gstreamer/gst-libs/gst/gl/gstglshaderstrings.c

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/*
* GStreamer
* Copyright (C) 2015 Matthew Waters <matthew@centricular.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstglshaderstrings.h"
#define MEDIUMP_PRECISION \
"#ifdef GL_ES\n" \
"precision mediump float;\n" \
"#endif\n"
#define HIGHP_PRECISION \
"#ifdef GL_ES\n" \
"precision highp float;\n" \
"#endif\n"
/* *INDENT-OFF* */
const gchar *gst_gl_shader_string_fragment_mediump_precision =
MEDIUMP_PRECISION;
const gchar *gst_gl_shader_string_fragment_highp_precision =
HIGHP_PRECISION;
const gchar *gst_gl_shader_string_vertex_default =
"attribute vec4 a_position;\n"
"attribute vec2 a_texcoord;\n"
"varying vec2 v_texcoord;\n"
"void main()\n"
"{\n"
" gl_Position = a_position;\n"
" v_texcoord = a_texcoord;\n"
"}\n";
const gchar *gst_gl_shader_string_vertex_mat4_texture_transform =
"uniform mat4 u_transformation;\n"
"attribute vec4 a_position;\n"
"attribute vec2 a_texcoord;\n"
"varying vec2 v_texcoord;\n"
"void main()\n"
"{\n"
" gl_Position = a_position;\n"
" v_texcoord = (u_transformation * vec4(a_texcoord, 0, 1)).xy;\n"
"}\n";
const gchar *gst_gl_shader_string_vertex_mat4_vertex_transform =
"uniform mat4 u_transformation;\n"
"attribute vec4 a_position;\n"
"attribute vec2 a_texcoord;\n"
"varying vec2 v_texcoord;\n"
"void main()\n"
"{\n"
" gl_Position = u_transformation * a_position;\n"
" v_texcoord = a_texcoord;\n"
"}\n";
#define DEFAULT_FRAGMENT_BODY \
"varying vec2 v_texcoord;\n" \
"uniform sampler2D tex;\n" \
"void main()\n" \
"{\n" \
" gl_FragColor = texture2D(tex, v_texcoord);\n" \
"}"
const gchar *gst_gl_shader_string_fragment_default =
MEDIUMP_PRECISION
DEFAULT_FRAGMENT_BODY;
#define EXTERNAL_FRAGMENT_BODY \
"#extension GL_OES_EGL_image_external : require\n" \
"varying vec2 v_texcoord;\n" \
"uniform samplerExternalOES tex;\n" \
"void main()\n" \
"{\n" \
" gl_FragColor = texture2D(tex, v_texcoord);\n" \
"}"
const gchar *gst_gl_shader_string_fragment_external_oes_default =
MEDIUMP_PRECISION
EXTERNAL_FRAGMENT_BODY;
/* *INDENT-ON* */
/**
* gst_gl_shader_string_get_highest_precision:
* @context: a #GstGLContext
* @version: a #GstGLSLVersion
* @profile: a #GstGLSLProfile
*
* Generates a shader string that defines the precision of float types in
* GLSL shaders. This is particularly needed for fragment shaders in a
* GLSL ES context where there is no default precision specified.
*
* Practically, this will return the string 'precision mediump float'
* or 'precision highp float' depending on if high precision floats are
* determined to be supported.
*
* Returns: a shader string defining the precision of float types based on
* @context, @version and @profile
*/
const gchar *
gst_gl_shader_string_get_highest_precision (GstGLContext * context,
GstGLSLVersion version, GstGLSLProfile profile)
{
if (gst_gl_context_supports_precision (context, version, profile)) {
if (gst_gl_context_supports_precision_highp (context, version, profile))
return gst_gl_shader_string_fragment_highp_precision;
else
return gst_gl_shader_string_fragment_mediump_precision;
}
return "";
}
/**
* gst_gl_shader_string_fragment_get_default:
* @context: a #GstGLContext
* @version: a #GstGLSLVersion
* @profile: a #GstGLSLProfile
*
* Returns: a passthrough shader string for copying an input texture to
* the output
*/
gchar *
gst_gl_shader_string_fragment_get_default (GstGLContext * context,
GstGLSLVersion version, GstGLSLProfile profile)
{
const gchar *precision =
gst_gl_shader_string_get_highest_precision (context, version, profile);
return g_strdup_printf ("%s%s", precision, DEFAULT_FRAGMENT_BODY);
}
/**
* gst_gl_shader_string_fragment_external_oes_get_default:
* @context: a #GstGLContext
* @version: a #GstGLSLVersion
* @profile: a #GstGLSLProfile
*
* Returns: a passthrough shader string for copying an input external-oes
* texture to the output
*/
gchar *
gst_gl_shader_string_fragment_external_oes_get_default (GstGLContext * context,
GstGLSLVersion version, GstGLSLProfile profile)
{
const gchar *precision =
gst_gl_shader_string_get_highest_precision (context, version, profile);
return g_strdup_printf ("%s%s", precision, EXTERNAL_FRAGMENT_BODY);
}