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/*
* Copyright 2017 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#import "RTCDefaultShader.h"
#import <OpenGLES/ES3/gl.h>
#import "RTCOpenGLDefines.h"
#import "RTCShader.h"
#import "base/RTCLogging.h"
#include <optional>
static const int kYTextureUnit = 0;
static const int kUTextureUnit = 1;
static const int kVTextureUnit = 2;
static const int kUvTextureUnit = 1;
// Fragment shader converts YUV values from input textures into a final RGB
// pixel. The conversion formula is from http://www.fourcc.org/fccyvrgb.php.
static const char kI420FragmentShaderSource[] = SHADER_VERSION
"precision highp float;" FRAGMENT_SHADER_IN " vec2 v_texcoord;\n"
"uniform lowp sampler2D s_textureY;\n"
"uniform lowp sampler2D s_textureU;\n"
"uniform lowp sampler2D s_textureV;\n" FRAGMENT_SHADER_OUT "void main() {\n"
" float y, u, v, r, g, b;\n"
" y = " FRAGMENT_SHADER_TEXTURE "(s_textureY, v_texcoord).r;\n"
" u = " FRAGMENT_SHADER_TEXTURE "(s_textureU, v_texcoord).r;\n"
" v = " FRAGMENT_SHADER_TEXTURE "(s_textureV, v_texcoord).r;\n"
" u = u - 0.5;\n"
" v = v - 0.5;\n"
" r = y + 1.403 * v;\n"
" g = y - 0.344 * u - 0.714 * v;\n"
" b = y + 1.770 * u;\n"
" " FRAGMENT_SHADER_COLOR " = vec4(r, g, b, 1.0);\n"
" }\n";
static const char kNV12FragmentShaderSource[] = SHADER_VERSION
"precision mediump float;" FRAGMENT_SHADER_IN " vec2 v_texcoord;\n"
"uniform lowp sampler2D s_textureY;\n"
"uniform lowp sampler2D s_textureUV;\n" FRAGMENT_SHADER_OUT
"void main() {\n"
" mediump float y;\n"
" mediump vec2 uv;\n"
" y = " FRAGMENT_SHADER_TEXTURE "(s_textureY, v_texcoord).r;\n"
" uv = " FRAGMENT_SHADER_TEXTURE "(s_textureUV, v_texcoord).ra -\n"
" vec2(0.5, 0.5);\n"
" " FRAGMENT_SHADER_COLOR " = vec4(y + 1.403 * uv.y,\n"
" y - 0.344 * uv.x - 0.714 * uv.y,\n"
" y + 1.770 * uv.x,\n"
" 1.0);\n"
" }\n";
@implementation RTCDefaultShader {
GLuint _vertexBuffer;
GLuint _vertexArray;
// Store current rotation and only upload new vertex data when rotation
// changes.
std::optional<RTCVideoRotation> _currentRotation;
GLuint _i420Program;
GLuint _nv12Program;
}
- (void)dealloc {
glDeleteProgram(_i420Program);
glDeleteProgram(_nv12Program);
glDeleteBuffers(1, &_vertexBuffer);
glDeleteVertexArrays(1, &_vertexArray);
}
- (BOOL)createAndSetupI420Program {
NSAssert(!_i420Program, @"I420 program already created");
_i420Program = RTCCreateProgramFromFragmentSource(kI420FragmentShaderSource);
if (!_i420Program) {
return NO;
}
GLint ySampler = glGetUniformLocation(_i420Program, "s_textureY");
GLint uSampler = glGetUniformLocation(_i420Program, "s_textureU");
GLint vSampler = glGetUniformLocation(_i420Program, "s_textureV");
if (ySampler < 0 || uSampler < 0 || vSampler < 0) {
RTCLog(@"Failed to get uniform variable locations in I420 shader");
glDeleteProgram(_i420Program);
_i420Program = 0;
return NO;
}
glUseProgram(_i420Program);
glUniform1i(ySampler, kYTextureUnit);
glUniform1i(uSampler, kUTextureUnit);
glUniform1i(vSampler, kVTextureUnit);
return YES;
}
- (BOOL)createAndSetupNV12Program {
NSAssert(!_nv12Program, @"NV12 program already created");
_nv12Program = RTCCreateProgramFromFragmentSource(kNV12FragmentShaderSource);
if (!_nv12Program) {
return NO;
}
GLint ySampler = glGetUniformLocation(_nv12Program, "s_textureY");
GLint uvSampler = glGetUniformLocation(_nv12Program, "s_textureUV");
if (ySampler < 0 || uvSampler < 0) {
RTCLog(@"Failed to get uniform variable locations in NV12 shader");
glDeleteProgram(_nv12Program);
_nv12Program = 0;
return NO;
}
glUseProgram(_nv12Program);
glUniform1i(ySampler, kYTextureUnit);
glUniform1i(uvSampler, kUvTextureUnit);
return YES;
}
- (BOOL)prepareVertexBufferWithRotation:(RTCVideoRotation)rotation {
if (!_vertexBuffer && !RTCCreateVertexBuffer(&_vertexBuffer, &_vertexArray)) {
RTCLog(@"Failed to setup vertex buffer");
return NO;
}
glBindBuffer(GL_ARRAY_BUFFER, _vertexBuffer);
if (!_currentRotation || rotation != *_currentRotation) {
_currentRotation = std::optional<RTCVideoRotation>(rotation);
RTCSetVertexData(*_currentRotation);
}
return YES;
}
- (void)applyShadingForFrameWithWidth:(int)width
height:(int)height
rotation:(RTCVideoRotation)rotation
yPlane:(GLuint)yPlane
uPlane:(GLuint)uPlane
vPlane:(GLuint)vPlane {
if (![self prepareVertexBufferWithRotation:rotation]) {
return;
}
if (!_i420Program && ![self createAndSetupI420Program]) {
RTCLog(@"Failed to setup I420 program");
return;
}
glUseProgram(_i420Program);
glActiveTexture(static_cast<GLenum>(GL_TEXTURE0 + kYTextureUnit));
glBindTexture(GL_TEXTURE_2D, yPlane);
glActiveTexture(static_cast<GLenum>(GL_TEXTURE0 + kUTextureUnit));
glBindTexture(GL_TEXTURE_2D, uPlane);
glActiveTexture(static_cast<GLenum>(GL_TEXTURE0 + kVTextureUnit));
glBindTexture(GL_TEXTURE_2D, vPlane);
glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
}
- (void)applyShadingForFrameWithWidth:(int)width
height:(int)height
rotation:(RTCVideoRotation)rotation
yPlane:(GLuint)yPlane
uvPlane:(GLuint)uvPlane {
if (![self prepareVertexBufferWithRotation:rotation]) {
return;
}
if (!_nv12Program && ![self createAndSetupNV12Program]) {
RTCLog(@"Failed to setup NV12 shader");
return;
}
glUseProgram(_nv12Program);
glActiveTexture(static_cast<GLenum>(GL_TEXTURE0 + kYTextureUnit));
glBindTexture(GL_TEXTURE_2D, yPlane);
glActiveTexture(static_cast<GLenum>(GL_TEXTURE0 + kUvTextureUnit));
glBindTexture(GL_TEXTURE_2D, uvPlane);
glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
}
@end
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