snes9x/gtk/src/shaders/glsl.cpp

#include "glsl.h"
#include "../../conffile.h"
#include "shader_helpers.h"
#include "../gtk_s9x.h"

static const GLfloat lut_coords[8] = { 0, 0, 1, 0, 1, 1, 0, 1 };
static const GLfloat inv_coords[8] = { 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f };
static const GLfloat tex_coords[8] = { 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f };
static const GLfloat mvp_ortho[16] = { 2.0f,  0.0f,  0.0f,  0.0f,
                                          0.0f,  2.0f,  0.0f,  0.0f,
                                          0.0f,  0.0f, -1.0f,  0.0f,
                                         -1.0f, -1.0f,  0.0f,  1.0f };

static void reduce_to_path(char* filename)
{
    for (int i = strlen(filename); i >= 0; i--)
    {
        if (filename[i] == '\\' || filename[i] == '/')
        {
            filename[i] = 0;
            break;
        }
    }
}

static char* read_file(const char *filename)
{
    FILE* file = NULL;
    int size;
    char* contents;

    file = fopen(filename, "rb");
    if (!file)
        return NULL;

    fseek(file, 0, SEEK_END);
    size = ftell(file);
    fseek(file, 0, SEEK_SET);

    contents = new char[size + 1];
    fread(contents, size, 1, file);
    contents[size] = '\0';
    fclose(file);

    return contents;
}

static int scale_string_to_enum(const char *string, bool last)
{
    if (!strcasecmp(string, "source"))
    {
        return GLSL_SOURCE;
    }
    else if (!strcasecmp(string, "viewport"))
    {
        return GLSL_VIEWPORT;
    }
    else if (!strcasecmp(string, "absolute"))
    {
        return GLSL_ABSOLUTE;
    }
    else if (last)
        return GLSL_VIEWPORT;
    else
        return GLSL_SOURCE;
}

static const char *scale_enum_to_string (int val)
{
    switch (val)
    {
    case GLSL_SOURCE:
        return "source";
    case GLSL_VIEWPORT:
        return "viewport";
    case GLSL_ABSOLUTE:
        return "absolute";
    default:
        return "source";
    }
}

static int wrap_mode_string_to_enum(const char *string)
{
    if (!strcasecmp(string, "repeat"))
    {
        return GL_REPEAT;
    }
    else if (!strcasecmp(string, "clamp_to_edge"))
    {
        return GL_CLAMP_TO_EDGE;
    }
    else if (!strcasecmp(string, "clamp"))
    {
        return GL_CLAMP;
    }
    else
        return GL_CLAMP_TO_BORDER;
}

static const char *wrap_mode_enum_to_string(int val)
{
    switch (val)
    {
    case GL_REPEAT:
        return "repeat";
    case GL_CLAMP_TO_EDGE:
        return "clamp_to_edge";
    case GL_CLAMP:
        return "clamp";
    default:
        return "clamp_to_border";
    }
}


bool GLSLShader::load_shader_file (char *filename)
{
    char key[256];

    if (strlen(filename) < 6 || strcasecmp(&filename[strlen(filename) - 6], ".glslp"))
    {
        GLSLPass pass;
        this->pass.push_back (GLSLPass());

        pass.scale_type_x = pass.scale_type_y = GLSL_VIEWPORT;
        pass.filter = GLSL_UNDEFINED;
        strcpy(pass.filename, filename);
        pass.frame_count_mod = 0;
        pass.frame_count = 0;
        pass.fp = 0;
        pass.scale_x = 1.0;
        pass.scale_y = 1.0;
        this->pass.push_back (pass);

        return true;
    }
    else
    {
        conf.LoadFile(filename);
    }

    int shader_count = conf.GetInt("::shaders", 0);

    if (shader_count < 1)
        return false;

    this->pass.push_back (GLSLPass());

    for (int i = 0; i < shader_count; i++)
    {
        GLSLPass pass;

        snprintf(key, 256, "::filter_linear%u", i);
        pass.filter = conf.Exists(key) ? (conf.GetBool(key) ? GL_LINEAR : GL_NEAREST) : GLSL_UNDEFINED;

        sprintf(key, "::scale_type%u", i);
        const char* scaleType = conf.GetString(key, "");

        if (!strcasecmp(scaleType, ""))
        {
            sprintf(key, "::scale_type_x%u", i);
            const char* scaleTypeX = conf.GetString(key, "");
            pass.scale_type_x = scale_string_to_enum(scaleTypeX, i == shader_count - 1);

