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oak-editor/app/render/backend/opengl/openglshader.cpp
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/***
Olive - Non-Linear Video Editor
Copyright (C) 2019 Olive Team
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
***/
#include "openglshader.h"
#include <QOpenGLExtraFunctions>
OLIVE_NAMESPACE_ENTER
OpenGLShaderPtr OpenGLShader::Create()
{
return std::make_shared<OpenGLShader>();
}
OpenGLShaderPtr OpenGLShader::CreateDefault(const QString &function_name, const QString &shader_code)
{
OpenGLShaderPtr program = Create();
// Add shaders to program
program->addShaderFromSourceCode(QOpenGLShader::Vertex, CodeDefaultVertex());
program->addShaderFromSourceCode(QOpenGLShader::Fragment, CodeDefaultFragment(function_name, shader_code));
program->link();
return program;
}
// copied from source code to OCIODisplay
const int OCIO_LUT3D_EDGE_SIZE = 64;
// copied from source code to OCIODisplay, expanded from 3*LUT3D_EDGE_SIZE*LUT3D_EDGE_SIZE*LUT3D_EDGE_SIZE
const int OCIO_NUM_3D_ENTRIES = 3*OCIO_LUT3D_EDGE_SIZE*OCIO_LUT3D_EDGE_SIZE*OCIO_LUT3D_EDGE_SIZE;
OpenGLShaderPtr OpenGLShader::CreateOCIO(QOpenGLContext* ctx,
GLuint& lut_texture,
OCIO::ConstProcessorRcPtr processor,
bool alpha_is_associated)
{
QOpenGLExtraFunctions* xf = ctx->extraFunctions();
// Set up shader description
OCIO::GpuShaderDesc shaderDesc;
const char* ocio_func_name = "OCIODisplay";
shaderDesc.setLanguage(OCIO::GPU_LANGUAGE_GLSL_1_3);
shaderDesc.setFunctionName(ocio_func_name);
shaderDesc.setLut3DEdgeLen(OCIO_LUT3D_EDGE_SIZE);
// Compute LUT
std::vector<float> ocio_lut_data(OCIO_NUM_3D_ENTRIES);
processor->getGpuLut3D(&ocio_lut_data[0], shaderDesc);
// Create LUT texture
xf->glGenTextures(1, &lut_texture);
// Bind LUT
xf->glActiveTexture(GL_TEXTURE1);
xf->glBindTexture(GL_TEXTURE_3D, lut_texture);
// Set texture parameters
xf->glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
xf->glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
xf->glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
xf->glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
xf->glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
// Allocate storage for texture
xf->glTexImage3D(GL_TEXTURE_3D, 0, GL_RGB16F,
OCIO_LUT3D_EDGE_SIZE, OCIO_LUT3D_EDGE_SIZE, OCIO_LUT3D_EDGE_SIZE,
0, GL_RGB, GL_FLOAT, &ocio_lut_data[0]);
// Create OCIO shader code
QString shader_text;
// Workaround since OCIO doesn't support the GLSL version we use
shader_text.append(QStringLiteral("#define texture2D texture\n"
"#define texture3D texture\n"));
// Append OCIO shader code
shader_text.append(processor->getGpuShaderText(shaderDesc));
QString shader_call;
// Enforce alpha association
if (alpha_is_associated) {
// If alpha is already associated, we'll need to disassociate and reassociate
shader_text.append("\n");
QString disassociate_func_name = "disassoc";
shader_text.append(CodeAlphaDisassociate(disassociate_func_name));
QString reassociate_func_name = "reassoc";
shader_text.append(CodeAlphaReassociate(reassociate_func_name));
// Make OCIO call pass through disassociate and reassociate function
shader_call = QStringLiteral("%3(%1(%2(col), ove_ociolut));").arg(ocio_func_name,
disassociate_func_name,
reassociate_func_name);
} else {
// If alpha is not already associated, we can just associate after OCIO
// Add associate function
QString associate_func_name = "assoc";
