| Name |
| |
| ANGLE_get_tex_level_parameter |
| |
| Name Strings |
| |
| GL_ANGLE_get_tex_level_parameter |
| |
| Contributors |
| |
| Geoff Lang, Google |
| |
| Contact |
| |
| Geoff Lang (geofflang 'at' google.com) |
| |
| Status |
| |
| Incomplete |
| |
| Version |
| |
| Last Modified Date: Oct 12, 2020 |
| Author Revision: 1 |
| |
| Number |
| |
| OpenGL ES Extension XX |
| |
| Dependencies |
| |
| OpenGL ES 2.0 is required. |
| |
| This extension is written against the OpenGL ES 3.0.5 specification. |
| |
| Overview |
| |
| This extension allows the user to query information about specific texture |
| levels exposed later in OpenGL ES 3.1. |
| |
| IP Status |
| |
| No known IP claims. |
| |
| New Procedures and Functions |
| |
| void GetTexLevelParameter{if}vANGLE(enum target, int level, |
| enum pname, T *params ); |
| |
| New Tokens |
| |
| Accepted by the <pname> parameter of GetTexLevelParameter{if}vANGLE: |
| |
| TEXTURE_WIDTH 0x1000 |
| TEXTURE_HEIGHT 0x1001 |
| TEXTURE_DEPTH 0x8071 |
| TEXTURE_INTERNAL_FORMAT 0x1003 |
| TEXTURE_RED_SIZE 0x805C |
| TEXTURE_GREEN_SIZE 0x805D |
| TEXTURE_BLUE_SIZE 0x805E |
| TEXTURE_ALPHA_SIZE 0x805F |
| TEXTURE_DEPTH_SIZE 0x884A |
| TEXTURE_STENCIL_SIZE 0x88F1 |
| TEXTURE_SHARED_SIZE 0x8C3F |
| TEXTURE_RED_TYPE 0x8C10 |
| TEXTURE_GREEN_TYPE 0x8C11 |
| TEXTURE_BLUE_TYPE 0x8C12 |
| TEXTURE_ALPHA_TYPE 0x8C13 |
| TEXTURE_DEPTH_TYPE 0x8C16 |
| TEXTURE_COMPRESSED 0x86A1 |
| |
| Additions to Chapter 6 of the OpenGL ES 3.0.5 Specification (State and State |
| Requests) |
| |
| Modify Section 6.1.4 "Texture Queries": |
| |
| (Add the following text to the end of the section) |
| |
| The commands |
| |
| void GetTexLevelParameter{if}vANGLE(enum target, int level, |
| enum pname, T *params ); |
| |
| place information about texture image parameter <pname> for level-of-detail |
| <level> of the specified target into <params>. <pname> must be one of the |
| symbolic values in table 6.11. |
| |
| <target> may be one of TEXTURE_2D or one of the cube map face targets from |
| table 3.18, indicating the two-dimensional texture or one of the six distinct |
| 2D images making up the cube map texture object. Otherwise an INVALID_ENUM is |
| generated. |
| |
| <level> determines which level-of-detail's state is returned. If <level> |
| is negative or larger than the maximum allowable level-of-detail, then an |
| INVALID_VALUE error is generated. |
| |
| Note that TEXTURE_CUBE_MAP is not a valid <target> parameter for |
| GetTexLevelParameter{if}vANGLE, because it does not specify a particular |
| cube map face. |
| |
| For texture images with uncompressed internal formats, queries of |
| <pname> TEXTURE_RED_TYPE, TEXTURE_GREEN_TYPE, TEXTURE_BLUE_TYPE, |
| TEXTURE_ALPHA_TYPE, and TEXTURE_DEPTH_TYPE return the data type used |
| to store the component. Types NONE, SIGNED_NORMALIZED, UNSIGNED_- |
| NORMALIZED, FLOAT, INT, and UNSIGNED_INT respectively indicate missing, |
| signed normalized fixed-point, unsigned normalized fixed-point, |
| floating-point, signed unnormalized integer, and unsigned unnormalized |
| integer components. Queries of <pname> TEXTURE_RED_SIZE, TEXTURE_GREEN_SIZE, |
