src/mesa/state_tracker/st_draw.c - third_party/mesa - Git at Google

 /**************************************************************************
  *
  * Copyright 2007 VMware, Inc.
  * All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
  * without limitation the rights to use, copy, modify, merge, publish,
  * distribute, sub license, and/or sell copies of the Software, and to
  * permit persons to whom the Software is furnished to do so, subject to
  * the following conditions:
  *
  * The above copyright notice and this permission notice (including the
  * next paragraph) shall be included in all copies or substantial portions
  * of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
  **************************************************************************/

 /*
  * This file implements the st_draw_vbo() function which is called from
  * Mesa's VBO module.  All point/line/triangle rendering is done through
  * this function whether the user called glBegin/End, glDrawArrays,
  * glDrawElements, glEvalMesh, or glCalList, etc.
  *
  * Authors:
  *   Keith Whitwell <keithw@vmware.com>
  */

 #include "main/context.h"
 #include "main/errors.h"

 #include "main/image.h"
 #include "main/bufferobj.h"
 #include "main/macros.h"
 #include "main/varray.h"

 #include "compiler/glsl/ir_uniform.h"

 #include "vbo/vbo.h"

 #include "st_context.h"
 #include "st_atom.h"
 #include "st_cb_bitmap.h"
 #include "st_debug.h"
 #include "st_draw.h"
 #include "st_program.h"
 #include "st_util.h"

 #include "pipe/p_context.h"
 #include "pipe/p_defines.h"
 #include "util/u_cpu_detect.h"
 #include "util/u_inlines.h"
 #include "util/format/u_format.h"
 #include "util/u_prim.h"
 #include "util/u_draw.h"
 #include "util/u_upload_mgr.h"
 #include "util/u_threaded_context.h"
 #include "draw/draw_context.h"
 #include "cso_cache/cso_context.h"

 /* GL prims should match Gallium prims, spot-check a few */
 static_assert(GL_POINTS == MESA_PRIM_POINTS, "enum mismatch");
 static_assert(GL_QUADS == MESA_PRIM_QUADS, "enum mismatch");
 static_assert(GL_TRIANGLE_STRIP_ADJACENCY == MESA_PRIM_TRIANGLE_STRIP_ADJACENCY, "enum mismatch");
 static_assert(GL_PATCHES == MESA_PRIM_PATCHES, "enum mismatch");

 void
 st_prepare_draw(struct gl_context *ctx, uint64_t state_mask)
 {
    struct st_context *st = ctx->st;

    /* Mesa core state should have been validated already */
    assert(ctx->NewState == 0x0);

    if (unlikely(!st->bitmap.cache.empty))
       st_flush_bitmap_cache(st);

    st_invalidate_readpix_cache(st);

    /* Validate state. */
    st_validate_state(st, state_mask);

    /* Apply our thread scheduling policy for better multithreading
     * performance.
     */
    if (unlikely(st->pin_thread_counter != ST_THREAD_SCHEDULER_DISABLED &&
                 /* do it occasionally */
                 ++st->pin_thread_counter % 512 == 0)) {
       st->pin_thread_counter = 0;

       int cpu = util_get_current_cpu();
       if (cpu >= 0) {
          struct pipe_context *pipe = st->pipe;
          uint16_t L3_cache = util_get_cpu_caps()->cpu_to_L3[cpu];

          if (L3_cache != U_CPU_INVALID_L3) {
             pipe->set_context_param(pipe,
                                     PIPE_CONTEXT_PARAM_UPDATE_THREAD_SCHEDULING,
                                     cpu);
          }
       }
    }
 }

 void
 st_draw_gallium(struct gl_context *ctx,
                 const struct pipe_draw_info *info,
                 unsigned drawid_offset,
                 const struct pipe_draw_indirect_info *indirect,
                 const struct pipe_draw_start_count_bias *draws,
                 unsigned num_draws)
 {
    struct st_context *st = st_context(ctx);

    cso_draw_vbo(st->cso_context, info, drawid_offset, indirect, draws, num_draws);
 }

 static void
 st_draw_gallium_multimode(struct gl_context *ctx,
                           struct pipe_draw_info *info,
                           const struct pipe_draw_start_count_bias *draws,
                           const unsigned char *mode,
                           unsigned num_draws)
 {
    struct st_context *st = st_context(ctx);

    unsigned i, first;
    struct cso_context *cso = st->cso_context;

