| Name |
| |
| EXT_copy_texture |
| |
| Name Strings |
| |
| GL_EXT_copy_texture |
| |
| Version |
| |
| $Date: 1995/06/17 03:33:42 $ $Revision: 1.21 $ |
| |
| Number |
| |
| 10 |
| |
| Dependencies |
| |
| EXT_texture is required. |
| EXT_texture3D affects the definition of this extension. |
| SGIS_texture_filter4 affects the definition of this extension. |
| EXT_subtexture affects the definition of this extension. |
| |
| Overview |
| |
| This extension defines methods to load texture images directly from the |
| framebuffer. Methods are defined for both complete and partial |
| replacement of a texture image. Because it is not possible to define |
| an entire 3D texture using a 2D framebuffer image, 3D textures are |
| supported only for partial replacement. |
| |
| New Procedures and Functions |
| |
| void CopyTexImage1DEXT(enum target, |
| int level, |
| enum internalformat, |
| int x, |
| int y, |
| sizei width, |
| int border); |
| |
| void CopyTexImage2DEXT(enum target, |
| int level, |
| enum internalformat, |
| int x, |
| int y, |
| sizei width, |
| sizei height, |
| int border); |
| |
| void CopyTexSubImage1DEXT(enum target, |
| int level, |
| int xoffset, |
| int x, |
| int y, |
| sizei width); |
| |
| void CopyTexSubImage2DEXT(enum target, |
| int level, |
| int xoffset, |
| int yoffset, |
| int x, |
| int y, |
| sizei width, |
| sizei height); |
| |
| void CopyTexSubImage3DEXT(enum target, |
| int level, |
| int xoffset, |
| int yoffset, |
| int zoffset, |
| int x, |
| int y, |
| sizei width, |
| sizei height); |
| |
| New Tokens |
| |
| None |
| |
| Additions to Chapter 2 of the 1.0 Specification (OpenGL Operation) |
| |
| None |
| |
| Additions to Chapter 3 of the 1.0 Specification (Rasterization) |
| |
| CopyTexImage1DEXT and CopyTexImage2DEXT are related to TexImage1D and |
| TexImage2D in exactly the way that CopyPixels is related to DrawPixels. |
| Rather than accepting image data from memory, they copy image data from |
| the color buffer specified by the current ReadBuffer mode. |
| CopyTexImage2DEXT accepts image data from a width+2*border pixel wide by |
| height+2*border pixel high color buffer region whose lower-left pixel |
| has window coordinates <x>,<y>. If any pixels within this region are |
| outside the window that is associated with the GL context, the values |
| obtained for those pixels are undefined. These pixel values are |
| processed exactly as if CopyPixels had been called, but the process |
| stops just before final conversion. Subsequent processing is exactly |
| as though TexImage2D had be called, beginning with the clamping of the |
| pixel group components to [0,1]. Pixel ordering is such that lower X |
| screen coordinates correspond to lower i texture coordinates, and lower |
| Y screen coordinates correspond to lower j texture coordinates (refer to |
| Figure 3.10 - A texture image and the coordinates used to access it, GL |
| Specification). The semantics and accepted values of the <target>, |
| <level>, and <border> parameters are exactly equivalent to their |
| TexImage2D counterparts, except that <target> does not accept |
| PROXY_TEXTURE_2D_EXT. The semantics of <internalformat> are identical |
| to those of the <components> parameter of TexImage2D, except that |
| values 1, 2, 3, and 4 are not accepted by CopyTexImage2DEXT. |
| |
| CopyTexImage1DEXT accepts image data from a width+2*border pixel wide |
| by 1 pixel high color buffer region whose left-most pixel has window |
