r_program.cpp

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/*
* Copyright(c) 1997-2001 Id Software, Inc.
* Copyright(c) 2002 The Quakeforge Project.
* Copyright(c) 2006 Quake2World.
*
* 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 2
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

#include "r_local.h"
#include "r_error.h"
#include "r_program.h"
#include "../../shared/parse.h"
#include "../../shared/shared.h"

#define SHADER_BUF_SIZE 16384

typedef enum {SHQ_LOW, SHQ_MID, SHQ_HIGH, SHQ_NUM} shaderQualityLevel_t;

const char* shaderQualityLevelNames[SHQ_NUM][2] = {
    {"world_low","model_low"},
    {"world_med","model_med"},
    {"world_med","model_high"} 
};

void R_UseProgram  (r_program_t* prog)
{
    if (!qglUseProgram || r_state.active_program == prog)
        return;

    if (!r_state.active_program)
        refdef.FFPToShaderCount++;
    else if (!prog)
        refdef.shaderToFFPCount++;
    else
        refdef.shaderToShaderCount++;

    r_state.active_program = prog;

    if (prog) {
        qglUseProgram(prog->id);

        if (prog->use)  /* invoke use function */
            prog->use(prog);
    } else {
        qglUseProgram(0);
    }
}

static r_progvar_t* R_ProgramVariable (int type, const char* name)
{
    r_progvar_t* v;
    int i;

    if (!r_state.active_program) {
        Com_DPrintf(DEBUG_RENDERER, "R_ProgramVariable: \"%s\" - No program bound.\n", name);
        return nullptr;
    }

    /* find the variable */
    for (i = 0; i < MAX_PROGRAM_VARS; i++) {
        v = &r_state.active_program->vars[i];

        if (!v->location)
            break;

        if (v->type == type && Q_streq(v->name, name))
            return v;
    }

    if (i == MAX_PROGRAM_VARS) {
        Com_Printf("R_ProgramVariable: MAX_PROGRAM_VARS reached.\n");
        return nullptr;
    }

    /* or query for it */
    if (type == GL_UNIFORM)
        v->location = qglGetUniformLocation(r_state.active_program->id, name);
    else
        v->location = qglGetAttribLocation(r_state.active_program->id, name);

    if (v->location == -1) {
        Com_Printf("R_ProgramVariable: Could not find parameter %s in program %s.\n", name, r_state.active_program->name);
        v->location = 0;
        return nullptr;
    }

    v->type = type;
    Q_strncpyz(v->name, name, sizeof(v->name));

    return v;
}

void R_ProgramParameter1i (const char* name, GLint value)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_UNIFORM, name)))
        return;

    qglUniform1i(v->location, value);
}

void R_ProgramParameter1f (const char* name, GLfloat value)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_UNIFORM, name)))
        return;

    qglUniform1f(v->location, value);
}

void R_ProgramParameter1fvs (const char* name, GLint size, GLfloat* value)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_UNIFORM, name)))
        return;

    qglUniform1fv(v->location, size, value);
}

void R_ProgramParameter2fv (const char* name, GLfloat* value)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_UNIFORM, name)))
        return;

    qglUniform2fv(v->location, 1, value);
}

void R_ProgramParameter2fvs (const char* name, GLint size, GLfloat* value)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_UNIFORM, name)))
        return;

    qglUniform2fv(v->location, size, value);
}

void R_ProgramParameter3fv (const char* name, GLfloat* value)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_UNIFORM, name)))
        return;

    qglUniform3fv(v->location, 1, value);
}

void R_ProgramParameter3fvs (const char* name, GLint size, GLfloat* value)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_UNIFORM, name)))
        return;

    qglUniform3fv(v->location, size, value);
}

void R_ProgramParameter4fv (const char* name, GLfloat* value)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_UNIFORM, name)))
        return;

    qglUniform4fv(v->location, 1, value);
}

void R_ProgramParameter4fvs (const char* name, GLint size, GLfloat* value)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_UNIFORM, name)))
        return;

