1/*
2Copyright (c) 2013, Broadcom Europe Ltd
3Copyright (c) 2013, Tim Gover
4All rights reserved.
5
6
7Redistribution and use in source and binary forms, with or without
8modification, are permitted provided that the following conditions are met:
9 * Redistributions of source code must retain the above copyright
10 notice, this list of conditions and the following disclaimer.
11 * Redistributions in binary form must reproduce the above copyright
12 notice, this list of conditions and the following disclaimer in the
13 documentation and/or other materials provided with the distribution.
14 * Neither the name of the copyright holder nor the
15 names of its contributors may be used to endorse or promote products
16 derived from this software without specific prior written permission.
17
18THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
19ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
22DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
25ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
27SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28*/
29
30#include "yuv.h"
31#include "RaspiTex.h"
32#include "RaspiTexUtil.h"
33#include <GLES2/gl2.h>
34#include <EGL/egl.h>
35#include <EGL/eglext.h>
36
37/* Draw a scaled quad showing the the entire texture with the
38 * origin defined as an attribute */
39static RASPITEXUTIL_SHADER_PROGRAM_T yuv_shader =
40{
41 .vertex_source =
42 "attribute vec2 vertex;\n"
43 "attribute vec2 top_left;\n"
44 "varying vec2 texcoord;\n"
45 "void main(void) {\n"
46 " texcoord = vertex + vec2(0.0, 1.0);\n"
47 " gl_Position = vec4(top_left + vertex, 0.0, 1.0);\n"
48 "}\n",
49
50 .fragment_source =
51 "#extension GL_OES_EGL_image_external : require\n"
52 "uniform samplerExternalOES tex;\n"
53 "varying vec2 texcoord;\n"
54 "void main(void) {\n"
55 " gl_FragColor = texture2D(tex, texcoord);\n"
56 "}\n",
57 .uniform_names = {"tex"},
58 .attribute_names = {"vertex", "top_left"},
59};
60
61static GLfloat varray[] =
62{
63 0.0f, 0.0f, 0.0f, -1.0f, 1.0f, -1.0f,
64 1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 0.0f,
65};
66
67static const EGLint yuv_egl_config_attribs[] =
68{
69 EGL_RED_SIZE, 8,
70 EGL_GREEN_SIZE, 8,
71 EGL_BLUE_SIZE, 8,
72 EGL_ALPHA_SIZE, 8,
73 EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
74 EGL_NONE
75};
76
77/**
78 * Creates the OpenGL ES 2.X context and builds the shaders.
79 * @param raspitex_state A pointer to the GL preview state.
80 * @return Zero if successful.
81 */
82static int yuv_init(RASPITEX_STATE *state)
83{
84 int rc;
85 state->egl_config_attribs = yuv_egl_config_attribs;
86 rc = raspitexutil_gl_init_2_0(state);
87 if (rc != 0)
88 goto end;
89
90 rc = raspitexutil_build_shader_program(&yuv_shader);
91 GLCHK(glUseProgram(yuv_shader.program));
92 GLCHK(glUniform1i(yuv_shader.uniform_locations[0], 0)); // tex unit
93end:
94 return rc;
95}
96
97/**
98 * Draws a 2x2 grid with each shell showing the entire MMAL buffer from a
99 * different EGL image target.
100 */
101static int yuv_redraw(RASPITEX_STATE *raspitex_state)
102{
103 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
104
105 GLCHK(glUseProgram(yuv_shader.program));
106 GLCHK(glActiveTexture(GL_TEXTURE0));
107 GLCHK(glEnableVertexAttribArray(yuv_shader.attribute_locations[0]));
108 GLCHK(glVertexAttribPointer(yuv_shader.attribute_locations[0],
109 2, GL_FLOAT, GL_FALSE, 0, varray));
110
111 // Y plane
112 GLCHK(glBindTexture(GL_TEXTURE_EXTERNAL_OES, raspitex_state->y_texture));
113 GLCHK(glVertexAttrib2f(yuv_shader.attribute_locations[1], -1.0f, 1.0f));
114 GLCHK(glDrawArrays(GL_TRIANGLES, 0, 6));
115
116 // U plane
117 GLCHK(glBindTexture(GL_TEXTURE_EXTERNAL_OES, raspitex_state->u_texture));
118 GLCHK(glVertexAttrib2f(yuv_shader.attribute_locations[1], 0.0f, 1.0f));
119 GLCHK(glDrawArrays(GL_TRIANGLES, 0, 6));
120
121 // V plane
122 GLCHK(glBindTexture(GL_TEXTURE_EXTERNAL_OES, raspitex_state->v_texture));
123 GLCHK(glVertexAttrib2f(yuv_shader.attribute_locations[1], 0.0f, 0.0f));
124 GLCHK(glDrawArrays(GL_TRIANGLES, 0, 6));
125
126 // RGB plane
127 GLCHK(glBindTexture(GL_TEXTURE_EXTERNAL_OES, raspitex_state->texture));
128 GLCHK(glVertexAttrib2f(yuv_shader.attribute_locations[1], -1.0f, 0.0f));
129 GLCHK(glDrawArrays(GL_TRIANGLES, 0, 6));
130
131 GLCHK(glDisableVertexAttribArray(yuv_shader.attribute_locations[0]));
132 GLCHK(glUseProgram(0));
133 return 0;
134}
135
136int yuv_open(RASPITEX_STATE *state)
137{
138 state->ops.gl_init = yuv_init;
139 state->ops.redraw = yuv_redraw;
140 state->ops.update_texture = raspitexutil_update_texture;
141 state->ops.update_y_texture = raspitexutil_update_y_texture;
142 state->ops.update_u_texture = raspitexutil_update_u_texture;
143 state->ops.update_v_texture = raspitexutil_update_v_texture;
144 return 0;
145}
146