| coordinates <x>,<y>. If any pixels within this region are outside the |
| window that is associated with the GL context, the values obtained for |
| those pixels are undefined. The pixels are processed just as those of |
| CopyTexImage2DEXT are, and they define a texture such that lower X |
| window coordinates correspond to lower i texture coordinates, as per |
| Figure 3.10 of the GL Specification. The semantics and accepted values |
| of the <level>, <border>, and <internalformat> parameters are exactly |
| those of CopyTexImage2DEXT. <target> accepts only TEXTURE_1D. |
| |
| If EXT_subtexture is supported, this extension also defines |
| CopyTexSubImage1DEXT and CopyTexSubImage2DEXT. These commands are |
| related to TexSubImage1DEXT and TexSubImage2DEXT in exactly the way |
| that CopyPixels is related to DrawPixels. Rather than accepting image |
| data from memory, they copy image data from the framebuffer. The |
| semantics and accepted values of the <target>, <level>, <xoffset>, and |
| <yoffset> parameters are exactly equivalent to their TexSubImage1DEXT |
| and TexSubImage2DEXT counterparts. The semantics and accepted values |
| of the <x>, <y>, <width>, and <height> parameters are exactly equivalent |
| to their CopyTexImage1DEXT and CopyTexImage2DEXT counterparts. |
| |
| If EXT_subtexture and EXT_texture3D are both supported, this extension |
| also defines CopyTexSubImage3DEXT. Because framebuffer memory is two- |
| dimensional, only a portion of a single s,t slice of a 3D texture is |
| replaced by this command. Thus CopyTexSubImage3DEXT is related to |
| TexSubImage3DEXT in exactly the way that CopyPixels is related to |
| DrawPixels, except that it is as though TexSubImage3DEXT parameter |
| <depth> were 1. Rather than accepting image data from memory, |
| CopyTexSubImage3DEXT copies image data from the framebuffer. The |
| semantics and accepted values of the <target>, <level>, <xoffset>, |
| <yoffset>, and <zoffset> parameters are exactly equivalent to their |
| TexSubImage3DEXT counterparts. The semantics and accepted values of |
| the <x>, <y>, <width>, and <height> parameters are exactly equivalent |
| to their CopyTexImage2DEXT counterparts. |
| |
| Additions to Chapter 4 of the 1.0 Specification (Per-Fragment Operations |
| and the Framebuffer) |
| |
| None |
| |
| Additions to Chapter 5 of the 1.0 Specification (Special Functions) |
| |
| None |
| |
| Additions to Chapter 6 of the 1.0 Specification (State and State Requests) |
| |
| None |
| |
| Additions to the GLX Specification |
| |
| None |
| |
| GLX Protocol |
| |
| Five new GL rendering commands are added. The following commands are sent to the |
| server as part of a glXRender request: |
| |
| CopyTexImage1DEXT |
| 2 32 rendering command length |
| 2 4119 rendering command opcode |
| 4 ENUM target |
| 4 INT32 level |
| 4 ENUM internalformat |
| 4 INT32 x |
| 4 INT32 y |
| 4 INT32 width |
| 4 INT32 border |
| |
| CopyTexImage2DEXT |
| 2 36 rendering command length |
| 2 4120 rendering command opcode |
| 4 ENUM target |
| 4 INT32 level |
| 4 ENUM internalformat |
| 4 INT32 x |
| 4 INT32 y |
| 4 INT32 width |
| 4 INT32 height |
| 4 INT32 border |
| |
| CopyTexSubImage1DEXT |
| 2 28 rendering command length |
| 2 4121 rendering command opcode |
| 4 ENUM target |
| 4 INT32 level |
| 4 INT32 xoffset |
| 4 INT32 x |
| 4 INT32 y |
| 4 INT32 width |
| |
| CopyTexSubImage2DEXT |
| 2 36 rendering command length |
| 2 4122 rendering command opcode |
| 4 ENUM target |
| 4 INT32 level |
| 4 INT32 xoffset |
| 4 INT32 yoffset |
