendered at a size that's either smaller or larger than +its native size, so that the texture coordinates do not exactly correspond to +the texels of the texture. The kind of filtering used, if any, is determined +by the minification and magnification filter parameters. The default is LINEAR +for magnification and NEAREST_MIPMAP_LINEAR for minification. + +When a mipmapped filter is in use, the texture consists of a stack of mipmap +images. Level 0 is the base image. Each level above 0 has half the size of +the previous level, rounded down and clamped to 1. The level with size 1 in +all dimensions is the last mipmap level. All levels must be allocated for the +texture to be usable. + +If texture coordinates fall outside of the principal range of the texture, +wrapping is applied. The default for all directions is REPEAT. */ class Texture { @@ -83,13 +114,27 @@ protected: public: void set_min_filter(TextureFilter); void set_mag_filter(TextureFilter); + + /** Sets the wrapping mode for all coordinates. */ void set_wrap(TextureWrap); + void set_wrap_s(TextureWrap); void set_wrap_t(TextureWrap); void set_wrap_r(TextureWrap); + + /** Sets automatic mipmap generation. If enabled, mipmaps are generated + when a texture image is uploaded. */ void set_generate_mipmap(bool); + + /** Sets depth texture comparison. Has no effect on other formats. When + comparison is enabled, the third component of the texture coordinate is + compared against the texel value, and the result is returned as the texture + sample. */ void set_compare_enabled(bool); + + /** Sets the function to use for depth comparison. */ void set_compare_func(Predicate); + GLenum get_target() const { return target; } unsigned get_id() const { return id; } diff --git a/source/texture2d.h b/source/texture2d.h index 5f4a7f92..ff4d35b6 100644 --- a/source/texture2d.h +++ b/source/texture2d.h @@ -11,7 +11,9 @@ namespace Msp { namespace GL { /** -Two-dimensional texture class. This is the most common type of texture. +Two-dimensional texture. Consists of an array of texels in the shape of a +rectangle. Texture coordinate have a principal range of [0, 1]. This is the +most common type of texture. */ class Texture2D: public Texture { @@ -36,31 +38,28 @@ private: public: Texture2D(); - /** - Defines the texture storage. This function may only be successfully called - once. - */ + /** Defines storage structure for the texture. Must be called before an + image can be uploaded. Once storage is defined, it can't be changed. */ void storage(PixelFormat fmt, unsigned wd, unsigned ht); - /** Allocates texture storage. If storage has already been allocated, this - function does nothing. */ + /** Allocates storage for the texture. The contents are initially + undefined. If storage has already been allocated, does nothing. */ void allocate(unsigned level); - /** Uploads an image to the texture. storage() must have been called prior to - this, and the image must have dimensions conforming to the specified - storage. For level>0, mipmapping rules apply to the image dimensions. */ + /** Uploads an image to the texture. Storage must be defined beforehand. + The image data must have dimensions and format compatible with the defined + storage. */ void image(unsigned level, PixelFormat fmt, DataType type, const void *data); - /** - Uploads a sub-image into the texture. Unlike full image upload, there are - no constraints on the size of the sub-image. - */ - void sub_image(unsigned level, int x, int y, unsigned wd, unsigned ht, PixelFormat fmt, DataType type, const void *data); + /** Updates a rectangular region of the texture. Storage must be defined + and allocated beforehand. The update region must be fully inside the + texture. */ + void sub_image(unsigned level, int x, int y, unsigned wd, unsigned ht, + PixelFormat fmt, DataType type, const void *data); - /** - Loads an image from a file and uploads it to the texture. If storage() has - not been called, the storage format will be set to match the loaded image. - */ + /** Loads an image from a file and uploads it to the texture. If storage + has not been defined, it will be set to match the loaded image. Otherwise + the image must be compatible with the defined storage. */ void load_image(const std::string &fn); unsigned get_width() const { return width; } diff --git a/source/texture3d.cpp b/source/texture3d.cpp index 30363acc..33b25ccc 100644 --- a/source/texture3d.cpp +++ b/source/texture3d.cpp @@ -21,17 +21,17 @@ Texture3D::Texture3D(): static RequireVersion _ver(1, 2); } -void Texture3D::storage(PixelFormat f, unsigned w, unsigned h, unsigned d) +void Texture3D::storage(PixelFormat fmt, unsigned wd, unsigned ht, unsigned dp) { if(width>0) throw invalid_operation("Texture3D::storage"); - if(w==0 || h==0 || d==0) + if(wd==0 || ht==0 || dp==0) throw invalid_argument("Texture3D::storage"); - width = w; - height = h; - depth = d; - ifmt = f; + width = wd; + height = ht; + depth = dp; + ifmt = fmt; } void Texture3D::allocate(unsigned level) diff --git a/source/texture3d.h b/source/texture3d.h index 12bd4a4b..0a03cd5d 100644 --- a/source/texture3d.h +++ b/source/texture3d.h @@ -9,6 +9,10 @@ namespace Msp { namespace GL { +/** +Three-dimensional texture. Consists of an array of texels in the shape of a +right cuboid. Texture coordinates have a principal range of [0, 1]. +*/ class Texture3D: public Texture { private: @@ -20,11 +24,37 @@ private: public: Texture3D(); - void storage(PixelFormat, unsigned, unsigned, unsigned); - void allocate(unsigned); - void image(unsigned, PixelFormat, DataType, const void *); - void sub_image(unsigned, int, int, int, unsigned, unsigned, unsigned, PixelFormat, DataType, const void *); + + /** Defines storage structure for the texture. Must be called before an + image can be uploaded. Once storage is defined, it can't be changed. */ + void storage(PixelFormat fmt, unsigned wd, unsigned ht, unsigned dp); + + /** Allocates storage for the texture. The contents are initially + undefined. If storage has already been allocated, does nothing. */ + void allocate(unsigned level); + + /** Uploads an image to the texture. Storage must be defined beforehand. + The image data must have dimensions and format compatible with the defined + storage. */ + void image(unsigned level, PixelFormat fmt, DataType type, const void *data); + + /** Updates a cuboid-shaped region of the texture. Storage must be defined + and allocated beforehand. The update region must be fully inside the + texture. */ + void sub_image(unsigned level, + int x, int y, int z, unsigned wd, unsigned ht, unsigned dp, + PixelFormat fmt, DataType type, const void *data); + + /** Loads an image from a file and uploads it to the texture. If storage + has not been defined, it will be set to match the loaded image. To + construct a three-dimensional texture from a two-dimensional image, the + image is interpreted as an array of consecutive images. If dp is -1, the + texture's width and height are equal. If dp is -2, the texture's height and + depth are equal. Otherwise, dp must be positive and determines the + texture's depth. In all cases, the image's height must equal the texture's + height times its depth. */ void load_image(const std::string &fn, int dp = -1); + unsigned get_width() const { return width; } unsigned get_height() const { return height; } unsigned get_depth() const { return depth; } diff --git a/source/texturecube.h b/source/texturecube.h index c8e18a11..b15c1cff 100644 --- a/source/texturecube.h +++ b/source/texturecube.h @@ -21,8 +21,9 @@ enum TextureCubeFace /** Cube map texture, consisting of six square faces. All of the faces must be of the same size. A cube map texture is addressed by three-dimensional texture -coordinates. The face is first selected according to the largest coordinate, -and the remaining two coordinates are used to sample the face image. +coordinates, with a principal range of [-1, 1]. The face is first selected +according to the largest coordinate, and the remaining two coordinates are used +to sample the face image. All faces of a cube map texture must be allocated for it to be usable.