| Name |
| |
| AMD_framebuffer_multisample_advanced |
| |
| Name Strings |
| |
| GL_AMD_framebuffer_multisample_advanced |
| |
| Contact |
| |
| Marek Olsak, AMD (marek.olsak 'at' amd.com) |
| |
| Status |
| |
| Complete. |
| |
| Version |
| |
| Last Modified Date: June 28, 2018 |
| Revision #1 |
| |
| Number |
| |
| OpenGL Extension #523 |
| OpenGL ES Extension #303 |
| |
| Dependencies |
| |
| OpenGL dependencies: |
| |
| Requires GL_ARB_framebuffer_object. |
| |
| OpenGL ES dependencies: |
| |
| Requires OpenGL ES 3.0. |
| |
| This extension is written against the OpenGL 4.5 (Core Profile) |
| specification. |
| |
| Overview |
| |
| This extension extends ARB_framebuffer_object by allowing compromises |
| between image quality and memory footprint of multisample |
| antialiasing. |
| |
| ARB_framebuffer_object introduced RenderbufferStorageMultisample |
| as a method of defining the parameters for a multisample render |
| buffer. This function takes a <samples> parameter that has strict |
| requirements on behavior such that no compromises in the final image |
| quality are allowed. Additionally, ARB_framebuffer_object requires |
| that all framebuffer attachments have the same number of samples. |
| |
| This extension extends ARB_framebuffer_object by providing a new |
| function, RenderbufferStorageMultisampleAdvancedAMD, that |
| distinguishes between samples and storage samples for color |
| renderbuffers where the number of storage samples can be less than |
| the number of samples. This extension also allows non-matching sample |
| counts between color and depth/stencil renderbuffers. |
| |
| This extension does not require any specific combination of sample |
| counts to be supported. |
| |
| IP Status |
| |
| No known IP issues. |
| |
| New Procedures and Functions |
| |
| void RenderbufferStorageMultisampleAdvancedAMD( |
| enum target, sizei samples, sizei storageSamples, |
| enum internalformat, sizei width, sizei height ); |
| |
| void NamedRenderbufferStorageMultisampleAdvancedAMD( |
| uint renderbuffer, sizei samples, sizei storageSamples, |
| enum internalformat, sizei width, sizei height ); |
| |
| New Tokens |
| |
| Accepted by the <pname> parameter of GetRenderbufferParameteriv: |
| |
| RENDERBUFFER_STORAGE_SAMPLES_AMD 0x91B2 |
| |
| Accepted by the <pname> parameter of GetBooleanv, GetIntegerv, |
| GetInteger64v, GetFloatv, GetDoublev: |
| |
| MAX_COLOR_FRAMEBUFFER_SAMPLES_AMD 0x91B3 |
| MAX_COLOR_FRAMEBUFFER_STORAGE_SAMPLES_AMD 0x91B4 |
| MAX_DEPTH_STENCIL_FRAMEBUFFER_SAMPLES_AMD 0x91B5 |
| NUM_SUPPORTED_MULTISAMPLE_MODES_AMD 0x91B6 |
| SUPPORTED_MULTISAMPLE_MODES_AMD 0x91B7 |
| |
| Additions to Chapter 9 of the OpenGL 4.5 (Core Profile) Specification |
| (Framebuffers and Framebuffer Objects) |
| |
| In section 9.2.3.1, "Multisample Queries", remove the last paragraph |
| beginning with "Otherwise" and add: |
| |
| Otherwise, the value of SAMPLES is equal to the value of |
| RENDERBUFFER_SAMPLES or TEXTURE_SAMPLES (depending on the type of |
| attachments) of color attachments if any is present. If there is no |
| color attachment, SAMPLES is equal to the same value from the depth or |
| stencil attachment, whichever is present. |
| |
| An implementation may only support a subset of the possible |
| combinations of sample counts of textures and renderbuffers attached |
| to a framebuffer object. The number of supported combinations is |
| NUM_SUPPORTED_MULTISAMPLE_MODES_AMD. SUPPORTED_MULTISAMPLE_MODES_AMD |
| is an array of NUM_SUPPORTED_MULTISAMPLE_MODES_AMD triples of integers |
| where each triple contains a valid combination of sample counts in |
| the form {color samples, color storage samples, depth and stencil |