    /* Find consecutive draws where mode doesn't vary. */
    for (i = 0, first = 0; i <= num_draws; i++) {
       if (i == num_draws || mode[i] != mode[first]) {
          info->mode = mode[first];
          cso_draw_vbo(cso, info, 0, NULL, &draws[first], i - first);
          first = i;

          /* We can pass the reference only once. st_buffer_object keeps
           * the reference alive for later draws.
           */
          info->take_index_buffer_ownership = false;
       }
    }
 }

 static void
 rewrite_partial_stride_indirect(struct st_context *st,
                             const struct pipe_draw_info *info,
                             const struct pipe_draw_indirect_info *indirect,
                             const struct pipe_draw_start_count_bias draw)
 {
    unsigned draw_count = 0;
    struct u_indirect_params *new_draws = util_draw_indirect_read(st->pipe, info, indirect, &draw_count);
    if (!new_draws)
       return;
    for (unsigned i = 0; i < draw_count; i++)
       st->ctx->Driver.DrawGallium(st->ctx, &new_draws[i].info, i, NULL, &new_draws[i].draw, 1);
    free(new_draws);
 }

 void
 st_indirect_draw_vbo(struct gl_context *ctx,
                      GLenum mode, GLenum index_type,
                      GLintptr indirect_offset,
                      GLintptr indirect_draw_count_offset,
                      GLsizei draw_count, GLsizei stride)
 {
    struct gl_buffer_object *indirect_data = ctx->DrawIndirectBuffer;
    struct gl_buffer_object *indirect_draw_count = ctx->ParameterBuffer;
    struct st_context *st = st_context(ctx);
    struct pipe_draw_info info;
    struct pipe_draw_indirect_info indirect;
    struct pipe_draw_start_count_bias draw = {0};

    /* If indirect_draw_count is set, drawcount is the maximum draw count.*/
    if (!draw_count)
       return;

    assert(stride);
    st_prepare_draw(ctx, ST_PIPELINE_RENDER_STATE_MASK);

    memset(&indirect, 0, sizeof(indirect));
    util_draw_init_info(&info);
    info.max_index = ~0u; /* so that u_vbuf can tell that it's unknown */

    switch (index_type) {
    case GL_UNSIGNED_BYTE:
       info.index_size = 1;
       break;
    case GL_UNSIGNED_SHORT:
       info.index_size = 2;
       break;
    case GL_UNSIGNED_INT:
       info.index_size = 4;
       break;
    }

    assert(st->has_multi_draw_indirect || !indirect_draw_count);

    if (info.index_size) {
       struct gl_buffer_object *bufobj = ctx->Array.VAO->IndexBufferObj;

       /* indices are always in a real VBO */
       assert(bufobj);

       if (st->pipe->draw_vbo == tc_draw_vbo &&
           (draw_count == 1 || st->has_multi_draw_indirect)) {
          /* Fast path for u_threaded_context to eliminate atomics. */
          info.index.resource = _mesa_get_bufferobj_reference(ctx, bufobj);
          info.take_index_buffer_ownership = true;
       } else {
          info.index.resource = bufobj->buffer;
       }

       /* No index buffer storage allocated - nothing to do. */
       if (!info.index.resource)
          return;

       draw.start = 0;

       unsigned index_size_shift = util_logbase2(info.index_size);
       info.restart_index = ctx->Array._RestartIndex[index_size_shift];
       info.primitive_restart = ctx->Array._PrimitiveRestart[index_size_shift];
    }

    info.mode = mode;
    indirect.buffer = indirect_data->buffer;
    indirect.offset = indirect_offset;