    qglUniform4fv(v->location, size, value);
}

void R_ProgramParameterMatrix4fv (const char* name, GLfloat* value)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_UNIFORM, name)))
        return;

    qglUniformMatrix4fv(v->location, 1, GL_FALSE, value);
}

void R_AttributePointer (const char* name, GLuint size, const GLvoid* array)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_ATTRIBUTE, name)))
        return;

    qglVertexAttribPointer(v->location, size, GL_FLOAT, GL_FALSE, 0, array);
}

void R_EnableAttribute (const char* name)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_ATTRIBUTE, name)))
        return;

    qglEnableVertexAttribArray(v->location);
}

void R_DisableAttribute (const char* name)
{
    r_progvar_t* v;

    if (!(v = R_ProgramVariable(GL_ATTRIBUTE, name)))
        return;

    qglDisableVertexAttribArray(v->location);
}

static void R_ShutdownShader (r_shader_t* sh)
{
    qglDeleteShader(sh->id);
    OBJZERO(*sh);
}

static void R_ShutdownProgram (r_program_t* prog)
{
    if (prog->v) {
        qglDetachShader(prog->id, prog->v->id);
        R_ShutdownShader(prog->v);
        R_CheckError();
    }
    if (prog->f) {
        qglDetachShader(prog->id, prog->f->id);
        R_ShutdownShader(prog->f);
        R_CheckError();
    }

    qglDeleteProgram(prog->id);

    OBJZERO(*prog);
}

void R_ShutdownPrograms (void)
{
    if (!qglDeleteProgram)
        return;

    if (!r_programs->integer)
        return;

    for (int i = 0; i < MAX_PROGRAMS; i++) {
        if (!r_state.programs[i].id)
            continue;

        R_ShutdownProgram(&r_state.programs[i]);
    }
}

static size_t R_PreprocessShaderAddToShaderBuf (const char* name, const char* in, char** out, size_t* len)
{
    const size_t inLength = strlen(in);
    strcpy(*out, in);
    *out += inLength;
    *len -= inLength;
    return inLength;
}

static size_t R_InitializeShader (const GLenum type, const char* name, char* out, size_t len)
{
    size_t initialChars = 0;
    const char* hwHack, *defines;
    /* in the format GLSL compiler expects it -- e.g. 110 for version 1.10 */
    const int shaderVersion = (int)(r_glsl_version->value * 100 + 0.1);

    switch (r_config.hardwareType) {
    case GLHW_ATI:
        hwHack = "#ifndef ATI\n#define ATI\n#endif\n";
        break;
    case GLHW_INTEL:
        hwHack = "#ifndef INTEL\n#define INTEL\n#endif\n";
        break;
    case GLHW_NVIDIA:
        hwHack = "#ifndef NVIDIA\n#define NVIDIA\n#endif\n";
        break;
    case GLHW_MESA:
        hwHack = "#ifndef MESA\n#define MESA\n#endif\n";
        break;
    case GLHW_GENERIC:
        hwHack = nullptr;
        break;
    default:
        Com_Error(ERR_FATAL, "R_PreprocessShader: Unknown hardwaretype");
    }

    /*
     * Prefix "#version xxx" onto shader string.
     * This causes GLSL compiler to compile to that version.
     */
    defines = va("#version %d\n", shaderVersion);
    initialChars += R_PreprocessShaderAddToShaderBuf(name, defines, &out, &len);

    /*
     * Prefix "#define glslxxx" onto shader string.
     * This named constant is used to setup shader code to match the desired GLSL spec.
     */
    defines = va("#define glsl%d\n", shaderVersion);
    initialChars += R_PreprocessShaderAddToShaderBuf(name, defines, &out, &len);

    /* Define r_width.*/
    defines = va("#ifndef r_width\n#define r_width %f\n#endif\n", (float)viddef.context.width);
    initialChars += R_PreprocessShaderAddToShaderBuf(name, defines, &out, &len);