            sprintf(key, "::scale_type_y%u", i);
            const char* scaleTypeY = conf.GetString(key, "");
            pass.scale_type_y = scale_string_to_enum(scaleTypeY, i == shader_count - 1);
        }
        else
        {
            int scale_type =  scale_string_to_enum(scaleType, i == shader_count - 1);
            pass.scale_type_x = scale_type;
            pass.scale_type_y = scale_type;
        }

        sprintf(key, "::scale%u", i);
        const char* scaleFloat = conf.GetString(key, "");
        if (!strcasecmp(scaleFloat, ""))
        {
            sprintf(key, "::scale_x%u", i);
            const char* scaleFloatX = conf.GetString(key, "1.0");
            pass.scale_x = atof(scaleFloatX);
            sprintf(key, "::scale_y%u", i);
            const char* scaleFloatY = conf.GetString(key, "1.0");
            pass.scale_y = atof(scaleFloatY);
        }
        else
        {
            pass.scale_x = pass.scale_y = atof(scaleFloat);
        }

        sprintf(key, "::shader%u", i);
        strcpy(pass.filename, conf.GetString(key, ""));

        sprintf(key, "::frame_count_mod%u", i);
        pass.frame_count_mod = conf.GetInt(key, 0);

        if (float_texture_available ())
        {
            sprintf(key, "::float_framebuffer%u", i);
            pass.fp = conf.GetBool(key);
        }
        else
            pass.fp = false;

        if (srgb_available ())
        {
            sprintf(key, "::srgb_framebuffer%u", i);
            pass.srgb = conf.GetBool(key);
        }
        else
            pass.srgb = false;

        sprintf(key, "::alias%u", i);
        strcpy(pass.alias, conf.GetString(key, ""));

        this->pass.push_back(pass);
    }

    char* ids = conf.GetStringDup("::textures", "");

    char* id = strtok(ids, ";");

    while (id != NULL)
    {
        GLSLLut lut;

        sprintf(key, "::%s", id);
        strcpy(lut.id, id);
        strcpy(lut.filename, conf.GetString(key, ""));

        sprintf(key, "::%s_wrap_mode", id);
        lut.wrap_mode = wrap_mode_string_to_enum (conf.GetString (key, ""));

        sprintf(key, "::%s_mipmap", id);
        lut.mipmap = conf.GetBool (key);

        sprintf(key, "::%s_linear", id);
        lut.filter = (conf.GetBool(key, false)) ? GL_LINEAR : GL_NEAREST;

        if (lut.mipmap)
        {
            lut.filter = (lut.filter == GL_LINEAR) ? GL_LINEAR_MIPMAP_LINEAR : GL_NEAREST_MIPMAP_NEAREST;
        }

        this->lut.push_back(lut);

        id = strtok(NULL, ";");
    }

    free(ids);

    return true;
}

void GLSLShader::strip_parameter_pragmas(char *buffer)
{
   /* #pragma parameter lines tend to have " characters in them,
    * which is not legal GLSL. */
   char *s = strstr(buffer, "#pragma parameter");

   while (s)
   {
       GLSLParam par;
       unsigned int i;

       sscanf (s, "#pragma parameter %s \"%[^\"]\" %f %f %f %f",
               par.id, par.name, &par.val, &par.min, &par.max, &par.step);

       if (par.step == 0.0f)
           par.step = 1.0f;

       for (i = 0; i < param.size(); i++)
       {
           if (!strcmp(param[i].id, par.id))
               break;
       }
       if (i >= param.size())
           param.push_back (par);

       /* blank out the line */
       while (*s != '\0' && *s != '\n')
          *s++ = ' ';
       s = strstr(s, "#pragma parameter");
   }
}

GLuint GLSLShader::compile_shader(char *program,
                                  const char *aliases,
                                  const char *defines,
                                  GLuint type,
                                  GLuint *out)
{
    char info_log[1024];
    char *ptr = program;
    std::string complete_program = "";
    char version[32];
    const char *existing_version = strstr(ptr, "#version");

    if (existing_version)
    {
        unsigned version_no = (unsigned) strtoul (existing_version + 8, &ptr, 10);
        snprintf (version, 32, "#version %u\n", version_no);
    }
    else
    {
        snprintf (version, 32, "#version 150\n");
    }

    complete_program += version;
    complete_program += aliases;
    complete_program += defines;
    complete_program += ptr;