    /* Viewperf2020/Maya draws with a buffer that has no storage. */
    if (!indirect.buffer)
       return;

    if (!st->has_multi_draw_indirect) {
       int i;

       indirect.draw_count = 1;
       for (i = 0; i < draw_count; i++) {
          ctx->Driver.DrawGallium(ctx, &info, i, &indirect, &draw, 1);
          indirect.offset += stride;
       }
    } else {
       indirect.draw_count = draw_count;
       indirect.stride = stride;
       if (!st->has_indirect_partial_stride && stride &&
           (draw_count > 1 || indirect_draw_count)) {
          /* DrawElementsIndirectCommand or DrawArraysIndirectCommand */
          const size_t struct_size = info.index_size ? sizeof(uint32_t) * 5 : sizeof(uint32_t) * 4;
          if (indirect.stride && indirect.stride < struct_size) {
             rewrite_partial_stride_indirect(st, &info, &indirect, draw);
             return;
          }
       }
       if (indirect_draw_count) {
          indirect.indirect_draw_count =
             indirect_draw_count->buffer;
          indirect.indirect_draw_count_offset = indirect_draw_count_offset;
       }
       ctx->Driver.DrawGallium(ctx, &info, 0, &indirect, &draw, 1);
    }

    if (MESA_DEBUG_FLAGS & DEBUG_ALWAYS_FLUSH)
       _mesa_flush(ctx);
 }


 void
 st_init_draw_functions(struct pipe_screen *screen,
                        struct dd_function_table *functions)
 {
    functions->DrawGallium = st_draw_gallium;
    functions->DrawGalliumMultiMode = st_draw_gallium_multimode;
 }


 void
 st_destroy_draw(struct st_context *st)
 {
    draw_destroy(st->draw);
 }

 /**
  * Getter for the draw_context, so that initialization of it can happen only
  * when needed (the TGSI exec machines take up quite a bit of memory).
  */
 struct draw_context *
 st_get_draw_context(struct st_context *st)
 {
    if (!st->draw) {
       st->draw = draw_create(st->pipe);
       if (!st->draw) {
          _mesa_error(st->ctx, GL_OUT_OF_MEMORY, "feedback fallback allocation");
          return NULL;
       }
    }

    /* Disable draw options that might convert points/lines to tris, etc.
     * as that would foul-up feedback/selection mode.
     */
    draw_wide_line_threshold(st->draw, 1000.0f);
    draw_wide_point_threshold(st->draw, 1000.0f);
    draw_enable_line_stipple(st->draw, false);
    draw_enable_point_sprites(st->draw, false);

    return st->draw;
 }

 /**
  * Draw a quad with given position, texcoords and color.
  */
 bool
 st_draw_quad(struct st_context *st,
              float x0, float y0, float x1, float y1, float z,
              float s0, float t0, float s1, float t1,
              const float *color,
              unsigned num_instances)
 {
    struct pipe_vertex_buffer vb = {0};
    struct st_util_vertex *verts;

    u_upload_alloc(st->pipe->stream_uploader, 0,
                   4 * sizeof(struct st_util_vertex), 4,
                   &vb.buffer_offset, &vb.buffer.resource, (void **) &verts);
    if (!vb.buffer.resource) {
       return false;
    }

    /* lower-left */
    verts[0].x = x0;
    verts[0].y = y1;
    verts[0].z = z;
    verts[0].r = color[0];
    verts[0].g = color[1];
    verts[0].b = color[2];
    verts[0].a = color[3];
    verts[0].s = s0;
    verts[0].t = t0;

    /* lower-right */
    verts[1].x = x1;
    verts[1].y = y1;
    verts[1].z = z;
    verts[1].r = color[0];
    verts[1].g = color[1];
    verts[1].b = color[2];
    verts[1].a = color[3];
    verts[1].s = s1;
    verts[1].t = t0;

    /* upper-right */
    verts[2].x = x1;
    verts[2].y = y0;
    verts[2].z = z;
    verts[2].r = color[0];
    verts[2].g = color[1];
    verts[2].b = color[2];
    verts[2].a = color[3];
    verts[2].s = s1;
    verts[2].t = t1;

    /* upper-left */
    verts[3].x = x0;
    verts[3].y = y0;
    verts[3].z = z;
    verts[3].r = color[0];
    verts[3].g = color[1];
    verts[3].b = color[2];
    verts[3].a = color[3];
    verts[3].s = s0;
    verts[3].t = t1;

    u_upload_unmap(st->pipe->stream_uploader);

    cso_set_vertex_buffers(st->cso_context, 1, true, &vb);

    if (num_instances > 1) {
       cso_draw_arrays_instanced(st->cso_context, MESA_PRIM_TRIANGLE_FAN, 0, 4,
                                 0, num_instances);
    } else {
       cso_draw_arrays(st->cso_context, MESA_PRIM_TRIANGLE_FAN, 0, 4);
    }