    /* Define r_height.*/
    defines = va("#ifndef r_height\n#define r_height %f\n#endif\n", (float)viddef.context.height);
    initialChars += R_PreprocessShaderAddToShaderBuf(name, defines, &out, &len);

    if (hwHack) {
        initialChars += R_PreprocessShaderAddToShaderBuf(name, hwHack, &out, &len);
    }

    if (GL_VERTEX_SHADER == type) {
        /* Define 'in_qualifier as 'attribute' & 'out_qualifier' as 'varying' if GLSL v1.10, otherwise define them as 'in' and 'out' respectively.*/
        initialChars += R_PreprocessShaderAddToShaderBuf(name, "#ifndef glsl110\n#define in_qualifier in\n#define out_qualifier out\n#else\n#define in_qualifier attribute\n#define out_qualifier varying\n#endif\n", &out, &len);
    } else if (GL_FRAGMENT_SHADER == type) {
        /* Define 'texture2D' as 'texture', as texture2D was deprecated (replaced with 'texture') as of GLSL v1.30.*/
        initialChars += R_PreprocessShaderAddToShaderBuf(name, "#ifndef glsl110\n#define texture2D texture\n#endif\n", &out, &len);
        /* Define 'in_qualifier as 'varying' if GLSL v1.10, otherwise define it as 'in'.*/
        initialChars += R_PreprocessShaderAddToShaderBuf(name, "#ifndef glsl110\n#define in_qualifier in\n#else\n#define in_qualifier varying\n#endif\n", &out, &len);
    }

    return initialChars;
}

static size_t R_PreprocessShaderR (const char* name, const char** inPtr, char* out, long* remainingOutChars, bool nested, bool inElse)
{
    const size_t INITIAL_REMAINING_OUT_CHARS = (size_t)*remainingOutChars;
    /* Keep looping till we reach the end of the shader string, or a parsing error.*/
    while (**inPtr) {
        if ('#' == **inPtr) {
            bool endBlockToken;
            (*inPtr)++;

            endBlockToken = !strncmp(*inPtr, "endif", 5);

            if (!strncmp(*inPtr, "else", 4)) {
                if (inElse) {
                    /* Error in shader! Print a message saying our preprocessor failed parsing.*/
                    Com_Error(ERR_DROP, "R_PreprocessShaderR: #else without #if: %s", name);
                }
                endBlockToken = true;
            }

            if (endBlockToken) {
                if (!nested) {
                    /* Error in shader! Print a message saying our preprocessor failed parsing.*/
                    Com_Error(ERR_DROP, "R_PreprocessShaderR: Unmatched #endif/#else: %s", name);
                }
                /* Whoever called us will have to deal with closing the block */
                return (INITIAL_REMAINING_OUT_CHARS - (size_t)*remainingOutChars);
            }

            if (!strncmp((*inPtr), "if ", 3)) {
                /* The line looks like "#if r_postprocess".*/
                (*inPtr) += 3;
                /* Get the corresponding cvar value.*/
                float f = Cvar_GetValue(Com_Parse(inPtr));
                if (f) { /* Condition is true, recursively preprocess #if block, and skip over #else block, if any */
                    int size = R_PreprocessShaderR(name, inPtr, out, remainingOutChars, true, false);
                    if (out) out += size;

                    if (!strncmp((*inPtr), "else", 4)) {/* Preprocess and skip #else block */
                        (*inPtr) +=4 ;
                        R_PreprocessShaderR(name, inPtr, (char*)0, remainingOutChars, true, true);
                    }
                } else {
                    /* The cvar was false, don't add to out. Lets look and see if we hit a #else, or #endif.*/
                    R_PreprocessShaderR(name, inPtr, (char*)0, remainingOutChars, true, false);
                    if (!strncmp((*inPtr), "else", 4)) {
                        int size;
                        /* All right, we want to add this to out.*/
                        (*inPtr) +=4 ;
                        size = R_PreprocessShaderR(name, inPtr, out, remainingOutChars, true, true);
                        if (out) out += size;
                    }
                }
                /* skip #endif, if any (could also get here by unexpected EOF */
                if (!strncmp((*inPtr), "endif", 5))
                    (*inPtr) +=5 ;
            } else if (!strncmp((*inPtr), "ifndef", 6) || !strncmp((*inPtr), "ifdef", 5)) { /* leave those for GLSL compiler, but follow #else/#endif nesting */
                int size;
                if (out) {
                    if (*remainingOutChars <= 0)
                        Com_Error(ERR_FATAL, "R_PreprocessShaderR: Overflow in shader loading '%s'", name);
                    *out++ = '#';
                    (*remainingOutChars)--;
                }