    GLuint shader = glCreateShader (type);
    GLint status;
    GLint length = complete_program.length();
    GLchar *prog = (GLchar *) complete_program.c_str();

    glShaderSource (shader, 1, &prog, &length);
    glCompileShader (shader);
    glGetShaderiv (shader, GL_COMPILE_STATUS, &status);

    glGetShaderInfoLog (shader, 1024, NULL, info_log);
    if (info_log && *info_log)
        printf ("%s\n", info_log);
    *out = shader;

    return status;
}

bool GLSLShader::load_shader (char *filename)
{
    char shader_path[PATH_MAX];
    char temp[PATH_MAX];
    std::string aliases = "";
    GLint status;
    char log[1024];

    if (this->pass.size())
        return false;

    if (!filename || *filename == '\0')
        return false;

    strcpy(shader_path, filename);
    reduce_to_path(shader_path);

    chdir(shader_path);
    if (!load_shader_file(filename))
        return false;

    /*
    for (unsigned int i = 1; i < pass.size(); i++)
    {
        if (pass[i].alias && *pass[i].alias)
        {
            aliases += "#define ";
            aliases += pass[i].alias;
            aliases += " Pass";
            aliases += std::to_string(i - 1);
            aliases += "Texture\n";
            printf ("%s\n", aliases.c_str());
        }
    }*/

    for (unsigned int i = 1; i < pass.size(); i++)
    {
        GLSLPass *p = &pass[i];
        GLuint vertex_shader = 0, fragment_shader = 0;

        realpath(p->filename, temp);
        strcpy (p->filename, temp);

        char *contents = read_file (p->filename);
        if (!contents)
        {
            printf("Couldn't read shader file %s\n", temp);
            return false;
        }

        strip_parameter_pragmas(contents);

        if (!compile_shader (contents,
                             "#define VERTEX\n#define PARAMETER_UNIFORM\n",
                             aliases.c_str(),
                             GL_VERTEX_SHADER,
                             &vertex_shader) || !vertex_shader)
        {
            printf("Couldn't compile vertex shader.\n");
            return false;
        }

        if (!compile_shader (contents,
                             "#define FRAGMENT\n#define PARAMETER_UNIFORM\n",
                             aliases.c_str(),
                             GL_FRAGMENT_SHADER,
                             &fragment_shader) || !fragment_shader)
        {
            printf("Couldn't compile fragment shader\n");
            return false;
        }

        p->program = glCreateProgram ();

        glAttachShader (p->program, vertex_shader);
        glAttachShader (p->program, fragment_shader);

        glLinkProgram (p->program);
        glGetProgramiv (p->program, GL_LINK_STATUS, &status);
        glGetProgramInfoLog(p->program, 1024, NULL, log);
        if (log && *log)
            printf ("%s\n", log);

        glDeleteShader (vertex_shader);
        glDeleteShader (fragment_shader);

        if (status != GL_TRUE)
        {
            printf ("Failed to link program\n");
            glDeleteProgram (p->program);

            return false;
        }

        glGenFramebuffers(1, &p->fbo);
        glGenTextures(1, &p->texture);
        glBindTexture(GL_TEXTURE_2D, p->texture);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

        p->frame_count = 0;
    }

    for (unsigned int i = 0; i < lut.size(); i++)
    {
        GLSLLut *l = &lut[i];
        /* generate texture for the lut and apply specified filter setting
     */
        glGenTextures(1, &l->texture);
        glBindTexture(GL_TEXTURE_2D, l->texture);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, l->wrap_mode);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, l->wrap_mode);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, l->filter);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, l->filter);

        realpath(l->filename, temp);
        strcpy (l->filename, temp);

        // simple file extension png/tga decision
        int length = strlen(temp);
        if (length > 4)
        {
            if (!strcasecmp(&temp[length - 4], ".png"))
            {
                int width, height;
                bool hasAlpha;
                GLubyte* texData;

                if (loadPngImage(temp, width, height, hasAlpha, &texData))
                {
                    glPixelStorei(GL_UNPACK_ROW_LENGTH, width);
                    glTexImage2D(GL_TEXTURE_2D,
                                 0,
                                 GL_RGBA,
                                 width,
                                 height,
                                 0,
                                 hasAlpha ? GL_RGBA : GL_RGB,
                                 GL_UNSIGNED_BYTE,
                                 texData);
                    free(texData);
                }
                else
                {
                    printf ("Failed to load PNG LUT: %s\n", temp);
                }
            }
            else if (!strcasecmp(&temp[length - 4], ".tga"))
            {
                STGA stga;

