modules/video_output/opengl/gl_util.c

   1 /*****************************************************************************
   2  * gl_util.c
   3  *****************************************************************************
   4  * Copyright (C) 2020 VLC authors and VideoLAN
   5  * Copyright (C) 2020 Videolabs
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU Lesser General Public License as published by
   9  * the Free Software Foundation; either version 2.1 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with this program; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  20  *****************************************************************************/
  21
  22 #ifdef HAVE_CONFIG_H
  23 # include "config.h"
  24 #endif
  25
  26 #include "gl_util.h"
  27
  28 static void
  29 LogShaderErrors(vlc_object_t *obj, const opengl_vtable_t *vt, GLuint id)
  30 {
  31     GLint info_len;
  32     vt->GetShaderiv(id, GL_INFO_LOG_LENGTH, &info_len);
  33     if (info_len > 0)
  34     {
  35         char *info_log = malloc(info_len);
  36         if (info_log)
  37         {
  38             GLsizei written;
  39             vt->GetShaderInfoLog(id, info_len, &written, info_log);
  40             msg_Err(obj, "shader: %s", info_log);
  41             free(info_log);
  42         }
  43     }
  44 }
  45
  46 static void
  47 LogProgramErrors(vlc_object_t *obj, const opengl_vtable_t *vt, GLuint id)
  48 {
  49     GLint info_len;
  50     vt->GetProgramiv(id, GL_INFO_LOG_LENGTH, &info_len);
  51     if (info_len > 0)
  52     {
  53         char *info_log = malloc(info_len);
  54         if (info_log)
  55         {
  56             GLsizei written;
  57             vt->GetProgramInfoLog(id, info_len, &written, info_log);
  58             msg_Err(obj, "program: %s", info_log);
  59             free(info_log);
  60         }
  61     }
  62 }
  63
  64 static GLuint
  65 CreateShader(vlc_object_t *obj, const opengl_vtable_t *vt, GLenum type,
  66              GLsizei count, const GLchar **src)
  67 {
  68     GLuint shader = vt->CreateShader(type);
  69     if (!shader)
  70         return 0;
  71
  72     vt->ShaderSource(shader, count, src, NULL);
  73     vt->CompileShader(shader);
  74
  75     LogShaderErrors(obj, vt, shader);
  76
  77     GLint compiled;
  78     vt->GetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
  79     if (!compiled)
  80     {
  81         msg_Err(obj, "Failed to compile shader");
  82         vt->DeleteShader(shader);
  83         return 0;
  84     }
  85
  86     return shader;
  87 }
  88
  89
  90 GLuint
  91 vlc_gl_BuildProgram(vlc_object_t *obj, const opengl_vtable_t *vt,
  92                     GLsizei vstring_count, const GLchar **vstrings,
  93                     GLsizei fstring_count, const GLchar **fstrings)
  94 {
  95     GLuint program = 0;
  96
  97     GLuint vertex_shader = CreateShader(obj, vt, GL_VERTEX_SHADER,
  98                                         vstring_count, vstrings);
  99     if (!vertex_shader)
 100         return 0;
 101
 102     GLuint fragment_shader = CreateShader(obj, vt, GL_FRAGMENT_SHADER,
 103                                           fstring_count, fstrings);
 104     if (!fragment_shader)
 105         goto finally_1;
 106
 107     program = vt->CreateProgram();
 108     if (!program)
 109         goto finally_2;
 110
 111     vt->AttachShader(program, vertex_shader);
 112     vt->AttachShader(program, fragment_shader);
 113
 114     vt->LinkProgram(program);
 115
 116     LogProgramErrors(obj, vt, program);
 117
 118     GLint linked;
 119     vt->GetProgramiv(program, GL_LINK_STATUS, &linked);
 120     if (!linked)
 121     {
 122         msg_Err(obj, "Failed to link program");
 123         vt->DeleteProgram(program);
 124         program = 0;
 125     }
 126
 127 finally_2:
 128     vt->DeleteShader(fragment_shader);
 129 finally_1:
 130     vt->DeleteShader(vertex_shader);
 131
 132     return program;
 133 }