| samples}. The first element in each triple is at least 2. The second |
| and third element in each triple are at least 1 and are not greater |
| than the first element. |
| |
| In section 9.2.4, "Renderbuffer Objects", replace the description of |
| (Named)RenderbufferStorageMultisample: |
| |
| The data storage, format, dimensions, number of samples, and number of |
| storage samples of a renderbuffer object’s image are established with |
| the commands |
| |
| void RenderbufferStorageMultisampleAdvancedAMD( enum target, |
| sizei samples, sizei storageSamples, enum internalformat, |
| sizei width, sizei height ); |
| |
| void NamedRenderbufferStorageMultisampleAdvancedAMD( |
| uint renderbuffer, sizei samples, sizei storageSamples, |
| enum internalformat, sizei width, sizei height ); |
| |
| For RenderbufferStorageMultisampleAdvancedAMD, the renderbuffer object |
| is that bound to <target>, which must be RENDERBUFFER. |
| For NamedRenderbufferStorageMultisampleAdvancedAMD, <renderbuffer> is |
| the name of the renderbuffer object. |
| |
| <internalformat> must be color-renderable, depth-renderable, or |
| stencil-renderable (as defined in section 9.4). <width> and <height> |
| are the dimensions in pixels of the renderbuffer. |
| |
| Upon success, *RenderbufferStorageMultisampleAdvancedAMD deletes any |
| existing data store for the renderbuffer image, and the contents of |
| the data store are undefined. RENDERBUFFER_WIDTH is set to <width>, |
| RENDERBUFFER_HEIGHT is set to <height>, and RENDERBUFFER_INTERNAL_- |
| FORMAT is set to <internalformat>. |
| |
| If <samples> is zero, then <storageSamples> must be zero, and |
| RENDERBUFFER_SAMPLES and RENDERBUFFER_STORAGE_SAMPLES_AMD are set to |
| zero. Otherwise <samples> represents a request for a desired minimum |
| number of samples and <storageSamples> represents a request for |
| a desired minimum number of storage samples, where <storageSamples> |
| must not be greater than <samples>. Since different implementations |
| may support different sample counts for multisampled rendering, |
| the actual number of samples and the actual number of storage samples |
| allocated for the renderbuffer image are implementation-dependent. |
| However, the resulting value for RENDERBUFFER_SAMPLES is guaranteed |
| to be greater than or equal to <samples> and no more than the next |
| larger sample count supported by the implementation, and the resulting |
| value for RENDERBUFFER_STORAGE_SAMPLES_AMD is guaranteed to be greater |
| than or equal to <storageSamples>, no more than the next larger |
| storage sample count supported by the implementation, and no more than |
| RENDERBUFFER_SAMPLES. |
| |
| A GL implementation may vary its allocation of internal component |
| resolution based on any *RenderbufferStorageMultisampleAdvancedAMD |
| parameter (except <target> and <renderbuffer>), but the allocation and |
| chosen internal format must not be a function of any other state and |
| cannot be changed once they are established. |
| |
| Remove the first 4 errors and add these errors: |
| |
| An INVALID_ENUM error is generated by RenderbufferStorageMultisample- |
| AdvancedAMD if <target> is not RENDERBUFFER. |
| |
| An INVALID_OPERATION error is generated by NamedRenderbufferStorage- |
| MultisampleAdvancedAMD if <renderbuffer> is not the name of |
| an existing renderbuffer object. |
| |
| An INVALID_VALUE error is generated if <samples>, <storageSamples>, |
| <width>, or <height> is negative. |
| |
| An INVALID_OPERATION error is generated if <internalformat> is a color |
| format and <samples> is greater than the implementation-dependent |
| limit MAX_COLOR_FRAMEBUFFER_SAMPLES_AMD. |
| |
| An INVALID_OPERATION error is generated if <internalformat> is a color |