    return true;
 }

 static void
 st_hw_select_draw_gallium(struct gl_context *ctx,
                           const struct pipe_draw_info *info,
                           unsigned drawid_offset,
                           const struct pipe_draw_indirect_info *indirect,
                           const struct pipe_draw_start_count_bias *draws,
                           unsigned num_draws)
 {
    struct st_context *st = st_context(ctx);
    enum mesa_prim old_mode = info->mode;

    if (st_draw_hw_select_prepare_common(ctx) &&
        /* Removing "const" is fine because we restore the changed mode
         * at the end. */
        st_draw_hw_select_prepare_mode(ctx, ((struct pipe_draw_info*)info))) {
       cso_draw_vbo(st->cso_context, info, drawid_offset, indirect, draws,
                    num_draws);
    }

    ((struct pipe_draw_info*)info)->mode = old_mode;
 }

 static void
 st_hw_select_draw_gallium_multimode(struct gl_context *ctx,
                                     struct pipe_draw_info *info,
                                     const struct pipe_draw_start_count_bias *draws,
                                     const unsigned char *mode,
                                     unsigned num_draws)
 {
    struct st_context *st = st_context(ctx);

    if (!st_draw_hw_select_prepare_common(ctx))
       return;

    unsigned i, first;
    struct cso_context *cso = st->cso_context;

    /* Find consecutive draws where mode doesn't vary. */
    for (i = 0, first = 0; i <= num_draws; i++) {
       if (i == num_draws || mode[i] != mode[first]) {
          info->mode = mode[first];

          if (st_draw_hw_select_prepare_mode(ctx, info))
             cso_draw_vbo(cso, info, 0, NULL, &draws[first], i - first);

          first = i;

          /* We can pass the reference only once. st_buffer_object keeps
           * the reference alive for later draws.
           */
          info->take_index_buffer_ownership = false;
       }
    }
 }

 void
 st_init_hw_select_draw_functions(struct pipe_screen *screen,
                                  struct dd_function_table *functions)
 {
    functions->DrawGallium = st_hw_select_draw_gallium;
    functions->DrawGalliumMultiMode = st_hw_select_draw_gallium_multimode;
 }
	/**************************************************************************
	*
	* Copyright 2007 VMware, Inc.
	* All Rights Reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the
	* "Software"), to deal in the Software without restriction, including
	* without limitation the rights to use, copy, modify, merge, publish,
	* distribute, sub license, and/or sell copies of the Software, and to
	* permit persons to whom the Software is furnished to do so, subject to
	* the following conditions:
	*
	* The above copyright notice and this permission notice (including the
	* next paragraph) shall be included in all copies or substantial portions
	* of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
	* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
	* IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
	* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
	* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
	* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*
	**************************************************************************/

	/*
	* This file implements the st_draw_vbo() function which is called from
	* Mesa's VBO module. All point/line/triangle rendering is done through
	* this function whether the user called glBegin/End, glDrawArrays,
	* glDrawElements, glEvalMesh, or glCalList, etc.
	*
	* Authors:
	* Keith Whitwell <keithw@vmware.com>
	*/

	#include "main/context.h"
	#include "main/errors.h"

	#include "main/image.h"
	#include "main/bufferobj.h"
	#include "main/macros.h"
	#include "main/varray.h"

	#include "compiler/glsl/ir_uniform.h"

	#include "vbo/vbo.h"

	#include "st_context.h"
	#include "st_atom.h"
	#include "st_cb_bitmap.h"
	#include "st_debug.h"
	#include "st_draw.h"
	#include "st_program.h"
	#include "st_util.h"

	#include "pipe/p_context.h"
	#include "pipe/p_defines.h"
	#include "util/u_cpu_detect.h"
	#include "util/u_inlines.h"
	#include "util/format/u_format.h"
	#include "util/u_prim.h"
	#include "util/u_draw.h"
	#include "util/u_upload_mgr.h"
	#include "util/u_threaded_context.h"
	#include "draw/draw_context.h"
	#include "cso_cache/cso_context.h"

