src/gallium/auxiliary/util/u_draw_quad.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 #include "pipe/p_context.h"
  30 #include "pipe/p_defines.h"
  31 #include "util/u_inlines.h"
  32 #include "util/u_draw_quad.h"
  33 #include "util/u_memory.h"
  34
  35
  36 /**
  37  * Draw a simple vertex buffer / primitive.
  38  * Limited to float[4] vertex attribs, tightly packed.
  39  */
  40 void
  41 util_draw_vertex_buffer(struct pipe_context *pipe,
  42                         struct pipe_resource *vbuf,
  43                         uint offset,
  44                         uint prim_type,
  45                         uint num_verts,
  46                         uint num_attribs)
  47 {
  48    struct pipe_vertex_buffer vbuffer;
  49
  50    assert(num_attribs <= PIPE_MAX_ATTRIBS);
  51
  52    /* tell pipe about the vertex buffer */
  53    memset(&vbuffer, 0, sizeof(vbuffer));
  54    vbuffer.buffer = vbuf;
  55    vbuffer.stride = num_attribs * 4 * sizeof(float);  /* vertex size */
  56    vbuffer.buffer_offset = offset;
  57    vbuffer.max_index = num_verts - 1;
  58    pipe->set_vertex_buffers(pipe, 1, &vbuffer);
  59
  60    /* note: vertex elements already set by caller */
  61
  62    /* draw */
  63    pipe->draw_arrays(pipe, prim_type, 0, num_verts);
  64 }
  65
  66
  67
  68 /**
  69  * Draw screen-aligned textured quad.
  70  * Note: this isn't especially efficient.
  71  */
  72 void
  73 util_draw_texquad(struct pipe_context *pipe,
  74                   float x0, float y0, float x1, float y1, float z)
  75 {
  76    uint numAttribs = 2, i, j;
  77    uint vertexBytes = 4 * (4 * numAttribs * sizeof(float));
  78    struct pipe_resource *vbuf = NULL;
  79    uint *v = NULL;
  80
  81    v = MALLOC(vertexBytes);
  82    if (v == NULL)
  83       goto out;
  84
  85    /*
  86     * Load vertex buffer
  87     */
  88    for (i = j = 0; i < 4; i++) {
  89       v[j + 2] = z;   /* z */
  90       v[j + 3] = 1.0; /* w */
  91       v[j + 6] = 0.0; /* r */
  92       v[j + 7] = 1.0; /* q */
  93       j += 8;
  94    }
  95
  96    v[0] = x0;
  97    v[1] = y0;
  98    v[4] = 0.0; /*s*/
  99    v[5] = 0.0; /*t*/
 100
 101    v[8] = x1;
 102    v[9] = y0;
 103    v[12] = 1.0;
 104    v[13] = 0.0;
 105
 106    v[16] = x1;
 107    v[17] = y1;
 108    v[20] = 1.0;
 109    v[21] = 1.0;
 110
 111    v[24] = x0;
 112    v[25] = y1;
 113    v[28] = 0.0;
 114    v[29] = 1.0;
 115
 116    vbuf = pipe_user_buffer_create(pipe->screen, v, vertexBytes,
 117                                   PIPE_BIND_VERTEX_BUFFER);
 118    if (!vbuf)
 119       goto out;
 120
 121    util_draw_vertex_buffer(pipe, vbuf, 0, PIPE_PRIM_TRIANGLE_FAN, 4, 2);
 122
 123 out:
 124    if (vbuf)
 125       pipe_resource_reference(&vbuf, NULL);
 126
 127    if (v)
 128       FREE(v);
 129 }