u_draw_quad.c revision 044d583ba12689cbe99098eb999854303de57f59 
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 a simple vertex buffer / primitive.
38 * Limited to float[4] vertex attribs, tightly packed.
39 */
40void
41util_draw_vertex_buffer(struct pipe_context *pipe,
42                        struct pipe_buffer *vbuf,
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   vbuffer.buffer = vbuf;
55   vbuffer.pitch = num_attribs * 4 * sizeof(float);  /* vertex size */
56   vbuffer.buffer_offset = 0;
57   pipe->set_vertex_buffers(pipe, 1, &vbuffer);
58
59   /* tell pipe about the vertex attributes */
60   for (i = 0; i < num_attribs; i++) {
61      velements[i].src_offset = i * 4 * sizeof(float);
62      velements[i].vertex_buffer_index = 0;
63      velements[i].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
64      velements[i].nr_components = 4;
65   }
66   pipe->set_vertex_elements(pipe, num_attribs, velements);
67
68   /* draw */
69   pipe->draw_arrays(pipe, prim_type, 0, num_verts);
70}
71
72
73
74/**
75 * Draw screen-aligned textured quad.
76 * Note: this function allocs/destroys a vertex buffer and isn't especially
77 * efficient.
78 */
79void
80util_draw_texquad(struct pipe_context *pipe,
81                  float x0, float y0, float x1, float y1, float z)
82{
83   struct pipe_buffer *vbuf;
84   uint numAttribs = 2, vertexBytes, i, j;
85
86   vertexBytes = 4 * (4 * numAttribs * sizeof(float));
87
88   /* XXX create one-time */
89   vbuf = pipe->winsys->buffer_create(pipe->winsys, 32,
90                                      PIPE_BUFFER_USAGE_VERTEX, vertexBytes);
91   if (vbuf) {
92      float *v = (float *) pipe->winsys->buffer_map(pipe->winsys, vbuf,
93                                             PIPE_BUFFER_USAGE_CPU_WRITE);
94      if (v) {
95         /*
96          * Load vertex buffer
97          */
98         for (i = j = 0; i < 4; i++) {
99            v[j + 2] = z;   /* z */
100            v[j + 3] = 1.0; /* w */
101            v[j + 6] = 0.0; /* r */
102            v[j + 7] = 1.0; /* q */
103            j += 8;
104         }
105
106         v[0] = x0;
107         v[1] = y0;
108         v[4] = 0.0; /*s*/
109         v[5] = 0.0; /*t*/
110
111         v[8] = x1;
112         v[9] = y0;
113         v[12] = 1.0;
114         v[13] = 0.0;
115
116         v[16] = x1;
117         v[17] = y1;
118         v[20] = 1.0;
119         v[21] = 1.0;
120
121         v[24] = x0;
122         v[25] = y1;
123         v[28] = 0.0;
124         v[29] = 1.0;
125
126         pipe->winsys->buffer_unmap(pipe->winsys, vbuf);
127         util_draw_vertex_buffer(pipe, vbuf, PIPE_PRIM_TRIANGLE_FAN, 4, 2);
128      }
129
130      pipe_buffer_reference(pipe->winsys, &vbuf, NULL);
131   }
132}
133