/*
 *  Copyright (C) 2007-2018 Team Kodi
 *  This file is part of Kodi - https://kodi.tv
 *
 *  SPDX-License-Identifier: GPL-2.0-or-later
 *  See LICENSES/README.md for more information.
 */

#pragma once

#include "system_gl.h"
#include "guilib/Shader.h"
#include "cores/VideoSettings.h"
#include "GLSLOutput.h"

namespace Shaders {

  class BaseVideoFilterShader : public CGLSLShaderProgram
  {
  public:
    BaseVideoFilterShader();
    virtual ~BaseVideoFilterShader();
    virtual bool GetTextureFilter(GLint& filter) { return false; }

    void SetSourceTexture(GLint ytex) { m_sourceTexUnit = ytex; }
    void SetWidth(int w) { m_width  = w; m_stepX = w>0?1.0f/w:0; }
    void SetHeight(int h) { m_height = h; m_stepY = h>0?1.0f/h:0; }
    void SetNonLinStretch(float stretch) { m_stretch = stretch; }
    void SetAlpha(GLfloat alpha) { m_alpha= alpha; }

    GLint GetVertexLoc() { return m_hVertex; }
    GLint GetCoordLoc() { return m_hCoord; }

    void SetMatrices(const GLfloat *p, const GLfloat *m) { m_proj = p; m_model = m; }

  protected:
    int m_width;
    int m_height;
    float m_stepX;
    float m_stepY;
    float m_stretch;
    GLfloat m_alpha;
    GLint m_sourceTexUnit;
    const GLfloat *m_proj = nullptr;
    const GLfloat *m_model = nullptr;

    // shader attribute handles
    GLint m_hSourceTex;
    GLint m_hStepXY;
    GLint m_hStretch = -1;
    GLint m_hAlpha = -1;
    GLint m_hVertex = -1;
    GLint m_hCoord = -1;
    GLint m_hProj = -1;
    GLint m_hModel = -1;
  };

  class ConvolutionFilterShader : public BaseVideoFilterShader
  {
  public:
    ConvolutionFilterShader(ESCALINGMETHOD method, bool stretch, GLSLOutput *output=NULL);
    ~ConvolutionFilterShader() override;
    void OnCompiledAndLinked() override;
    bool OnEnabled() override;
    void OnDisabled() override;
    void Free();

    bool GetTextureFilter(GLint& filter) override { filter = GL_NEAREST; return true; }

  protected:
    // kernel textures
    GLuint m_kernelTex1;

    // shader handles to kernel textures
    GLint m_hKernTex;

    ESCALINGMETHOD m_method;
    bool m_floattex; //if float textures are supported
    GLint m_internalformat;

    Shaders::GLSLOutput *m_glslOutput;
  };

  class StretchFilterShader : public BaseVideoFilterShader
  {
    public:
      StretchFilterShader();
      void OnCompiledAndLinked() override;
      bool OnEnabled() override;
  };

  class DefaultFilterShader : public BaseVideoFilterShader
  {
    public:
      void OnCompiledAndLinked() override;
      bool OnEnabled() override;
  };

} // end namespace