	/* GL prims should match Gallium prims, spot-check a few */
	static_assert(GL_POINTS == MESA_PRIM_POINTS, "enum mismatch");
	static_assert(GL_QUADS == MESA_PRIM_QUADS, "enum mismatch");
	static_assert(GL_TRIANGLE_STRIP_ADJACENCY == MESA_PRIM_TRIANGLE_STRIP_ADJACENCY, "enum mismatch");
	static_assert(GL_PATCHES == MESA_PRIM_PATCHES, "enum mismatch");

	void
	st_prepare_draw(struct gl_context *ctx, uint64_t state_mask)
	{
	struct st_context *st = ctx->st;

	/* Mesa core state should have been validated already */
	assert(ctx->NewState == 0x0);

	if (unlikely(!st->bitmap.cache.empty))
	st_flush_bitmap_cache(st);

	st_invalidate_readpix_cache(st);

	/* Validate state. */
	st_validate_state(st, state_mask);

	/* Apply our thread scheduling policy for better multithreading
	* performance.
	*/
	if (unlikely(st->pin_thread_counter != ST_THREAD_SCHEDULER_DISABLED &&
	/* do it occasionally */
	++st->pin_thread_counter % 512 == 0)) {
	st->pin_thread_counter = 0;

	int cpu = util_get_current_cpu();
	if (cpu >= 0) {
	struct pipe_context *pipe = st->pipe;
	uint16_t L3_cache = util_get_cpu_caps()->cpu_to_L3[cpu];

	if (L3_cache != U_CPU_INVALID_L3) {
	pipe->set_context_param(pipe,
	PIPE_CONTEXT_PARAM_UPDATE_THREAD_SCHEDULING,
	cpu);
	}
	}
	}
	}

	void
	st_draw_gallium(struct gl_context *ctx,
	const struct pipe_draw_info *info,
	unsigned drawid_offset,
	const struct pipe_draw_indirect_info *indirect,
	const struct pipe_draw_start_count_bias *draws,
	unsigned num_draws)
	{
	struct st_context *st = st_context(ctx);

	cso_draw_vbo(st->cso_context, info, drawid_offset, indirect, draws, num_draws);
	}

	static void
	st_draw_gallium_multimode(struct gl_context *ctx,
	struct pipe_draw_info *info,
	const struct pipe_draw_start_count_bias *draws,
	const unsigned char *mode,
	unsigned num_draws)
	{
	struct st_context *st = st_context(ctx);

	unsigned i, first;
	struct cso_context *cso = st->cso_context;

	/* Find consecutive draws where mode doesn't vary. */
	for (i = 0, first = 0; i <= num_draws; i++) {
	if (i == num_draws \|\| mode[i] != mode[first]) {
	info->mode = mode[first];
	cso_draw_vbo(cso, info, 0, NULL, &draws[first], i - first);
	first = i;

	/* We can pass the reference only once. st_buffer_object keeps
	* the reference alive for later draws.
	*/
	info->take_index_buffer_ownership = false;
	}
	}
	}

	static void
	rewrite_partial_stride_indirect(struct st_context *st,
	const struct pipe_draw_info *info,
	const struct pipe_draw_indirect_info *indirect,
	const struct pipe_draw_start_count_bias draw)
	{
	unsigned draw_count = 0;
	struct u_indirect_params *new_draws = util_draw_indirect_read(st->pipe, info, indirect, &draw_count);
	if (!new_draws)
	return;
	for (unsigned i = 0; i < draw_count; i++)
	st->ctx->Driver.DrawGallium(st->ctx, &new_draws[i].info, i, NULL, &new_draws[i].draw, 1);
	free(new_draws);
	}

	void
	st_indirect_draw_vbo(struct gl_context *ctx,
	GLenum mode, GLenum index_type,
	GLintptr indirect_offset,
	GLintptr indirect_draw_count_offset,
	GLsizei draw_count, GLsizei stride)
	{
	struct gl_buffer_object *indirect_data = ctx->DrawIndirectBuffer;
	struct gl_buffer_object *indirect_draw_count = ctx->ParameterBuffer;
	struct st_context *st = st_context(ctx);
	struct pipe_draw_info info;
	struct pipe_draw_indirect_info indirect;
	struct pipe_draw_start_count_bias draw = {0};