                size = R_PreprocessShaderR(name, inPtr, out, remainingOutChars, true, false);
                if (out) out += size;

                if (!strncmp((*inPtr), "else", 4)) {
                    if (out) {
                        if (*remainingOutChars <= 0)
                            Com_Error(ERR_FATAL, "R_PreprocessShaderR: Overflow in shader loading '%s'", name);
                        *out++ = '#';
                        (*remainingOutChars)--;
                    }
                    size = R_PreprocessShaderR(name, inPtr, out, remainingOutChars, true, true);
                    if (out) out += size;
                }

                if (out) {
                    if (*remainingOutChars <= 0)
                        Com_Error(ERR_FATAL, "R_PreprocessShaderR: Overflow in shader loading '%s'", name);
                    *out++ = '#';
                    (*remainingOutChars)--;
                }

            } else if (!strncmp((*inPtr), "include", 7)) {
                char path[MAX_QPATH];
                byte* buf = (byte*)0;
                const char* bufAsChar = (const char*)0;
                const char** bufAsCharPtr = (const char**)0;
                (*inPtr) += 8;
                Com_sprintf(path, sizeof(path), "shaders/%s", Com_Parse(inPtr));
                if (FS_LoadFile(path, &buf) == -1) {
                    Com_Printf("Failed to resolve #include: %s.\n", path);
                    continue;
                }
                bufAsChar = (const char*)buf;
                bufAsCharPtr = &bufAsChar;
                if (out) {
                    out += R_PreprocessShaderR(name, bufAsCharPtr, out, remainingOutChars, nested, false);
                } else {
                    R_PreprocessShaderR(name, bufAsCharPtr, out, remainingOutChars, nested, false);
                }
                FS_FreeFile(buf);
            } else if (!strncmp((*inPtr), "unroll", 6)) {
                /* loop unrolling */
                size_t subLength = 0;
                byte* const buffer = Mem_PoolAllocTypeN(byte, SHADER_BUF_SIZE, vid_imagePool);
                (*inPtr) += 6;
                int z = Cvar_GetValue(Com_Parse(inPtr));
                while (*(*inPtr)) {
                    if (!strncmp((*inPtr), "#endunroll", 10)) {
                        (*inPtr) += 10;
                        break;
                    }
                    buffer[subLength++] = *(*inPtr)++;
                    if (subLength >= SHADER_BUF_SIZE)
                        Com_Error(ERR_FATAL, "R_PreprocessShaderR: Overflow in shader loading '%s'", name);
                }
                if (out) {
                    for (int j = 0; j < z; j++) {
                        for (int l = 0; l < subLength; l++) {
                            if (buffer[l] == '$') {
                                byte insertedLen = (j / 10) + 1;
                                if (!Com_sprintf(out, (size_t)*remainingOutChars, "%d", j))
                                    Com_Error(ERR_FATAL, "R_PreprocessShaderR: Overflow in shader loading '%s'", name);
                                out += insertedLen;
                                (*remainingOutChars) -= insertedLen;
                            } else {
                                if (*remainingOutChars <= 0)
                                    Com_Error(ERR_FATAL, "R_PreprocessShaderR: Overflow in shader loading '%s'", name);
                                *out++ = buffer[l];
                                (*remainingOutChars)--;
                            }
                        }
                    }
                }
                Mem_Free(buffer);
            } else if (!strncmp((*inPtr), "replace", 7)) {
                int r = 0;
                (*inPtr) += 8;
                r = Cvar_GetValue(Com_Parse(inPtr));
                if (out) {
                    byte insertedLen = 0;
                    if (!Com_sprintf(out, (size_t)*remainingOutChars, "%d", r))
                        Com_Error(ERR_FATAL, "R_PreprocessShaderR: Overflow in shader loading '%s'", name);
                    insertedLen = (r / 10) + 1;
                    out += insertedLen;
                    (*remainingOutChars) -= insertedLen;
                }
            } else {
                /* general case is to copy so long as the buffer has room */
                if (out) {
                    if (*remainingOutChars <= 0)
                        Com_Error(ERR_FATAL, "R_PreprocessShaderR: Overflow in shader loading '%s'", name);
                    *out++ = '#';
                    (*remainingOutChars)--;
                }
            }
        } else {
            /* general case is to copy so long as the buffer has room */
            if (out) {
                if (*remainingOutChars <= 0)
                    Com_Error(ERR_FATAL, "R_PreprocessShaderR: Overflow in shader loading '%s'", name);
                *out++ = *(*inPtr);
                (*remainingOutChars)--;
            }
            (*inPtr)++;
        }
    }
    /* Return the number of characters added to the buffer.*/
    return (INITIAL_REMAINING_OUT_CHARS - *remainingOutChars);
}