                if (loadTGA(temp, stga))
                {
                    glPixelStorei(GL_UNPACK_ROW_LENGTH, stga.width);
                    glTexImage2D(GL_TEXTURE_2D,
                                 0,
                                 GL_RGBA,
                                 stga.width,
                                 stga.height,
                                 0,
                                 GL_RGBA,
                                 GL_UNSIGNED_BYTE,
                                 stga.data);
                }
                else
                {
                    printf ("Failed to load TGA LUT: %s\n", temp);
                }
            }
        }

        if (l->mipmap)
            glGenerateMipmap (GL_TEXTURE_2D);
    }

    /* Check for parameters specified in file */
    for (unsigned int i = 0; i < param.size(); i++)
    {
        char key[266];
        const char *value;
        snprintf (key, 266, "::%s", param[i].id);
        value = conf.GetString (key, NULL);
        if (value)
        {
            param[i].val = atof (value);
            param[i].val = CLAMP (param[i].val, param[i].min, param[i].max);
        }
    }

    glActiveTexture(GL_TEXTURE1);
    glEnable(GL_TEXTURE_COORD_ARRAY);
    glTexCoordPointer(2, GL_FLOAT, 0, lut_coords);
    glActiveTexture(GL_TEXTURE0);

    register_uniforms();

    prev_frame.resize (max_prev_frame);

    for (unsigned int i = 0; i < prev_frame.size(); i++)
    {
        glGenTextures(1, &(prev_frame[i].texture));
        prev_frame[i].width = prev_frame[i].height = 0;
    }

    glGenBuffers(1, &vbo);

    frame_count = 0;

    return true;
}

void GLSLShader::render(GLuint &orig, int width, int height, int viewport_width, int viewport_height, int viewport_x, int viewport_y)
{
    frame_count++;

    /* set up our dummy pass for easier loop code
   */
    pass[0].texture = orig;
    pass[0].width = width;
    pass[0].height = height;

    /* loop through all real passes
   */
    for (unsigned int i = 1; i < pass.size(); i++)
    {
        bool lastpass = (i == pass.size() - 1);

        switch (pass[i].scale_type_x)
        {
        case GLSL_ABSOLUTE:
            pass[i].width = pass[i].scale_x;
            break;
        case GLSL_SOURCE:
            pass[i].width = pass[i-1].width * pass[i].scale_x;
            break;
        case GLSL_VIEWPORT:
            pass[i].width = viewport_width * pass[i].scale_x;
            break;
        default:
            pass[i].width = viewport_width;
        }

        switch (pass[i].scale_type_y)
        {
        case GLSL_ABSOLUTE:
            pass[i].height = pass[i].scale_y;
            break;
        case GLSL_SOURCE:
            pass[i].height = pass[i - 1].height * pass[i].scale_y;
            break;
        case GLSL_VIEWPORT:
            pass[i].height = viewport_height * pass[i].scale_y;
            break;
        default:
            pass[i].height = viewport_height;
        }

        /* set size of output texture
     */
        glBindTexture(GL_TEXTURE_2D, pass[i].texture);

        if (pass[i].srgb)
        {
            glEnable(GL_FRAMEBUFFER_SRGB);

            glTexImage2D(GL_TEXTURE_2D,
                         0,
                         GL_SRGB8_ALPHA8,
                         (unsigned int) pass[i].width,
                         (unsigned int) pass[i].height,
                         0,
                         GL_RGBA,
                         GL_UNSIGNED_INT_8_8_8_8,
                         NULL);
        }
        else
        {
            glTexImage2D(GL_TEXTURE_2D,
                         0,
                         (pass[i].fp ? GL_RGBA32F : GL_RGBA),
                         (unsigned int) pass[i].width,
                         (unsigned int) pass[i].height,
                         0,
                         GL_RGBA,
                         (pass[i].fp ? GL_FLOAT : GL_UNSIGNED_INT_8_8_8_8),
                          NULL);
        }

        // viewport determines the area we render into the output texture
        glViewport(0, 0, pass[i].width, pass[i].height);