| format and <storageSamples> is greater than the implementation- |
| dependent limit MAX_COLOR_FRAMEBUFFER_STORAGE_SAMPLES_AMD. |
| |
| An INVALID_OPERATION error is generated if <storageSamples> is greater |
| than <samples>. |
| |
| An INVALID_OPERATION error is generated if <internalformat> is a depth |
| or stencil format and <samples> is greater than the maximum number of |
| samples supported for <internalformat> (see GetInternalformativ |
| in section 22.3). |
| |
| An INVALID_OPERATION error is generated if <internalformat> is a depth |
| or stencil format and <storageSamples> is not equal to <samples>. |
| |
| Finish the section as follows: |
| |
| The commands |
| |
| void RenderbufferStorageMultisample( enum target, |
| sizei samples, enum internalformat, sizei width, |
| sizei height ); |
| void RenderbufferStorage( enum target, enum internalformat, |
| sizei width, sizei height ); |
| |
| are equivalent to |
| |
| RenderbufferStorageMultisampleAdvancedAMD(target, samples, |
| samples, internalformat, width, height); |
| |
| and |
| |
| RenderbufferStorageMultisampleAdvancedAMD(target, 0, 0, |
| internalformat, width, height); |
| |
| respectively. |
| |
| The commands |
| |
| void NamedRenderbufferStorageMultisample( uint renderbuffer, |
| sizei samples, enum internalformat, sizei width, |
| sizei height ); |
| void NamedRenderbufferStorage( uint renderbuffer, |
| enum internalformat, sizei width, sizei height ); |
| |
| are equivalent to |
| |
| NamedRenderbufferStorageMultisampleAdvancedAMD(renderbuffer, |
| samples, samples, internalformat, width, height); |
| |
| and |
| |
| NamedRenderbufferStorageMultisampleAdvancedAMD(renderbuffer, |
| 0, 0, internalformat, width, height); |
| |
| respectively. |
| |
| In section 9.2.5, "Required Renderbuffer Formats", replace the last |
| paragraph with: |
| |
| Implementations must support creation of renderbuffers in these |
| required formats with sample counts up to and including: |
| * MAX_COLOR_FRAMEBUFFER_SAMPLES_AMD as color renderbuffer samples |
| * MAX_COLOR_FRAMEBUFFER_STORAGE_SAMPLES_AMD as color renderbuffer |
| storage samples |
| * MAX_DEPTH_STENCIL_FRAMEBUFFER_SAMPLES_AMD as depth and stencil |
| samples |
| |
| with the exception that the signed and unsigned integer formats are |
| required only to support creation of renderbuffers with up to |
| the value of MAX_INTEGER_SAMPLES samples and storage samples, which |
| must be at least one. |
| |
| In section 9.2.6, "Renderbuffer Object Queries", replace the paragraph |
| mentioning RENDERBUFFER_SAMPLES with: |
| |
| If <pname> is RENDERBUFFER_WIDTH, RENDERBUFFER_HEIGHT, |
| RENDERBUFFER_INTERNAL_FORMAT, RENDERBUFFER_SAMPLES, or |
| RENDERBUFFER_STORAGE_SAMPLES_AMD then <params> will contain the width |
| in pixels, height in pixels, internal format, number of samples, or |
| number of storage samples, respectively, of the image of |
| the renderbuffer object. |
| |
| In section 9.4.1, "Framebuffer Attachment Completeness", remove |
| the bullet beginning with "If <image> has multisample samples" and |
| replace the last 3 bullets about <attachment> with: |
| |
| If <attachment> is COLOR_ATTACHMENTi, then <image> must have a color- |
| renderable internal format, the sample count must be less than or |
| equal to the value of the implementation-dependent limit |
| MAX_COLOR_FRAMEBUFFER_SAMPLES_AMD, and the storage sample count must |
| be less than or equal to the value of the implementation-dependent |
| limit MAX_COLOR_FRAMEBUFFER_STORAGE_SAMPLES_AMD. |
| |
| If <attachment> is DEPTH_ATTACHMENT, then <image> must have a depth- |
| renderable internal format, and its sample count must be less than or |
