Class ARBDrawIndirect


  • public class ARBDrawIndirect
    extends java.lang.Object
    Native bindings to the ARB_draw_indirect extension.

    This extension provides a mechanism for supplying the arguments to a DrawArraysInstanced or DrawElementsInstancedBaseVertex from buffer object memory. This is not particularly useful for applications where the CPU knows the values of the arguments beforehand, but is helpful when the values will be generated on the GPU through any mechanism that can write to a buffer object including image stores, atomic counters, or compute interop. This allows the GPU to consume these arguments without a round- trip to the CPU or the expensive synchronization that would involve. This is similar to the DrawTransformFeedbackEXT command from EXT_transform_feedback2, but offers much more flexibility in both generating the arguments and in the type of Draws that can be accomplished.

    Requires OpenGL 3.1. Promoted to core in OpenGL 4.0.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int GL_DRAW_INDIRECT_BUFFER
      Accepted by the target parameters of BindBuffer, BufferData, BufferSubData, MapBuffer, UnmapBuffer, GetBufferSubData, GetBufferPointerv, MapBufferRange, FlushMappedBufferRange, GetBufferParameteriv, and CopyBufferSubData.
      static int GL_DRAW_INDIRECT_BUFFER_BINDING
      Accepted by the value parameter of GetIntegerv, GetBooleanv, GetFloatv, and GetDoublev.
    • Field Detail

      • GL_DRAW_INDIRECT_BUFFER

        Accepted by the target parameters of BindBuffer, BufferData, BufferSubData, MapBuffer, UnmapBuffer, GetBufferSubData, GetBufferPointerv, MapBufferRange, FlushMappedBufferRange, GetBufferParameteriv, and CopyBufferSubData.
    • Method Detail

      • nglDrawArraysIndirect

        public static void nglDrawArraysIndirect​(int mode,
                                                 long indirect)
        Unsafe version of: DrawArraysIndirect
      • glDrawArraysIndirect

        public static void glDrawArraysIndirect​(int mode,
                                                java.nio.ByteBuffer indirect)
        
        public static void glDrawArraysIndirect​(int mode,
                                                long indirect)
        
        public static void glDrawArraysIndirect​(int mode,
                                                java.nio.IntBuffer indirect)
        
        Renders primitives from array data, taking parameters from memory.

        glDrawArraysIndirect behaves similarly to DrawArraysInstancedBaseInstance, except that the parameters to glDrawArraysInstancedBaseInstance are stored in memory at the address given by indirect.

        The parameters addressed by indirect are packed into a structure that takes the form (in C):

        
         typedef struct {
             uint count;
             uint primCount;
             uint first;
             uint baseInstance; // must be 0 unless OpenGL 4.2 is supported
         } DrawArraysIndirectCommand;
         
         const DrawArraysIndirectCommand *cmd = (const DrawArraysIndirectCommand *)indirect;
         glDrawArraysInstancedBaseInstance(mode, cmd->first, cmd->count, cmd->primCount, cmd->baseInstance);
        Parameters:
        mode - what kind of primitives to render. One of:
        POINTSLINE_STRIPLINE_LOOPLINESTRIANGLE_STRIPTRIANGLE_FANTRIANGLES
        LINES_ADJACENCYLINE_STRIP_ADJACENCYTRIANGLES_ADJACENCYTRIANGLE_STRIP_ADJACENCYPATCHESPOLYGONQUADS
        QUAD_STRIP
        indirect - a structure containing the draw parameters
      • nglDrawElementsIndirect

        public static void nglDrawElementsIndirect​(int mode,
                                                   int type,
                                                   long indirect)
        Unsafe version of: DrawElementsIndirect
      • glDrawElementsIndirect

        public static void glDrawElementsIndirect​(int mode,
                                                  int type,
                                                  java.nio.ByteBuffer indirect)
        
        public static void glDrawElementsIndirect​(int mode,
                                                  int type,
                                                  long indirect)
        
        public static void glDrawElementsIndirect​(int mode,
                                                  int type,
                                                  java.nio.IntBuffer indirect)
        
        Renders indexed primitives from array data, taking parameters from memory.

        glDrawElementsIndirect behaves similarly to DrawElementsInstancedBaseVertexBaseInstance, execpt that the parameters to glDrawElementsInstancedBaseVertexBaseInstance are stored in memory at the address given by indirect.

        The parameters addressed by indirect are packed into a structure that takes the form (in C):

        
         typedef struct {
             uint count;
             uint primCount;
             uint firstIndex;
             uint baseVertex;
             uint baseInstance;
         } DrawElementsIndirectCommand;

        glDrawElementsIndirect is equivalent to:

        
         void glDrawElementsIndirect(GLenum mode, GLenum type, const void *indirect) {
             const DrawElementsIndirectCommand *cmd  = (const DrawElementsIndirectCommand *)indirect;
             glDrawElementsInstancedBaseVertexBaseInstance(
                 mode,
                 cmd->count,
                 type,
                 cmd->firstIndex + size-of-type,
                 cmd->primCount,
                 cmd->baseVertex,
                 cmd->baseInstance
             );
         }
        Parameters:
        mode - what kind of primitives to render. One of:
        POINTSLINE_STRIPLINE_LOOPLINESTRIANGLE_STRIPTRIANGLE_FANTRIANGLES
        LINES_ADJACENCYLINE_STRIP_ADJACENCYTRIANGLES_ADJACENCYTRIANGLE_STRIP_ADJACENCYPATCHESPOLYGONQUADS
        QUAD_STRIP
        type - the type of data in the buffer bound to the ELEMENT_ARRAY_BUFFER binding. One of:
        UNSIGNED_BYTEUNSIGNED_SHORTUNSIGNED_INT
        indirect - the address of a structure containing the draw parameters
      • glDrawArraysIndirect

        public static void glDrawArraysIndirect​(int mode,
                                                int[] indirect)
        Array version of: DrawArraysIndirect
      • glDrawElementsIndirect

        public static void glDrawElementsIndirect​(int mode,
                                                  int type,
                                                  int[] indirect)
        Array version of: DrawElementsIndirect