        // set up framebuffer and attach output texture

        glBindFramebuffer(GL_FRAMEBUFFER, pass[i].fbo);
        glFramebufferTexture2D(GL_FRAMEBUFFER,
                               GL_COLOR_ATTACHMENT0,
                               GL_TEXTURE_2D,
                               pass[i].texture,
                               0);

        // set up input texture (output of previous pass) and apply filter settings

        GLuint filter = (pass[i].filter == GLSL_UNDEFINED) ?
                         (lastpass ?
                          (gui_config->bilinear_filter ? GL_LINEAR : GL_NEAREST) : GL_NEAREST
                              ) : pass[i].filter;

        glBindTexture(GL_TEXTURE_2D, pass[i - 1].texture);
        glPixelStorei(GL_UNPACK_ROW_LENGTH, (GLint) pass[i - 1].width);
        glTexParameteri(GL_TEXTURE_2D,
                        GL_TEXTURE_MAG_FILTER,
                        filter);
        glTexParameteri(GL_TEXTURE_2D,
                        GL_TEXTURE_MIN_FILTER,
                        filter);

        glTexCoordPointer(2, GL_FLOAT, 0, tex_coords);

        glUseProgram (pass[i].program);
        set_shader_vars(i);

        glClearColor(0.0f, 0.0f, 0.0f, 0.5f);
        glClear(GL_COLOR_BUFFER_BIT);
        glDrawArrays(GL_QUADS, 0, 4);

        /* reset client states enabled during setShaderVars
     */
        clear_shader_vars();

        if (pass[i].srgb)
        {
            glDisable (GL_FRAMEBUFFER_SRGB);
        }
    }

    /* disable framebuffer
   */
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
    glActiveTexture(GL_TEXTURE0);
    glUseProgram (0);

    /* set last PREV texture as original, push current texture and
         sizes to the front of the PREV deque and make sure the new
         original texture has the same size as the old one
      */

    if (prev_frame.size() > 0)
    {
        GLint internal_format;
        orig = prev_frame.back().texture;
        prev_frame.pop_back();

        GLSLPass newprevframe;
        newprevframe.width = width;
        newprevframe.height = height;
        newprevframe.texture = pass[0].texture;
        prev_frame.push_front(newprevframe);
        glBindTexture(GL_TEXTURE_2D, newprevframe.texture);
        glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_INTERNAL_FORMAT, &internal_format);

        glBindTexture(GL_TEXTURE_2D, orig);
        glPixelStorei(GL_UNPACK_ROW_LENGTH, width);
        glTexImage2D(GL_TEXTURE_2D,
                     0,
                     internal_format,
                     width,
                     height,
                     0,
                     GL_RGB,
                     GL_UNSIGNED_BYTE,
                     NULL);
    }

    glBindTexture(GL_TEXTURE_2D, pass.back().texture);
    glTexParameteri(GL_TEXTURE_2D,
                    GL_TEXTURE_MAG_FILTER,
                    pass.back().filter == GLSL_UNDEFINED ? (gui_config->bilinear_filter ? GL_LINEAR : GL_NEAREST) : pass.back().filter);
    glTexParameteri(GL_TEXTURE_2D,
                    GL_TEXTURE_MIN_FILTER,
                    pass.back().filter == GLSL_UNDEFINED ? (gui_config->bilinear_filter ? GL_LINEAR : GL_NEAREST) : pass.back().filter);

    glPixelStorei(GL_UNPACK_ROW_LENGTH, (GLint)pass.back().width);
    glTexCoordPointer(2, GL_FLOAT, 0, inv_coords);
}

void GLSLShader::register_uniforms ()
{
    max_prev_frame = 0;
    char varname[100];

    for (unsigned int i = 1; i < pass.size(); i++)
    {
        GLSLUniforms *u = &pass[i].unif;
        GLuint program = pass[i].program;

        glUseProgram (program);

        GLint mvp = glGetUniformLocation (program, "MVPMatrix");
        if (mvp > -1)
            glUniformMatrix4fv(mvp, 1, GL_FALSE, mvp_ortho);

        u->Texture = glGetUniformLocation (program, "Texture");
        u->InputSize = glGetUniformLocation (program, "InputSize");
        u->OutputSize = glGetUniformLocation (program, "OutputSize");
        u->TextureSize = glGetUniformLocation (program, "TextureSize");

        u->TexCoord = glGetAttribLocation (program, "TexCoord");
        u->LUTTexCoord = glGetAttribLocation (program, "LUTTexCoord");
        u->VertexCoord = glGetAttribLocation (program, "VertexCoord");