| equal to the value of the implementation-dependent limit |
| MAX_DEPTH_STENCIL_FRAMEBUFFER_SAMPLES_AMD. |
| |
| If <attachment> is STENCIL_ATTACHMENT, then <image> must have |
| a stencil-renderable internal format, and its sample count must be |
| less than or equal to the value of the implementation-dependent limit |
| MAX_DEPTH_STENCIL_FRAMEBUFFER_SAMPLES_AMD. |
| |
| In section 9.4.2, replace the bullet mentioning RENDERBUFFER_SAMPLES |
| with: |
| |
| * The value of RENDERBUFFER_SAMPLES of a color attachment defines its |
| <number of color samples>; the value of RENDERBUFFER_STORAGE_SAMPLES |
| of a color attachment defines its <number of color storage samples>; |
| the value of RENDERBUFFER_SAMPLES of a depth or stencil attachment |
| defines its <number of depth-stencil samples> for each separately; |
| the value of TEXTURE_SAMPLES of a color attachment defines both its |
| <number of color samples> and its <number of color storage samples>; |
| the value of TEXTURE_SAMPLES of a depth or stencil attachment defines |
| its <number of depth-stencil samples> for each separately. If any of |
| the defined values is 0, it is treated as 1. Any undefined value is |
| treated as equal to any number. For all attachment values that are |
| defined, all values of <number of color samples> must be equal, all |
| values of <number of color storage samples> must be equal, all values |
| of <number of depth-stencil samples> must be equal, and the triple |
| {<number of color samples>, <number of color storage samples>, <number |
| of depth-stencil samples>} must be in SUPPORTED_MULTISAMPLE_MODES_AMD |
| or must be equal to {1, 1, 1}. |
| |
| { FRAMEBUFFER_INCOMPLETE_MULTISAMPLE } |
| |
| Additions to Chapter 17 of the OpenGL 4.5 (Core Profile) Specification |
| (Writing Fragments and Samples to the Framebuffer) |
| |
| In section 17.3.10, "Additional Multisample Fragment Operations", add |
| this paragraph after the "If MULTISAMPLE is enabled" paragraph: |
| |
| If there are fewer color storage samples (see section 9.2.4) than |
| the value of SAMPLES, the number of color storage samples determines |
| the number of unique color values that can be stored per pixel. |
| The implementation must determine which samples within a pixel share |
| the same color value, write that value into 1 color storage sample, |
| and remember a mapping between color samples and color storage |
| samples to be able to map color storage samples back to color samples. |
| The color value equality determination is done in an implementation- |
| specific manner, but the implementation must at least recognize a set |
| of color samples coming from the same primitive as 1 storage sample if |
| sample shading (see section 14.3.1.1) is disabled. If there are not |
| enough color storage samples per pixel to store all incoming color |
| values, the excessive color values are not stored and the color samples |
| with unstored values are marked as having an unknown value. Color |
| samples with an unknown value will not contribute to the final color |
| value of the pixel when all color samples are resolved by |
| BlitFramebuffer (see section 18.3.1). |
| |
| If there are fewer depth and stencil samples than the value of SAMPLES |
| and implementation-specific optimizations are unable to represent more |
| depth and stencil samples within the given storage, the missing depth |
| and stencil values should be pulled from or derived from the nearest |
| existing depth and stencil samples within the same pixel. The mapping |
| from missing to existing depth and stencil samples is implementation- |
| specific, but the mapping must be at least: |
| * injective if missing samples < existing samples |
