]> git.proxmox.com Git - mirror_qemu.git/blob - ui/shader.c
Merge remote-tracking branch 'remotes/armbru/tags/pull-monitor-2015-10-09' into staging
[mirror_qemu.git] / ui / shader.c
1 /*
2 * QEMU opengl shader helper functions
3 *
4 * Copyright (c) 2014 Red Hat
5 *
6 * Authors:
7 * Gerd Hoffmann <kraxel@redhat.com>
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a copy
10 * of this software and associated documentation files (the "Software"), to deal
11 * in the Software without restriction, including without limitation the rights
12 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13 * copies of the Software, and to permit persons to whom the Software is
14 * furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 * THE SOFTWARE.
26 */
27 #include "qemu-common.h"
28 #include "ui/shader.h"
29
30 /* ---------------------------------------------------------------------- */
31
32 GLuint qemu_gl_init_texture_blit(GLint texture_blit_prog)
33 {
34 static const GLfloat in_position[] = {
35 -1, -1,
36 1, -1,
37 -1, 1,
38 1, 1,
39 };
40 GLint l_position;
41 GLuint vao, buffer;
42
43 glGenVertexArrays(1, &vao);
44 glBindVertexArray(vao);
45
46 /* this is the VBO that holds the vertex data */
47 glGenBuffers(1, &buffer);
48 glBindBuffer(GL_ARRAY_BUFFER, buffer);
49 glBufferData(GL_ARRAY_BUFFER, sizeof(in_position), in_position,
50 GL_STATIC_DRAW);
51
52 l_position = glGetAttribLocation(texture_blit_prog, "in_position");
53 glVertexAttribPointer(l_position, 2, GL_FLOAT, GL_FALSE, 0, 0);
54 glEnableVertexAttribArray(l_position);
55
56 glBindBuffer(GL_ARRAY_BUFFER, 0);
57 glBindVertexArray(0);
58
59 return vao;
60 }
61
62 void qemu_gl_run_texture_blit(GLint texture_blit_prog,
63 GLint texture_blit_vao)
64 {
65 glUseProgram(texture_blit_prog);
66 glBindVertexArray(texture_blit_vao);
67 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
68 }
69
70 /* ---------------------------------------------------------------------- */
71
72 GLuint qemu_gl_create_compile_shader(GLenum type, const GLchar *src)
73 {
74 GLuint shader;
75 GLint status, length;
76 char *errmsg;
77
78 shader = glCreateShader(type);
79 glShaderSource(shader, 1, &src, 0);
80 glCompileShader(shader);
81
82 glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
83 if (!status) {
84 glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &length);
85 errmsg = malloc(length);
86 glGetShaderInfoLog(shader, length, &length, errmsg);
87 fprintf(stderr, "%s: compile %s error\n%s\n", __func__,
88 (type == GL_VERTEX_SHADER) ? "vertex" : "fragment",
89 errmsg);
90 free(errmsg);
91 return 0;
92 }
93 return shader;
94 }
95
96 GLuint qemu_gl_create_link_program(GLuint vert, GLuint frag)
97 {
98 GLuint program;
99 GLint status, length;
100 char *errmsg;
101
102 program = glCreateProgram();
103 glAttachShader(program, vert);
104 glAttachShader(program, frag);
105 glLinkProgram(program);
106
107 glGetProgramiv(program, GL_LINK_STATUS, &status);
108 if (!status) {
109 glGetProgramiv(program, GL_INFO_LOG_LENGTH, &length);
110 errmsg = malloc(length);
111 glGetProgramInfoLog(program, length, &length, errmsg);
112 fprintf(stderr, "%s: link program: %s\n", __func__, errmsg);
113 free(errmsg);
114 return 0;
115 }
116 return program;
117 }
118
119 GLuint qemu_gl_create_compile_link_program(const GLchar *vert_src,
120 const GLchar *frag_src)
121 {
122 GLuint vert_shader, frag_shader, program;
123
124 vert_shader = qemu_gl_create_compile_shader(GL_VERTEX_SHADER, vert_src);
125 frag_shader = qemu_gl_create_compile_shader(GL_FRAGMENT_SHADER, frag_src);
126 if (!vert_shader || !frag_shader) {
127 return 0;
128 }
129
130 program = qemu_gl_create_link_program(vert_shader, frag_shader);
131 glDeleteShader(vert_shader);
132 glDeleteShader(frag_shader);
133
134 return program;
135 }