        u->FrameCount = glGetUniformLocation (program, "FrameCount");
        u->FrameDirection = glGetUniformLocation (program, "FrameDirection");

        u->OrigTexture = glGetUniformLocation (program, "OrigTexture");
        u->OrigInputSize = glGetUniformLocation (program, "OrigInputSize");
        u->OrigTextureSize = glGetUniformLocation (program, "OrigTextureSize");
        u->OrigTexCoord = glGetAttribLocation (program, "OrigTexCoord");

        u->Prev[0].Texture = glGetUniformLocation (program, "PrevTexture");
        u->Prev[0].InputSize = glGetUniformLocation (program, "PrevInputSize");
        u->Prev[0].TextureSize = glGetUniformLocation (program, "PrevTextureSize");
        u->Prev[0].TexCoord = glGetAttribLocation (program, "PrevTexCoord");

        if (u->Prev[0].Texture > -1)
            max_prev_frame = 1;

        for (unsigned int j = 1; j < 7; j++)
        {
            sprintf(varname, "Prev%dTexture", j);
            u->Prev[j].Texture = glGetUniformLocation (program, varname);
            sprintf(varname, "Prev%dInputSize", j);
            u->Prev[j].InputSize = glGetUniformLocation (program, varname);
            sprintf(varname, "Prev%dTextureSize", j);
            u->Prev[j].TextureSize = glGetUniformLocation (program, varname);
            sprintf(varname, "Prev%dTexCoord", j);
            u->Prev[j].TexCoord = glGetAttribLocation (program, varname);

            if (u->Prev[j].Texture > -1)
                max_prev_frame = j + 1;
        }
        for (unsigned int j = 0; j < pass.size(); j++)
        {
            sprintf(varname, "Pass%dTexture", j);
            u->Pass[j].Texture = glGetUniformLocation (program, varname);
            sprintf(varname, "Pass%dInputSize", j);
            u->Pass[j].InputSize = glGetUniformLocation (program, varname);
            sprintf(varname, "Pass%dTextureSize", j);
            u->Pass[j].TextureSize = glGetUniformLocation (program, varname);
            sprintf(varname, "Pass%dTexCoord", j);
            u->Pass[j].TexCoord = glGetAttribLocation (program, varname);
            if (u->Pass[j].Texture)
                u->max_pass = j;

            sprintf(varname, "PassPrev%dTexture", j);
            u->PassPrev[j].Texture = glGetUniformLocation (program, varname);
            sprintf(varname, "PassPrev%dInputSize", j);
            u->PassPrev[j].InputSize = glGetUniformLocation (program, varname);
            sprintf(varname, "PassPrev%dTextureSize", j);
            u->PassPrev[j].TextureSize = glGetUniformLocation (program, varname);
            sprintf(varname, "PassPrev%dTexCoord", j);
            u->PassPrev[j].TexCoord = glGetAttribLocation (program, varname);
            if (u->PassPrev[j].Texture > -1)
                u->max_prevpass = j;
        }

        for (unsigned int j = 0; j < lut.size(); j++)
        {
            u->Lut[j] = glGetUniformLocation (program, lut[j].id);
        }

        for (unsigned int j = 0; j < param.size(); j++)
        {
            param[j].unif[i] = glGetUniformLocation (program, param[j].id);
        }
    }

    glUseProgram (0);
}

void GLSLShader::set_shader_vars (int p)
{
    unsigned int texunit = 0;
    GLSLUniforms *u = &pass[p].unif;

    GLint mvp = glGetUniformLocation (pass[p].program, "MVPMatrix");
    if (mvp > -1)
        glUniformMatrix4fv(mvp, 1, GL_FALSE, mvp_ortho);

#define setUniform2fv(uni, val) if (uni > -1) glUniform2fv (uni, 1, val);
#define setUniform1f(uni, val) if (uni > -1) glUniform1f (uni, val);
#define setUniform1i(uni, val) if (uni > -1) glUniform1i (uni, val);
#define setTexture1i(uni, val) \
    if (uni > -1) \
    { \
        glActiveTexture (GL_TEXTURE0 + texunit); \
        glBindTexture (GL_TEXTURE_2D, val); \
        glUniform1i (uni, texunit); \
        texunit++; \
    }
    /* We use non-power-of-two textures,
     * so no need to mess with input size/texture size */
#define setTexCoords(attr) \
    if (attr > -1) \
    { \
        glEnableVertexAttribArray(attr); \
        glVertexAttribPointer(attr, 2, GL_FLOAT, GL_FALSE, 0, NULL); \
        vaos.push_back (attr); \
    }