| * bijective if missing samples = existing samples |
| * surjective if missing samples > existing samples |
| Depth and stencil tests operate as if the number of depth and stencil |
| samples was equal to the value of SAMPLES. |
| |
| Errors |
| |
| An INVALID_ENUM error is generated by RenderbufferStorageMultisample- |
| AdvancedAMD if <target> is not RENDERBUFFER. |
| |
| An INVALID_OPERATION error is generated by NamedRenderbufferStorage- |
| MultisampleAdvancedAMD if <renderbuffer> is not the name of |
| an existing renderbuffer object. |
| |
| An INVALID_VALUE error is generated if <samples>, <storageSamples>, |
| <width>, or <height> is negative. |
| |
| An INVALID_OPERATION error is generated if <internalformat> is a color |
| format and <samples> is greater than the implementation-dependent |
| limit MAX_COLOR_FRAMEBUFFER_SAMPLES_AMD. |
| |
| An INVALID_OPERATION error is generated if <internalformat> is a color |
| format and <storageSamples> is greater than the implementation- |
| dependent limit MAX_COLOR_FRAMEBUFFER_STORAGE_SAMPLES_AMD. |
| |
| An INVALID_OPERATION error is generated if <storageSamples> is greater |
| than <samples>. |
| |
| An INVALID_OPERATION error is generated if <internalformat> is a depth |
| or stencil format and <samples> is greater than the maximum number of |
| samples supported for <internalformat> (see GetInternalformativ |
| in section 22.3). |
| |
| An INVALID_OPERATION error is generated if <internalformat> is a depth |
| or stencil format and <storageSamples> is not equal to <samples>. |
| |
| New State |
| |
| Add to Table 23.27, "Renderbuffer (state per renderbuffer object)" |
| Initial |
| Get Value Type Get Command Value Description Section |
| -------------------------------- ---- -------------------------- ------- ---------------------- ------- |
| RENDERBUFFER_STORAGE_SAMPLES_AMD Z+ GetRenderbufferParameteriv 0 No. of storage samples 9.2.4 |
| |
| New Implementation Dependent Values |
| Minimum |
| Get Value Type Get Command Value Description Section |
| ---------------------------------------- ---------- ----------- ------- --------------------------------------- ------- |
| MAX_COLOR_FRAMEBUFFER_SAMPLES_AMD Z+ GetIntegerv 4 Max. no. of color samples supported by 9.2.4 |
| framebuffer objects. |
| MAX_COLOR_FRAMEBUFFER_STORAGE_SAMPLES_AMD Z+ GetIntegerv 4 Max. no. of color storage samples 9.2.4 |
| supported by framebuffer objects. |
| MAX_DEPTH_STENCIL_FRAMEBUFFER_SAMPLES_AMD Z+ GetIntegerv 4 Max. no. of depth and stencil samples 9.2.4 |
| supported by framebuffer objects. |
| NUM_SUPPORTED_MULTISAMPLE_MODES_AMD Z+ GetIntegerv 1 No. of supported combinations of color 9.2.4 |
| samples, color storage samples, and |
| depth-stencil samples by framebuffer |
| objects. |
| SUPPORTED_MULTISAMPLE_MODES_AMD n * 3 x Z+ GetIntegerv - NUM_SUPPORTED_MULTISAMPLE_MODES_AMD (n) 9.2.4 |
| triples of integers. Each triple is |
| a unique combination of color samples, |
| color storage samples, and depth-stencil |
| samples supported by framebuffer objects. |
| |
| AMD Implementation Details |
| |
| The following multisample modes are supported by AMD's open source |
| OpenGL driver: |
| |
| Color Depth & |
| Color storage stencil |
| samples samples samples |
| ======= ======= ======= |
| 16 8 8 |
| 16 4 8 |
| 16 2 8 |
| 16 4 4 |
| 16 2 4 |
| 16 2 2 |
| ------- ------- ------- |
| 8 8 8 |
| 8 4 8 |
| 8 2 8 |
| 8 4 4 |
| 8 2 4 |
| 8 2 2 |
| ------- ------- ------- |
| 4 4 4 |
| 4 2 4 |
| 4 2 2 |
| ------- ------- ------- |
| 2 2 2 |
| |
| Issues |
| |
| None. |
| |
| Revision History |
| |
| Rev. Date Author Changes |
| ---- -------- -------- -------------------------------------------- |
| 1 06/28/18 mareko Initial version |
