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 "util/u_draw_quad.h"
  33
  34
  35 /**
  36  * Draw a simple vertex buffer / primitive.
  37  * Limited to float[4] vertex attribs, tightly packed.
  38  */
  39 void
  40 util_draw_vertex_buffer(struct pipe_context *pipe,
  41                         struct pipe_buffer *vbuf,
  42                         uint offset,
  43                         uint prim_type,
  44                         uint num_verts,
  45                         uint num_attribs)
  46 {
  47    struct pipe_vertex_buffer vbuffer;
  48    struct pipe_vertex_element velements[PIPE_MAX_ATTRIBS];
  49    uint i;
  50
  51    assert(num_attribs <= PIPE_MAX_ATTRIBS);
  52
  53    /* tell pipe about the vertex buffer */
  54    memset(&vbuffer, 0, sizeof(vbuffer));
  55    vbuffer.buffer = vbuf;
  56    vbuffer.stride = num_attribs * 4 * sizeof(float);  /* vertex size */
  57    vbuffer.buffer_offset = offset;
  58    vbuffer.max_index = num_verts - 1;
  59    pipe->set_vertex_buffers(pipe, 1, &vbuffer);
  60
  61    /* tell pipe about the vertex attributes */
  62    for (i = 0; i < num_attribs; i++) {
  63       velements[i].src_offset = i * 4 * sizeof(float);
  64       velements[i].instance_divisor = 0;
  65       velements[i].vertex_buffer_index = 0;
  66       velements[i].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
  67       velements[i].nr_components = 4;
  68    }
  69    pipe->set_vertex_elements(pipe, num_attribs, velements);
  70
  71    /* draw */
  72    pipe->draw_arrays(pipe, prim_type, 0, num_verts);
  73 }
  74
  75
  76
  77 /**
  78  * Draw screen-aligned textured quad.
  79  * Note: this function allocs/destroys a vertex buffer and isn't especially
  80  * efficient.
  81  */
  82 void
  83 util_draw_texquad(struct pipe_context *pipe,
  84                   float x0, float y0, float x1, float y1, float z)
  85 {
  86    struct pipe_buffer *vbuf;
  87    uint numAttribs = 2, vertexBytes, i, j;
  88
  89    vertexBytes = 4 * (4 * numAttribs * sizeof(float));
  90
  91    /* XXX create one-time */
  92    vbuf = pipe_buffer_create(pipe->screen, 32,
  93                              PIPE_BUFFER_USAGE_VERTEX, vertexBytes);
  94    if (vbuf) {
  95       float *v = (float *) pipe_buffer_map(pipe->screen, vbuf,
  96                                            PIPE_BUFFER_USAGE_CPU_WRITE);
  97       if (v) {
  98          /*
  99           * Load vertex buffer
 100           */
 101          for (i = j = 0; i < 4; i++) {
 102             v[j + 2] = z;   /* z */
 103             v[j + 3] = 1.0; /* w */
 104             v[j + 6] = 0.0; /* r */
 105             v[j + 7] = 1.0; /* q */
 106             j += 8;
 107          }
 108
 109          v[0] = x0;
 110          v[1] = y0;
 111          v[4] = 0.0; /*s*/
 112          v[5] = 0.0; /*t*/
 113
 114          v[8] = x1;
 115          v[9] = y0;
 116          v[12] = 1.0;
 117          v[13] = 0.0;
 118
 119          v[16] = x1;
 120          v[17] = y1;
 121          v[20] = 1.0;
 122          v[21] = 1.0;
 123
 124          v[24] = x0;
 125          v[25] = y1;
 126          v[28] = 0.0;
 127          v[29] = 1.0;
 128
 129          pipe_buffer_unmap(pipe->screen, vbuf);
 130          util_draw_vertex_buffer(pipe, vbuf, 0, PIPE_PRIM_TRIANGLE_FAN, 4, 2);
 131       }
 132
 133       pipe_buffer_reference(&vbuf, NULL);
 134    }
 135 }