    glBindBuffer (GL_ARRAY_BUFFER, vbo);
    glBufferData (GL_ARRAY_BUFFER, sizeof (GLfloat) * 8, tex_coords, GL_STATIC_DRAW);

    float inputSize[2] = { (float) pass[p - 1].width, (float) pass[p - 1].height };
    float outputSize[2] = { (float) pass[p].width, (float) pass[p].height };

    setTexture1i (u->Texture, pass[p - 1].texture);
    setUniform2fv(u->InputSize, inputSize);
    setUniform2fv(u->OutputSize, outputSize);
    setUniform2fv(u->TextureSize, inputSize);

    unsigned int shaderFrameCnt = frame_count;
    if (pass[p].frame_count_mod)
        shaderFrameCnt %= pass[p].frame_count_mod;
    setUniform1i(u->FrameCount, (float) shaderFrameCnt);
    setUniform1i(u->FrameDirection, top_level->user_rewind ? -1.0f : 1.0f);

    setTexCoords (u->TexCoord);
    setTexCoords (u->LUTTexCoord);
    setTexCoords (u->VertexCoord);
    /* ORIG parameter
       */
    float orig_videoSize[2] = { (float) pass[0].width, (float) pass[0].height };

    setUniform2fv(u->OrigInputSize,  orig_videoSize);
    setUniform2fv(u->OrigTextureSize, orig_videoSize);
    setTexture1i (u->OrigTexture, pass[0].texture);
    setTexCoords (u->OrigTexCoord);

    /* PREV parameter
       */
    if (max_prev_frame >= 1 && prev_frame[0].width > 0) {
        float prevSize[2] = { (float) prev_frame[0].width, (float) prev_frame[0].height };

        setUniform2fv(u->Prev[0].InputSize, prevSize);
        setUniform2fv(u->Prev[0].TextureSize, prevSize);
        setTexture1i (u->Prev[0].Texture, prev_frame[0].texture);
        setTexCoords (u->Prev[0].TexCoord);
    }

    /* PREV1-6 parameters
       */
    for (unsigned int i = 1; i < prev_frame.size(); i++)
    {
        if (prev_frame[i].width <= 0)
            break;

        float prevSize[2] = { (float) prev_frame[i].width, (float) prev_frame[i].height };

        setUniform2fv(u->Prev[i].InputSize, prevSize);
        setUniform2fv(u->Prev[i].TextureSize, prevSize);
        setTexture1i (u->Prev[i].Texture, prev_frame[i].texture);
        setTexCoords (u->Prev[i].TexCoord);
    }

    /* LUT parameters
       */
    for (unsigned int i = 0; i < lut.size(); i++)
    {
        setTexture1i (u->Lut[i], lut[i].texture);
    }

    /* PASSX parameters, only for third pass and up
       */
    if (p > 2) {
        for (int i = 1; i < p - 1; i++) {
            float passSize[2] = { (float) pass[i].width, (float) pass[i].height };
            setUniform2fv(u->Pass[i].InputSize, passSize);
            setUniform2fv(u->Pass[i].TextureSize, passSize);
            setTexture1i (u->Pass[i].Texture, pass[i].texture);
            setTexCoords (u->Pass[i].TexCoord);
        }
    }

    /* PASSPREV parameter */
    for (int i = 0; i < p; i++)
    {
        float passSize[2] = { (float) pass[i].width, (float) pass[i].height };
        setUniform2fv(u->PassPrev[p - i].InputSize, passSize);
        setUniform2fv(u->PassPrev[p - i].TextureSize, passSize);
        setTexture1i (u->PassPrev[p - i].Texture, pass[i].texture);
        setTexCoords (u->PassPrev[p - i].TexCoord);
    }