static size_t R_PreprocessShader (const char* name, const char* in, char* out, size_t* remainingOutChars)
{
    long remainingOutCharsAsLong = *remainingOutChars;
    size_t numCharactersAddedToOutBuffer = R_PreprocessShaderR(name, &in, out, &remainingOutCharsAsLong, false, false);
    *remainingOutChars = remainingOutCharsAsLong;
    return numCharactersAddedToOutBuffer;
}

static r_shader_t* R_LoadShader (const GLenum type, const char* name)
{
    r_shader_t* sh;
    char path[MAX_QPATH], *src[1];
    unsigned e, length[1];
    char* srcBuf;
    byte* buf;
    int i;
    size_t bufLength = SHADER_BUF_SIZE;
    size_t initializeLength;

#ifdef DEBUG
    /* Used to contain result of shader compile.*/
    char log[MAX_STRING_CHARS];
#endif

    snprintf(path, sizeof(path), "shaders/%s", name);

    if (FS_LoadFile(path, &buf) == -1) {
        Com_DPrintf(DEBUG_RENDERER, "R_LoadShader: Failed to load ./base/shaders/%s.\n", name);
        return nullptr;
    }

    Com_DPrintf(DEBUG_RENDERER, "R_LoadShader: Loading ./base/shaders/%s.\n", name);

    char* const source = srcBuf = Mem_PoolAllocTypeN(char, bufLength, vid_imagePool);

    initializeLength = R_InitializeShader(type, name, srcBuf, bufLength);
    srcBuf += initializeLength;
    bufLength -= initializeLength;

    R_PreprocessShader(name, (const char*)buf, srcBuf, &bufLength);
    FS_FreeFile(buf);

    src[0] = source;
    length[0] = strlen(source);

    for (i = 0; i < MAX_SHADERS; i++) {
        sh = &r_state.shaders[i];

        if (!sh->id)
            break;
    }

    if (i == MAX_SHADERS) {
        Com_Printf("R_LoadShader: MAX_SHADERS reached.\n");
        Mem_Free(source);
        return nullptr;
    }

    Q_strncpyz(sh->name, name, sizeof(sh->name));

    sh->type = type;

    sh->id = qglCreateShader(sh->type);
    if (!sh->id) {
        Mem_Free(source);
        return nullptr;
    }

    /* upload the shader source */
    qglShaderSource(sh->id, 1, src, length);

    /* compile it and check for errors */
    qglCompileShader(sh->id);

    Mem_Free(source);

    qglGetShaderiv(sh->id, GL_COMPILE_STATUS, &e);
#ifdef DEBUG
    qglGetShaderInfoLog(sh->id, sizeof(log) - 1, nullptr, log);
    Com_Printf("R_LoadShader: %s: %s", sh->name, log);
#endif
    if (!e) {
#ifndef DEBUG
        char log[MAX_STRING_CHARS];
        qglGetShaderInfoLog(sh->id, sizeof(log) - 1, nullptr, log);
        Com_Printf("R_LoadShader: %s: %s", sh->name, log);
#endif

        qglDeleteShader(sh->id);
        OBJZERO(*sh);

        return nullptr;
    }

    return sh;
}

r_program_t* R_LoadProgram (const char* name, programInitFunc_t init, programUseFunc_t use)
{
    r_program_t* prog;
    unsigned e;
    int i;

