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 "pipe/p_inlines.h"
  32 #include "pipe/p_winsys.h"
  33 #include "util/u_draw_quad.h"
  34
  35
  36 /**
  37  * Draw screen-aligned textured quad.
  38  */
  39 void
  40 util_draw_texquad(struct pipe_context *pipe,
  41                   float x0, float y0, float x1, float y1, float z)
  42 {
  43    struct pipe_buffer *vbuf;
  44    struct pipe_vertex_buffer vbuffer;
  45    struct pipe_vertex_element velement;
  46    uint numAttribs = 2, vertexBytes, i, j;
  47    float *v;
  48
  49    vertexBytes = 4 * (4 * numAttribs * sizeof(float));
  50
  51    /* XXX create one-time */
  52    vbuf = pipe->winsys->buffer_create(pipe->winsys, 32,
  53                                       PIPE_BUFFER_USAGE_VERTEX, vertexBytes);
  54    assert(vbuf);
  55
  56    v = (float *) pipe->winsys->buffer_map(pipe->winsys, vbuf,
  57                                           PIPE_BUFFER_USAGE_CPU_WRITE);
  58
  59    /*
  60     * Load vertex buffer
  61     */
  62    for (i = j = 0; i < 4; i++) {
  63       v[j + 2] = z;   /* z */
  64       v[j + 3] = 1.0; /* w */
  65       v[j + 6] = 0.0; /* r */
  66       v[j + 7] = 1.0; /* q */
  67       j += 8;
  68    }
  69
  70    v[0] = x0;
  71    v[1] = y0;
  72    v[4] = 0.0; /*s*/
  73    v[5] = 0.0; /*t*/
  74
  75    v[8] = x1;
  76    v[9] = y0;
  77    v[12] = 1.0;
  78    v[13] = 0.0;
  79
  80    v[16] = x1;
  81    v[17] = y1;
  82    v[20] = 1.0;
  83    v[21] = 1.0;
  84
  85    v[24] = x0;
  86    v[25] = y1;
  87    v[28] = 0.0;
  88    v[29] = 1.0;
  89
  90    pipe->winsys->buffer_unmap(pipe->winsys, vbuf);
  91
  92    /* tell pipe about the vertex buffer */
  93    vbuffer.buffer = vbuf;
  94    vbuffer.pitch = numAttribs * 4 * sizeof(float);  /* vertex size */
  95    vbuffer.buffer_offset = 0;
  96    pipe->set_vertex_buffer(pipe, 0, &vbuffer);
  97
  98    /* tell pipe about the vertex attributes */
  99    for (i = 0; i < numAttribs; i++) {
 100       velement.src_offset = i * 4 * sizeof(float);
 101       velement.vertex_buffer_index = 0;
 102       velement.src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
 103       velement.nr_components = 4;
 104       pipe->set_vertex_element(pipe, i, &velement);
 105    }
 106
 107    /* draw */
 108    pipe->draw_arrays(pipe, PIPE_PRIM_TRIANGLE_FAN, 0, 4);
 109
 110    /* XXX: do one-time */
 111    pipe_buffer_reference(pipe->winsys, &vbuf, NULL);
 112 }