| 4 INT32 x |
| 4 INT32 y |
| 4 INT32 width |
| 4 INT32 height |
| |
| CopyTexSubImage3DEXT |
| 2 40 rendering command length |
| 2 4123 rendering command opcode |
| 4 ENUM target |
| 4 INT32 level |
| 4 INT32 xoffset |
| 4 INT32 yoffset |
| 4 INT32 zoffset |
| 4 INT32 x |
| 4 INT32 y |
| 4 INT32 width |
| 4 INT32 height |
| |
| Dependencies on EXT_texture |
| |
| EXT_texture is required. This extension builds on the notion of |
| internal image format, which is defined by EXT_texture. |
| |
| Dependencies on EXT_texture3D |
| |
| If EXT_texture3D is not supported, CopyTexSubImage3DEXT is not defined |
| by this extension. |
| |
| Dependencies on SGIS_texture_filter4 |
| |
| If SGIS_texture_filter4 is not supported, 2 is not accepted as a border |
| value. |
| |
| Dependencies on EXT_subtexture |
| |
| If EXT_subtexture is not supported, CopyTexSubImage1DEXT, |
| CopyTexSubImage2DEXT, and CopyTexSubImage3DEXT are not defined by this |
| extension. |
| |
| Errors |
| |
| INVALID_ENUM is generated if CopyTexImage1DEXT or CopyTexSubImage1DEXT |
| parameter <target> is not TEXTURE_1D. (The commands defined by this |
| extension do not accept PROXY targets.) |
| |
| INVALID_ENUM is generated if CopyTexImage2DEXT or CopyTexSubImage2DEXT |
| parameter <target> is not TEXTURE_2D. |
| |
| INVALID_ENUM is generated if CopyTexSubImage3DEXT parameter <target> |
| is not TEXTURE_3D_EXT. |
| |
| INVALID_VALUE is generated if CopyTexImage1DEXT or CopyTexImage2DEXT |
| parameter <level> is less than zero, or greater than the maximum value |
| supported by the implementation. |
| |
| INVALID_ENUM is generated if CopyTexImage1DEXT or CopyTexImage2DEXT |
| parameter <internalformat> is not ALPHA, RGB, RGBA, LUMINANCE, |
| LUMINANCE_ALPHA, or one of the token values defined by EXT_texture. |
| |
| INVALID_VALUE is generated when any of the <width> or <height> |
| parameters of CopyTexImage1DEXT or CopyTexImage2DEXT is less than zero, |
| or if it cannot be represented as 2**k + 2*border for some integer k. |
| |
| INVALID_VALUE is generated if CopyTexSubImage1DEXT, CopyTexSubImage2DEXT, |
| or CopyTexSubImage3DEXT parameter <xoffset>, CopyTexSubImage2DEXT or |
| CopyTexSubImage3DEXT parameter <yoffset>, or CopyTexSubImage3DEXT |
| parameter <zoffset> is less than -TEXTURE_BORDER, where TEXTURE_BORDER |
| is the border width of the texture array to be modified. |
| |
| INVALID_VALUE is generated if CopyTexSubImage1DEXT, CopyTexSubImage2DEXT, |
| or CopyTexSubImage3DEXT (xoffset + width) > (TEXTURE_WIDTH - |
| TEXTURE_BORDER), or if CopyTexSubImage2DEXT or CopyTexSubImage3DEXT |
| (yoffset + height) > (TEXTURE_HEIGHT - TEXTURE_BORDER), or if |
| CopyTexSubImage3DEXT zoffset >= (TEXTURE_DEPTH_EXT - TEXTURE_BORDER). |
| Note that TEXTURE_WIDTH, TEXTURE_HEIGHT, and TEXTURE_DEPTH_EXT include |
| twice the border width. |
| |
| TEXTURE_TOO_LARGE_EXT is generated by CopyTexImage1DEXT or |
| CopyTexImage2DEXT if the specified image is too large, for any reason. |
| (See EXT_texture for a discussion of how applications can query the |
| maximum texture size.) |
| |
| INVALID_VALUE is generated if CopyTexImage1DEXT or CopyTexImage2DEXT |
| parameter <border> is not 0, 1, or 2. |
| |
| INVALID_OPERATION is generated if CopyTexImage1DEXT, CopyTexImage2DEXT, |
| CopyTexSubImage1DEXT, CopyTexSubImage2DEXT, or CopyTexSubImage3DEXT is |
| called between execution of Begin and the corresponding execution of |
| End. |
| |
| New State |
| |
| None |
| |
| New Implementation Dependent State |
| |
| None |