shader_text.append(CodeAlphaAssociate(associate_func_name));
// Make OCIO call pass through associate function
shader_call = QStringLiteral("%2(%1(col, ove_ociolut));").arg(ocio_func_name, associate_func_name);
}
// Add process() function, which GetPipeline() will call if specified
QString process_function_name = "process";
shader_text.append(QStringLiteral("\n"
"uniform sampler3D ove_ociolut;\n"
"\n"
"vec4 %2(vec4 col) {\n"
" return %1\n"
"}\n").arg(shader_call, process_function_name));
// Get pipeline-based shader to inject OCIO shader into
OpenGLShaderPtr shader = OpenGLShader::CreateDefault(process_function_name, shader_text);
// Release LUT
xf->glBindTexture(GL_TEXTURE_3D, 0);
xf->glActiveTexture(GL_TEXTURE0);
return shader;
}
QString OpenGLShader::CodeDefaultFragment(QString function_name, const QString &shader_code)
{
// Create shader header
QString frag_code = QStringLiteral("#version 150\n"
"\n"
"#ifdef GL_ES\n"
"precision highp int;\n"
"precision highp float;\n"
"#endif\n"
"\n"
"uniform sampler2D ove_maintex;\n"
"uniform vec2 ove_resolution;\n"
"uniform bool ove_deinterlace;\n"
"\n"
"in vec2 ove_texcoord;\n"
"\n"
"out vec4 fragColor;\n"
"\n");
// Check if additional code was passed to this function, add it here
if (!function_name.isEmpty() && !shader_code.isEmpty()) {
// If additional code was passed, add it and reference it in main().
//
// The function in the additional code is expected to be `vec4 function_name(vec4 color)`.
// The texture coordinate can be acquired through `ove_texcoord`.
frag_code.append(shader_code);
} else {
// No function to call
function_name = QString();
}
// Our function_name arg will either resolve to the function added to this or to nothing, in
// which case they'll just be benign brackets.
frag_code.append(QStringLiteral("\n"
"void main() {\n"
" vec2 using_texcoord = ove_texcoord;\n"
" if (ove_deinterlace) {\n"
" // A very basic deinterlace that halves the vertical\n"
" // resolution and linearly interpolates the two fields\n"
" // by reading the texture coord between them.\n"
" float half_vert = round(ove_resolution.y / 2.0);\n"
" using_texcoord.y = (round(using_texcoord.y * half_vert) + 0.25) / half_vert;\n"
" }\n"
" vec4 color = %1(texture(ove_maintex, using_texcoord));\n"
" fragColor = color;\n"
"}\n").arg(function_name));
return frag_code;
}
QString OpenGLShader::CodeDefaultVertex()
{
// Generate vertex shader
return QStringLiteral("#version 150\n"
"\n"
"#ifdef GL_ES\n"
"precision highp int;\n"
"precision highp float;\n"
"#endif\n"
"\n"
"uniform mat4 ove_mvpmat;\n"
"\n"
"in vec4 a_position;\n"
"in vec2 a_texcoord;\n"
"\n"
"out vec2 ove_texcoord;\n"
"\n"
"void main() {\n"
" gl_Position = ove_mvpmat * a_position;\n"
" ove_texcoord = a_texcoord;\n"
"}\n");
}
QString OpenGLShader::CodeAlphaDisassociate(const QString &function_name)
{
return QStringLiteral("vec4 %1(vec4 col) {\n"
" if (col.a > 0.0) {\n"
" return vec4(col.rgb / col.a, col.a);"
" }\n"
" return col;\n"
"}\n").arg(function_name);
}
QString OpenGLShader::CodeAlphaReassociate(const QString &function_name)
{
return QStringLiteral("vec4 %1(vec4 col) {\n"
" if (col.a > 0.0) {\n"
" return vec4(col.rgb * col.a, col.a);"
" }\n"
" return col;\n"
"}\n").arg(function_name);
}
QString OpenGLShader::CodeAlphaAssociate(const QString &function_name)
{
return QStringLiteral("vec4 %1(vec4 col) {\n"
" return vec4(col.rgb * col.a, col.a);\n"
"}\n").arg(function_name);
}
OLIVE_NAMESPACE_EXIT