GLDRAWTRANSFORMFEEDB(3G)

📦
version 1.1 · 7 versions
, in centos-stream 9

💅 NAME 💅

okay so this is the tea on glDrawTransformFeedbackStreamInstanced, straight from the GLDRAWTRANSFORMFEEDB(3G) manual page. Bestie, it renders multiple instances of primitives using a count derived from a specified stream of a transform feedback object. slay. ✨

🌸 C SPECIFICATION 🌸

void glDrawTransformFeedbackStreamInstanced(GLenum mode, GLuint id,
                                            GLuint stream,
                                            GLsizei primcount);

🎀 PARAMETERS 🎀

  • mode — tells the function what kind of primitives to render. The accepted symbolic constants are GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES, GL_LINE_STRIP_ADJACENCY, GL_LINES_ADJACENCY, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES, GL_TRIANGLE_STRIP_ADJACENCY, GL_TRIANGLES_ADJACENCY, and GL_PATCHES. that’s the whole accepted list, no cap. 💅
  • id — the name of a transform feedback object, and it’s the object you pull a primitive count from. 🫶
  • stream — the index of the transform feedback stream you pull the primitive count from. ✨
  • primcount — how many instances of the geometry to render. literally the instance count, bestie. 🌸

🦋 DESCRIPTION 🦋

glDrawTransformFeedbackStreamInstanced draws multiple copies of a range of primitives of a type specified by mode, using a count retrieved from the transform feedback stream specified by stream of the transform feedback object specified by id. it’s giving “draw the thing, but the count comes from transform feedback energy.” 💖

Calling glDrawTransformFeedbackStreamInstanced is equivalent to calling glDrawArraysInstanced() with mode and primcount as specified, first set to zero, and count set to the number of vertices captured on vertex stream stream the last time transform feedback was active on the transform feedback object named by id.

Calling glDrawTransformFeedbackInstanced() is equivalent to calling glDrawTransformFeedbackStreamInstanced with stream set to zero. yes ma’am, that’s the shortcut vibe. 👑

💀 ERRORS 💀

  • GL_INVALID_ENUM is generated if mode is not an accepted value. 🚩
  • GL_INVALID_VALUE is generated if id is not the name of a transform feedback object.
  • GL_INVALID_VALUE is generated if stream is greater than or equal to the value of GL_MAX_VERTEX_STREAMS.
  • GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to an enabled array and the buffer object’s data store is currently mapped.
  • GL_INVALID_OPERATION is generated if a geometry shader is active and mode is incompatible with the input primitive type of the geometry shader in the currently installed program object.
  • GL_INVALID_OPERATION is generated if mode is GL_PATCHES and no tessellation control shader is active.
  • GL_INVALID_OPERATION is generated if glEndTransformFeedback has never been called while the transform feedback object named by id was bound.
bestie, those last few GL_INVALID_OPERATION hits are not a vibe. check your buffers, shaders, and transform feedback state before you send it. 😭

👑 VERSION SUPPORT 👑

here’s the version vibe check, matching the table’s values exactly. the function / feature name is glDrawTransformFeedbackStreamInstanced. ✨

  • OpenGL 2.0: -
  • OpenGL 2.1: -
  • OpenGL 3.0: -
  • OpenGL 3.1: -
  • OpenGL 3.2: -
  • OpenGL 3.3: -
  • OpenGL 4.0: -
  • OpenGL 4.1: -
  • OpenGL 4.2: ✔
  • OpenGL 4.3: ✔
  • OpenGL 4.4: ✔
  • OpenGL 4.5: ✔

so the checkmarks only show up from 4.2 onward in this table. iconic. ⭐

🌈 SEE ALSO 🌈

  • glDrawArrays()
  • glDrawArraysInstanced()
  • glDrawElements()
  • glDrawRangeElements()
  • glDrawTransformFeedback()
  • glDrawTransformFeedbackStream()

Copyright © 2010-2014 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.

Copyright © 2010-2014 Khronos Group.

mwah 💋 okay bestie, that’s the whole page: source/version [FIXME: source], date 08/09/2021, manual GLDRAWTRANSFORMFEEDB(3G). byeee, go draw something cute. 🫶🎀

📦 where this page comes from