	/* If indirect_draw_count is set, drawcount is the maximum draw count.*/
	if (!draw_count)
	return;

	assert(stride);
	st_prepare_draw(ctx, ST_PIPELINE_RENDER_STATE_MASK);

	memset(&indirect, 0, sizeof(indirect));
	util_draw_init_info(&info);
	info.max_index = ~0u; /* so that u_vbuf can tell that it's unknown */

	switch (index_type) {
	case GL_UNSIGNED_BYTE:
	info.index_size = 1;
	break;
	case GL_UNSIGNED_SHORT:
	info.index_size = 2;
	break;
	case GL_UNSIGNED_INT:
	info.index_size = 4;
	break;
	}

	assert(st->has_multi_draw_indirect \|\| !indirect_draw_count);

	if (info.index_size) {
	struct gl_buffer_object *bufobj = ctx->Array.VAO->IndexBufferObj;

	/* indices are always in a real VBO */
	assert(bufobj);

	if (st->pipe->draw_vbo == tc_draw_vbo &&
	(draw_count == 1 \|\| st->has_multi_draw_indirect)) {
	/* Fast path for u_threaded_context to eliminate atomics. */
	info.index.resource = _mesa_get_bufferobj_reference(ctx, bufobj);
	info.take_index_buffer_ownership = true;
	} else {
	info.index.resource = bufobj->buffer;
	}

	/* No index buffer storage allocated - nothing to do. */
	if (!info.index.resource)
	return;

	draw.start = 0;

	unsigned index_size_shift = util_logbase2(info.index_size);
	info.restart_index = ctx->Array._RestartIndex[index_size_shift];
	info.primitive_restart = ctx->Array._PrimitiveRestart[index_size_shift];
	}

	info.mode = mode;
	indirect.buffer = indirect_data->buffer;
	indirect.offset = indirect_offset;

	/* Viewperf2020/Maya draws with a buffer that has no storage. */
	if (!indirect.buffer)
	return;

	if (!st->has_multi_draw_indirect) {
	int i;

	indirect.draw_count = 1;
	for (i = 0; i < draw_count; i++) {
	ctx->Driver.DrawGallium(ctx, &info, i, &indirect, &draw, 1);
	indirect.offset += stride;
	}
	} else {
	indirect.draw_count = draw_count;
	indirect.stride = stride;
	if (!st->has_indirect_partial_stride && stride &&
	(draw_count > 1 \|\| indirect_draw_count)) {
	/* DrawElementsIndirectCommand or DrawArraysIndirectCommand */
	const size_t struct_size = info.index_size ? sizeof(uint32_t) * 5 : sizeof(uint32_t) * 4;
	if (indirect.stride && indirect.stride < struct_size) {
	rewrite_partial_stride_indirect(st, &info, &indirect, draw);
	return;
	}
	}
	if (indirect_draw_count) {
	indirect.indirect_draw_count =
	indirect_draw_count->buffer;
	indirect.indirect_draw_count_offset = indirect_draw_count_offset;
	}
	ctx->Driver.DrawGallium(ctx, &info, 0, &indirect, &draw, 1);
	}

	if (MESA_DEBUG_FLAGS & DEBUG_ALWAYS_FLUSH)
	_mesa_flush(ctx);
	}


	void
	st_init_draw_functions(struct pipe_screen *screen,
	struct dd_function_table *functions)
	{
	functions->DrawGallium = st_draw_gallium;
	functions->DrawGalliumMultiMode = st_draw_gallium_multimode;
	}


	void
	st_destroy_draw(struct st_context *st)
	{
	draw_destroy(st->draw);
	}

	/**
	* Getter for the draw_context, so that initialization of it can happen only
	* when needed (the TGSI exec machines take up quite a bit of memory).
	*/
	struct draw_context *
	st_get_draw_context(struct st_context *st)
	{
	if (!st->draw) {
	st->draw = draw_create(st->pipe);
	if (!st->draw) {
	_mesa_error(st->ctx, GL_OUT_OF_MEMORY, "feedback fallback allocation");
	return NULL;
	}
	}

	/* Disable draw options that might convert points/lines to tris, etc.
	* as that would foul-up feedback/selection mode.
	*/
	draw_wide_line_threshold(st->draw, 1000.0f);
	draw_wide_point_threshold(st->draw, 1000.0f);
	draw_enable_line_stipple(st->draw, false);
	draw_enable_point_sprites(st->draw, false);

	return st->draw;
	}

	/**
	* Draw a quad with given position, texcoords and color.
	*/
	bool
	st_draw_quad(struct st_context *st,
	float x0, float y0, float x1, float y1, float z,
	float s0, float t0, float s1, float t1,
	const float *color,
	unsigned num_instances)
	{
	struct pipe_vertex_buffer vb = {0};
	struct st_util_vertex *verts;

	u_upload_alloc(st->pipe->stream_uploader, 0,
	4 * sizeof(struct st_util_vertex), 4,
	&vb.buffer_offset, &vb.buffer.resource, (void **) &verts);
	if (!vb.buffer.resource) {
	return false;
	}