    /* shaders are deactivated */
    if (!r_programs->integer)
        return nullptr;

    /* search existing one */
    for (i = 0; i < MAX_PROGRAMS; i++) {
        prog = &r_state.programs[i];

        if (Q_streq(prog->name, name))
            return prog;
    }

    /* search free slot */
    for (i = 0; i < MAX_PROGRAMS; i++) {
        prog = &r_state.programs[i];

        if (!prog->id)
            break;
    }

    if (i == MAX_PROGRAMS) {
        Com_Printf("R_LoadProgram: MAX_PROGRAMS reached.\n");
        return nullptr;
    }

    Q_strncpyz(prog->name, name, sizeof(prog->name));

    prog->id = qglCreateProgram();

    prog->v = R_LoadShader(GL_VERTEX_SHADER, va("%s_vs.glsl", name));
    prog->f = R_LoadShader(GL_FRAGMENT_SHADER, va("%s_fs.glsl", name));

    if (prog->v)
        qglAttachShader(prog->id, prog->v->id);
    if (prog->f)
        qglAttachShader(prog->id, prog->f->id);

    qglLinkProgram(prog->id);

    qglGetProgramiv(prog->id, GL_LINK_STATUS, &e);
    if (!e || !prog->v || !prog->f) {
        char log[MAX_STRING_CHARS];
        qglGetProgramInfoLog(prog->id, sizeof(log) - 1, nullptr, log);
        Com_Printf("R_LoadProgram: %s: %s\n", prog->name, log);

        R_ShutdownProgram(prog);
        return nullptr;
    }

    prog->init = init;

    if (prog->init) {  /* invoke initialization function */
        R_UseProgram(prog);

        prog->init(prog);

        R_UseProgram(nullptr);
    }

    prog->use = use;

    Com_Printf("R_LoadProgram: '%s' loaded.\n", name);

    return prog;
}

extern vec2_t fogRange;

static void R_InitWorldProgram (r_program_t* prog)
{
    R_ProgramParameter1i("SAMPLER_DIFFUSE", 0);
    R_ProgramParameter1i("SAMPLER_LIGHTMAP", 1);
    R_ProgramParameter1i("SAMPLER_DELUXEMAP", 2);
    R_ProgramParameter1i("SAMPLER_NORMALMAP", 3);
    R_ProgramParameter1i("SAMPLER_GLOWMAP", 4);

    R_ProgramParameter1i("BUMPMAP", 0);

    if (r_programs->integer > 1) {
        R_ProgramParameter3fv("AMBIENT", refdef.ambientColor);

        R_ProgramParameter1i("SPECULARMAP", 0);
        R_ProgramParameter1i("SAMPLER_SPECULAR", 5);

        R_ProgramParameter1f("HARDNESS", defaultMaterial.hardness);
        R_ProgramParameter1f("SPECULAR", defaultMaterial.specular);
        R_ProgramParameter1f("PARALLAX", defaultMaterial.parallax);
    }

    R_ProgramParameter1f("BUMP", defaultMaterial.bump);
    R_ProgramParameter1f("GLOWSCALE", defaultMaterial.glowscale);

    if (r_fog->integer) {
        if (r_state.fog_enabled) {
            R_ProgramParameter3fv("FOGCOLOR", refdef.fogColor);
            R_ProgramParameter1f("FOGDENSITY", refdef.fogColor[3]);
            R_ProgramParameter2fv("FOGRANGE", fogRange);
        } else {
            R_ProgramParameter1f("FOGDENSITY", 0.0f);
        }
    }
}

static void R_UseWorldProgram (r_program_t* prog)
{
    if (r_programs->integer > 1) {
        R_ProgramParameter3fv("AMBIENT", refdef.ambientColor);
    }

    if (r_fog->integer) {
        if (r_state.fog_enabled) {
            R_ProgramParameter3fv("FOGCOLOR", refdef.fogColor);
            R_ProgramParameter1f("FOGDENSITY", refdef.fogColor[3]);
            R_ProgramParameter2fv("FOGRANGE", fogRange);
        } else {
            R_ProgramParameter1f("FOGDENSITY", 0.0f);
        }
    }
}

static void R_InitModelProgram (r_program_t* prog)
{
    vec4_t sunDirection;

