Name EXT_multiview_texture_multisample Name Strings GL_EXT_multiview_texture_multisample Contact Robert Menzel, NVIDIA Corporation (rmenzel 'at' nvidia.com) Contributors Pat Brown, NVIDIA Corporation James Helferty, NVIDIA Corporation Kedarnath Thangudu, NVIDIA Corporation Status Complete. Version Last Modified Date: May 13, 2019 Author Revision: 1 Number OpenGL Extension #537 OpenGL ES Extension #318 Dependencies OpenGL 4.0 or OpenGL ES 3.2 are required. This extension is written against the OpenGL 4.6 specification (Core Profile) (February 2, 2019) and OpenGL ES 3.2 specification (February 2, 2019). OVR_multiview is required. Overview OVR_multiview introduced multiview rendering to OpenGL and OpenGL ES. This extension removes one of the limitations of the OVR_multiview extension by allowing the use of multisample textures during multiview rendering. This is one of two extensions that allow multisampling when using OVR_multiview. Each supports one of the two different approaches to multisampling in OpenGL and OpenGL ES: Core OpenGL and OpenGL ES 3.1+ have explicit support for multisample texture types, such as TEXTURE_2D_MULTISAMPLE. Applications can access the values of individual samples and can explicitly "resolve" the samples of each pixel down to a single color. The extension EXT_multisampled_render_to_texture provides support for multisampled rendering to non-multisample texture types, such as TEXTURE_2D. The individual samples for each pixel are maintained internally by the implementation and can not be accessed directly by applications. These samples are eventually resolved implicitly to a single color for each pixel. This extension supports the first multisampling style with multiview rendering; the OVR_multiview_multisampled_render_to_texture extension supports the second style. Note that support for one of these multiview extensions does not imply support for the other. New Tokens None. New Procedures and Functions None. Modifications to Chapter 9 of the OpenGL ES 3.2 Specification as well as Chapter 9 of the OpenGL 4.6 Specification (Framebuffers and Framebuffer Objects) Modifications to all sections added and/or modified by OVR_multiview Where OVR_multiview references a "two-dimensional array texture", replace this with "two-dimensional array texture or two-dimensional multisample array texture" to explicitly allow rendering to multisampled textures. The following is an explicit list of these changes: In subsection 9.2.2.2 (introduced by OVR_multiview) replace "Finally, multiple layers of two-dimensional array textures can be attached to an attachment point." with "Finally, multiple layers of two-dimensional array textures or two-dimensional multisample array textures can be attached to an attachment point." In the additions to section 9.2.3 (Framebuffer Object Queries) replace "If is FRAMEBUFFER_ATTACHMENT_TEXTURE_NUM_VIEWS_OVR and the value of FRAMEBUFFER_ATTACHMENT_OBJECT_NAME is a two-dimensional array texture..." with "If is FRAMEBUFFER_ATTACHMENT_TEXTURE_NUM_VIEWS_OVR and the value of FRAMEBUFFER_ATTACHMENT_OBJECT_NAME is a two-dimensional array texture or a two-dimensional multisample array texture..." Also replace "If is FRAMEBUFFER_ATTACHMENT_TEXTURE_BASE_VIEW_INDEX_OVR and the value of FRAMEBUFFER_ATTACHMENT_OBJECT_NAME is a two-dimensional array texture..." with "If is FRAMEBUFFER_ATTACHMENT_TEXTURE_BASE_VIEW_INDEX_OVR and the value of FRAMEBUFFER_ATTACHMENT_OBJECT_NAME is a two-dimensional array texture or a two-dimensional multisample array texture..." In the addition to the end of section 9.2.8 (Attaching Textures to a Framebuffer) replace "Multiple layers of a two-dimensional array texture can be attached as one of the logical buffers of a framebuffer object with the commands" with "Multiple layers of a two-dimensional array texture or a two-dimensional multisample array texture can be attached as one of the logical buffers of a framebuffer object with the commands" Later in that section under "Errors" replace "An INVALID_VALUE error is generated if: - is a two-dimensional array texture and + is larger than the value of MAX_ARRAY_TEXTURE_LAYERS." with "An INVALID_VALUE error is generated if: - is a two-dimensional array texture or a two-dimensional multisample array texture and + is larger than the value of MAX_ARRAY_TEXTURE_LAYERS." Also replace "An INVALID_OPERATION error is generated if texture is non-zero and is not the name of a two-dimensional array texture." with "An INVALID_OPERATION error is generated if texture is non-zero and is not the name of a two-dimensional array texture or a two-dimensional multisample array texture." Issues (1) This extension is based on an OVR extension, why call it EXT? While started as a single vendor extension, OVR_multiview and OVR_multiview2 are already supported by multiple vendors. This new extension also has the support from multiple vendors to be specified as EXT. (2) Can this extension be used together with OVR_multiview_multisampled_render_to_texture if both are supported? The two extensions can be used together in the same application, but not in the same framebuffer. OVR_multiview_multisampled_render_to_texture is based on EXT_multisampled_render_to_texture, which explicitly does not permit a single framebuffer to contain explicit multisample texture types (from OpenGL ES 3.1 and core OpenGL) and "multisampled" bindings of non-multisample texture types. Revision History Rev. Date Author Changes ---- -------- -------- ----------------------------------------- 1 05/13/19 rmenzel Initial version.