	/* lower-left */
	verts[0].x = x0;
	verts[0].y = y1;
	verts[0].z = z;
	verts[0].r = color[0];
	verts[0].g = color[1];
	verts[0].b = color[2];
	verts[0].a = color[3];
	verts[0].s = s0;
	verts[0].t = t0;

	/* lower-right */
	verts[1].x = x1;
	verts[1].y = y1;
	verts[1].z = z;
	verts[1].r = color[0];
	verts[1].g = color[1];
	verts[1].b = color[2];
	verts[1].a = color[3];
	verts[1].s = s1;
	verts[1].t = t0;

	/* upper-right */
	verts[2].x = x1;
	verts[2].y = y0;
	verts[2].z = z;
	verts[2].r = color[0];
	verts[2].g = color[1];
	verts[2].b = color[2];
	verts[2].a = color[3];
	verts[2].s = s1;
	verts[2].t = t1;

	/* upper-left */
	verts[3].x = x0;
	verts[3].y = y0;
	verts[3].z = z;
	verts[3].r = color[0];
	verts[3].g = color[1];
	verts[3].b = color[2];
	verts[3].a = color[3];
	verts[3].s = s0;
	verts[3].t = t1;

	u_upload_unmap(st->pipe->stream_uploader);

	cso_set_vertex_buffers(st->cso_context, 1, true, &vb);

	if (num_instances > 1) {
	cso_draw_arrays_instanced(st->cso_context, MESA_PRIM_TRIANGLE_FAN, 0, 4,
	0, num_instances);
	} else {
	cso_draw_arrays(st->cso_context, MESA_PRIM_TRIANGLE_FAN, 0, 4);
	}

	return true;
	}

	static void
	st_hw_select_draw_gallium(struct gl_context *ctx,
	const struct pipe_draw_info *info,
	unsigned drawid_offset,
	const struct pipe_draw_indirect_info *indirect,
	const struct pipe_draw_start_count_bias *draws,
	unsigned num_draws)
	{
	struct st_context *st = st_context(ctx);
	enum mesa_prim old_mode = info->mode;

	if (st_draw_hw_select_prepare_common(ctx) &&
	/* Removing "const" is fine because we restore the changed mode
	* at the end. */
	st_draw_hw_select_prepare_mode(ctx, ((struct pipe_draw_info*)info))) {
	cso_draw_vbo(st->cso_context, info, drawid_offset, indirect, draws,
	num_draws);
	}

	((struct pipe_draw_info*)info)->mode = old_mode;
	}

	static void
	st_hw_select_draw_gallium_multimode(struct gl_context *ctx,
	struct pipe_draw_info *info,
	const struct pipe_draw_start_count_bias *draws,
	const unsigned char *mode,
	unsigned num_draws)
	{
	struct st_context *st = st_context(ctx);

	if (!st_draw_hw_select_prepare_common(ctx))
	return;

	unsigned i, first;
	struct cso_context *cso = st->cso_context;

	/* Find consecutive draws where mode doesn't vary. */
	for (i = 0, first = 0; i <= num_draws; i++) {
	if (i == num_draws \|\| mode[i] != mode[first]) {
	info->mode = mode[first];

	if (st_draw_hw_select_prepare_mode(ctx, info))
	cso_draw_vbo(cso, info, 0, NULL, &draws[first], i - first);

	first = i;

	/* We can pass the reference only once. st_buffer_object keeps
	* the reference alive for later draws.
	*/
	info->take_index_buffer_ownership = false;
	}
	}
	}

	void
	st_init_hw_select_draw_functions(struct pipe_screen *screen,
	struct dd_function_table *functions)
	{
	functions->DrawGallium = st_hw_select_draw_gallium;
	functions->DrawGalliumMultiMode = st_hw_select_draw_gallium_multimode;
	}