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/osdep.h" 28 #include "ui/shader.h" 29 30 #include "shader/texture-blit-vert.h" 31 #include "shader/texture-blit-flip-vert.h" 32 #include "shader/texture-blit-frag.h" 33 34 struct QemuGLShader { 35 GLint texture_blit_prog; 36 GLint texture_blit_flip_prog; 37 GLint texture_blit_vao; 38 }; 39 40 /* ---------------------------------------------------------------------- */ 41 42 static GLuint qemu_gl_init_texture_blit(GLint texture_blit_prog) 43 { 44 static const GLfloat in_position[] = { 45 -1, -1, 46 1, -1, 47 -1, 1, 48 1, 1, 49 }; 50 GLint l_position; 51 GLuint vao, buffer; 52 53 glGenVertexArrays(1, &vao); 54 glBindVertexArray(vao); 55 56 /* this is the VBO that holds the vertex data */ 57 glGenBuffers(1, &buffer); 58 glBindBuffer(GL_ARRAY_BUFFER, buffer); 59 glBufferData(GL_ARRAY_BUFFER, sizeof(in_position), in_position, 60 GL_STATIC_DRAW); 61 62 l_position = glGetAttribLocation(texture_blit_prog, "in_position"); 63 glVertexAttribPointer(l_position, 2, GL_FLOAT, GL_FALSE, 0, 0); 64 glEnableVertexAttribArray(l_position); 65 66 glBindBuffer(GL_ARRAY_BUFFER, 0); 67 glBindVertexArray(0); 68 69 return vao; 70 } 71 72 void qemu_gl_run_texture_blit(QemuGLShader *gls, bool flip) 73 { 74 glUseProgram(flip 75 ? gls->texture_blit_flip_prog 76 : gls->texture_blit_prog); 77 glBindVertexArray(gls->texture_blit_vao); 78 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); 79 } 80 81 /* ---------------------------------------------------------------------- */ 82 83 static GLuint qemu_gl_create_compile_shader(GLenum type, const GLchar *src) 84 { 85 GLuint shader; 86 GLint status, length; 87 char *errmsg; 88 89 shader = glCreateShader(type); 90 glShaderSource(shader, 1, &src, 0); 91 glCompileShader(shader); 92 93 glGetShaderiv(shader, GL_COMPILE_STATUS, &status); 94 if (!status) { 95 glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &length); 96 errmsg = g_malloc(length); 97 glGetShaderInfoLog(shader, length, &length, errmsg); 98 fprintf(stderr, "%s: compile %s error\n%s\n", __func__, 99 (type == GL_VERTEX_SHADER) ? "vertex" : "fragment", 100 errmsg); 101 g_free(errmsg); 102 return 0; 103 } 104 return shader; 105 } 106 107 static GLuint qemu_gl_create_link_program(GLuint vert, GLuint frag) 108 { 109 GLuint program; 110 GLint status, length; 111 char *errmsg; 112 113 program = glCreateProgram(); 114 glAttachShader(program, vert); 115 glAttachShader(program, frag); 116 glLinkProgram(program); 117 118 glGetProgramiv(program, GL_LINK_STATUS, &status); 119 if (!status) { 120 glGetProgramiv(program, GL_INFO_LOG_LENGTH, &length); 121 errmsg = g_malloc(length); 122 glGetProgramInfoLog(program, length, &length, errmsg); 123 fprintf(stderr, "%s: link program: %s\n", __func__, errmsg); 124 g_free(errmsg); 125 return 0; 126 } 127 return program; 128 } 129 130 static GLuint qemu_gl_create_compile_link_program(const GLchar *vert_src, 131 const GLchar *frag_src) 132 { 133 GLuint vert_shader, frag_shader, program; 134 135 vert_shader = qemu_gl_create_compile_shader(GL_VERTEX_SHADER, vert_src); 136 frag_shader = qemu_gl_create_compile_shader(GL_FRAGMENT_SHADER, frag_src); 137 if (!vert_shader || !frag_shader) { 138 return 0; 139 } 140 141 program = qemu_gl_create_link_program(vert_shader, frag_shader); 142 glDeleteShader(vert_shader); 143 glDeleteShader(frag_shader); 144 145 return program; 146 } 147 148 /* ---------------------------------------------------------------------- */ 149 150 QemuGLShader *qemu_gl_init_shader(void) 151 { 152 QemuGLShader *gls = g_new0(QemuGLShader, 1); 153 154 gls->texture_blit_prog = qemu_gl_create_compile_link_program 155 (texture_blit_vert_src, texture_blit_frag_src); 156 gls->texture_blit_flip_prog = qemu_gl_create_compile_link_program 157 (texture_blit_flip_vert_src, texture_blit_frag_src); 158 if (!gls->texture_blit_prog || !gls->texture_blit_flip_prog) { 159 exit(1); 160 } 161 162 gls->texture_blit_vao = 163 qemu_gl_init_texture_blit(gls->texture_blit_prog); 164 165 return gls; 166 } 167 168 void qemu_gl_fini_shader(QemuGLShader *gls) 169 { 170 if (!gls) { 171 return; 172 } 173 g_free(gls); 174 } 175