| TEXTURE_BLUE_SIZE, TEXTURE_ALPHA_SIZE, TEXTURE_DEPTH_SIZE, |
| TEXTURE_STENCIL_SIZE, and TEXTURE_SHARED_SIZE return the actual resolutions |
| of the stored image components, not the resolutions specified when the image |
| was defined. Invalid <pname> generate an INVALID_ENUM error. |
| |
| For texture images with compressed internal formats, the types returned |
| specify how components are interpreted after decompression, while the |
| resolutions returned specify the component resolution of an uncompressed |
| internal format that produces an image of roughly the same quality as the |
| compressed image in question. Since the quality of the implementation's |
| compression algorithm is likely data-dependent, the returned component sizes |
| should be treated only as rough approximations. |
| |
| Queries of <pname> TEXTURE_INTERNAL_FORMAT, TEXTURE_WIDTH, TEXTURE_HEIGHT, |
| and TEXTURE_DEPTH return the internal format, width, height, and depth, |
| respectively, as specified when the image array was created. |
| |
| Errors |
| |
| The error INVALID_ENUM is generated by GetTexLevelParameter{if}vANGLE |
| if <target> is not one of TEXTURE_2D, TEXTURE_3D, TEXTURE_2D_ARRAY, one of |
| the cube map face targets from table 3.18, or TEXTURE_2D_MULTISAMPLE_ANGLE. |
| |
| The error INVALID_VALUE is generated by GetTexLevelParameter{if}vANGLE |
| if <level> is negative or larger than the maximum allowable level-of-detail. |
| |
| The error INVALID_ENUM is generated by GetTexLevelParameter{if}vANGLE |
| if <value> is not one of TEXTURE_RED_TYPE, TEXTURE_GREEN_TYPE, |
| TEXTURE_BLUE_TYPE, TEXTURE_ALPHA_TYPE, TEXTURE_DEPTH_TYPE, |
| TEXTURE_DEPTH_SIZE, TEXTURE_STENCIL_SIZE, TEXTURE_SHARED_SIZE, |
| TEXTURE_WIDTH, TEXTURE_HEIGHT, TEXTURE_DEPTH, TEXTURE_INTERNAL_FORMAT, |
| TEXTURE_RED_SIZE, TEXTURE_GREEN_SIZE, TEXTURE_BLUE_SIZE, TEXTURE_ALPHA_SIZE, |
| or TEXTURE_COMPRESSED. |
| |
| New State |
| |
| (add new table 6.10, Textures (state per texture image), renumber subsequent tables) |
| |
| Initial |
| Get Value Type Get Command Value Description Sec. |
| ---------------------- ---- ------------------- ------ --------------------------- ------ |
| TEXTURE_WIDTH Z+ GetTexLevelParameterANGLE 0 Specified width 3.8 |
| TEXTURE_HEIGHT Z+ GetTexLevelParameterANGLE 0 Specified height (2D/3D) 3.8 |
| TEXTURE_DEPTH Z+ GetTexLevelParameterANGLE 0 Specified depth (3D) 3.8 |
| TEXTURE_INTERNAL_FORMAT E GetTexLevelParameterANGLE RGBA Internal format 3.8 |
| or R8 (see section 3.8.14) |
| TEXTURE_x_SIZE 6xZ+ GetTexLevelParameterANGLE 0 Component resolution (x is 3.8 |
| RED, GREEN, BLUE, ALPHA, |
| DEPTH, or STENCIL) |
| TEXTURE_SHARED_SIZE Z+ GetTexLevelParameterANGLE 0 Shared exponent field 3.8 |
| resolution |
| TEXTURE_x_TYPE E GetTexLevelParameterANGLE NONE Component type (x is RED, 6.1.4 |
| GREEN, BLUE, ALPHA, or |
| DEPTH) |
| TEXTURE_COMPRESSED B GetTexLevelParameterANGLE FALSE True if image has a 3.8.6 |
| compressed internal format |
| |
| Issues |
| None |
| |
| Revision History |
| |
| Rev. Date Author Changes |
| ---- -------- ---------- -------------------------------------------- |
| 1 14/10/20 Geoff Lang First revision. Adapted from OpenGL ES |
| specification 3.1. |
