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 void qemu_gl_run_texture_blit(GLint texture_blit_prog) 33 { 34 GLfloat in_position[] = { 35 -1, -1, 36 1, -1, 37 -1, 1, 38 1, 1, 39 }; 40 GLint l_position; 41 42 glUseProgram(texture_blit_prog); 43 l_position = glGetAttribLocation(texture_blit_prog, "in_position"); 44 glVertexAttribPointer(l_position, 2, GL_FLOAT, GL_FALSE, 0, in_position); 45 glEnableVertexAttribArray(l_position); 46 glDrawArrays(GL_TRIANGLE_STRIP, l_position, 4); 47 } 48 49 /* ---------------------------------------------------------------------- */ 50 51 GLuint qemu_gl_create_compile_shader(GLenum type, const GLchar *src) 52 { 53 GLuint shader; 54 GLint status, length; 55 char *errmsg; 56 57 shader = glCreateShader(type); 58 glShaderSource(shader, 1, &src, 0); 59 glCompileShader(shader); 60 61 glGetShaderiv(shader, GL_COMPILE_STATUS, &status); 62 if (!status) { 63 glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &length); 64 errmsg = malloc(length); 65 glGetShaderInfoLog(shader, length, &length, errmsg); 66 fprintf(stderr, "%s: compile %s error\n%s\n", __func__, 67 (type == GL_VERTEX_SHADER) ? "vertex" : "fragment", 68 errmsg); 69 free(errmsg); 70 return 0; 71 } 72 return shader; 73 } 74 75 GLuint qemu_gl_create_link_program(GLuint vert, GLuint frag) 76 { 77 GLuint program; 78 GLint status, length; 79 char *errmsg; 80 81 program = glCreateProgram(); 82 glAttachShader(program, vert); 83 glAttachShader(program, frag); 84 glLinkProgram(program); 85 86 glGetProgramiv(program, GL_LINK_STATUS, &status); 87 if (!status) { 88 glGetProgramiv(program, GL_INFO_LOG_LENGTH, &length); 89 errmsg = malloc(length); 90 glGetProgramInfoLog(program, length, &length, errmsg); 91 fprintf(stderr, "%s: link program: %s\n", __func__, errmsg); 92 free(errmsg); 93 return 0; 94 } 95 return program; 96 } 97 98 GLuint qemu_gl_create_compile_link_program(const GLchar *vert_src, 99 const GLchar *frag_src) 100 { 101 GLuint vert_shader, frag_shader, program; 102 103 vert_shader = qemu_gl_create_compile_shader(GL_VERTEX_SHADER, vert_src); 104 frag_shader = qemu_gl_create_compile_shader(GL_FRAGMENT_SHADER, frag_src); 105 if (!vert_shader || !frag_shader) { 106 return 0; 107 } 108 109 program = qemu_gl_create_link_program(vert_shader, frag_shader); 110 glDeleteShader(vert_shader); 111 glDeleteShader(frag_shader); 112 113 return program; 114 } 115