    /* Parameters */
    for (unsigned int i = 0; i < param.size(); i++)
    {
        setUniform1f (param[i].unif[p], param[i].val);
    }

    glActiveTexture (GL_TEXTURE0);
    glBindBuffer (GL_ARRAY_BUFFER, 0);
}

void GLSLShader::clear_shader_vars (void)
{
    for (unsigned int i = 0; i < vaos.size(); i++)
        glDisableVertexAttribArray (vaos[i]);

    vaos.clear();
}

#define outs(s, v) fprintf (file, "%s%d = \"%s\"\n", s, i, v)
#define outf(s, v) fprintf (file, "%s%d = \"%f\"\n", s, i, v)
#define outd(s, v) fprintf (file, "%s%d = \"%d\"\n", s, i, v)
void GLSLShader::save (void)
{
    char *config_dir = get_config_dir();
    char *config_file = new char[strlen (config_dir) + 14];
    sprintf(config_file, "%s/shader.glslp", config_dir);
    delete[] config_dir;

    FILE *file = fopen (config_file, "wb");
    if (!file)
    {
        printf ("Couldn't save shader config to %s\n", config_file);
    }

    fprintf (file, "shaders = \"%d\"\n", (unsigned int) pass.size() - 1);

    for (unsigned int pn = 1; pn < pass.size(); pn++)
    {
        GLSLPass *p = &pass[pn];
        unsigned int i = pn - 1;

        outs("shader", p->filename);
        if (p->filter != GLSL_UNDEFINED)
        {
            outs("filter_linear", p->filter == GL_LINEAR ? "true" : "false");
        }
        //outs ("wrap_mode", wrap_mode_enum_to_string(p->wrap_mode));
        //outs ("alias", p->alias);
        outs ("float_framebuffer", p->fp ? "true" : "false");
        outs ("srgb_framebuffer", p->srgb ? "true" : "false");
        outs ("scale_type_x", scale_enum_to_string(p->scale_type_x));
        if (p->scale_type_x == GLSL_ABSOLUTE)
            outd ("scale_x", (int) p->scale_x);
        else
            outf ("scale_x", p->scale_x);

        outs ("scale_type_y", scale_enum_to_string(p->scale_type_y));
        if (p->scale_type_y == GLSL_ABSOLUTE)
            outd ("scale_y", (int) p->scale_y);
        else
            outf ("scale_y", p->scale_y);

        if (p->frame_count_mod)
            outd ("frame_count_mod", p->frame_count_mod);
    }

    if (param.size() > 0)
    {
        fprintf (file, "parameters = \"");
        for (unsigned int i = 0; i < param.size(); i++)
        {
            fprintf (file, "%s%c", param[i].id, (i == param.size() - 1) ? '\"' : ';');
        }
        fprintf (file, "\n");
    }

    for (unsigned int i = 0; i < param.size(); i++)
    {
        fprintf (file, "%s = \"%f\"\n", param[i].id, param[i].val);
    }

    if (lut.size() > 0)
    {
        fprintf (file, "textures = \"");
        for (unsigned int i = 0; i < lut.size(); i++)
        {
            fprintf (file, "%s%c", lut[i].id, (i == lut.size() - 1) ? '\"' : ';');
        }
        fprintf (file, "\n");
    }

    for (unsigned int i = 0; i < lut.size(); i++)
    {
        fprintf (file, "%s = \"%s\"\n", lut[i].id, lut[i].filename);
        fprintf (file, "%s_linear = \"%s\"\n", lut[i].id, lut[i].filter == GL_LINEAR || lut[i].filter == GL_LINEAR_MIPMAP_LINEAR ? "true" : "false");
        fprintf (file, "%s_wrap_mode = \"%s\"\n", lut[i].id, wrap_mode_enum_to_string(lut[i].wrap_mode));
        fprintf (file, "%s_mipmap = \"%s\"\n", lut[i].id, lut[i].mipmap ? "true" : "false");
    }

    fclose (file);

    realpath (config_file, gui_config->fragment_shader);
    delete[] config_file;
}
#undef outf
#undef outs
#undef outd


void GLSLShader::destroy (void)
{
    glBindTexture(GL_TEXTURE_2D, 0);
    glUseProgram(0);
    glActiveTexture(GL_TEXTURE0);

    for (unsigned int i = 1; i < pass.size(); i++)
    {
        glDeleteProgram(pass[i].program);
        glDeleteTextures(1, &pass[i].texture);
        glDeleteFramebuffers(1, &pass[i].fbo);
    }

    for (unsigned int i = 0; i < lut.size(); i++)
    {
        glDeleteTextures (1, &lut[i].texture);
    }

    for (unsigned int i = 0; i < prev_frame.size (); i++)
    {
        glDeleteTextures (1, &prev_frame[i].texture);
    }

    param.clear();
    pass.clear();
    lut.clear();
    prev_frame.clear();
}