    R_ProgramParameter1i("SAMPLER_DIFFUSE", 0);
    R_ProgramParameter1i("SAMPLER_NORMALMAP", 3);
    R_ProgramParameter1i("SAMPLER_GLOWMAP", 4);

    R_ProgramParameter1i("BUMPMAP", 0);
    R_ProgramParameter1i("ANIMATE", 0);

    R_ProgramParameter1f("BUMP", defaultMaterial.bump);
    R_ProgramParameter1f("GLOWSCALE", defaultMaterial.glowscale);
    R_ProgramParameter1f("OFFSET", 0.0);

    R_ProgramParameter3fv("AMBIENT", refdef.modelAmbientColor);
    R_ProgramParameter3fv("SUNCOLOR", refdef.sunDiffuseColor);

    GLVectorTransform(r_locals.world_matrix, refdef.sunVector, sunDirection);
    R_ProgramParameter3fv("SUNDIRECTION", sunDirection); /* last component is not needed */

    if (r_programs->integer > 1) {
        R_ProgramParameter1i("SAMPLER_SPECULAR", 5);
        R_ProgramParameter1i("SPECULARMAP", 0);
        R_ProgramParameter1f("HARDNESS", defaultMaterial.hardness);
        R_ProgramParameter1f("SPECULAR", defaultMaterial.specular);
        R_ProgramParameter1f("PARALLAX", defaultMaterial.parallax);
        if (r_programs->integer > 2) {
            R_ProgramParameter1i("SAMPLER_ROUGHMAP", 2);
            R_ProgramParameter1i("ROUGHMAP", 0);
        }
    }

    if (r_fog->integer) {
        if (r_state.fog_enabled) {
            R_ProgramParameter3fv("FOGCOLOR", refdef.fogColor);
            R_ProgramParameter1f("FOGDENSITY", refdef.fogColor[3]);
            R_ProgramParameter2fv("FOGRANGE", fogRange);
        } else {
            R_ProgramParameter1f("FOGDENSITY", 0.0f);
        }
    }
}

static void R_UseModelProgram (r_program_t* prog)
{
    vec4_t sunDirection;
    /*R_ProgramParameter1i("LIGHTS", refdef.numLights);*/

    R_ProgramParameter1f("OFFSET", 0.0);
    R_ProgramParameter3fv("AMBIENT", refdef.modelAmbientColor);
    R_ProgramParameter3fv("SUNCOLOR", refdef.sunDiffuseColor);

    GLVectorTransform(r_locals.world_matrix, refdef.sunVector, sunDirection);
    R_ProgramParameter3fv("SUNDIRECTION", sunDirection); /* last component is not needed */

    if (r_fog->integer) {
        if (r_state.fog_enabled) {
            R_ProgramParameter3fv("FOGCOLOR", refdef.fogColor);
            R_ProgramParameter1f("FOGDENSITY", refdef.fogColor[3]);
            R_ProgramParameter2fv("FOGRANGE", fogRange);
        } else {
            R_ProgramParameter1f("FOGDENSITY", 0.0f);
        }
    }
}

static void R_InitWarpProgram (r_program_t* prog)
{
    static vec4_t offset;

    R_ProgramParameter1i("SAMPLER_DIFFUSE", 0);
    R_ProgramParameter1i("SAMPLER_WARP", 1);
    R_ProgramParameter1i("SAMPLER_GLOWMAP", 4);
    R_ProgramParameter1f("GLOWSCALE", 0.0);
    R_ProgramParameter4fv("OFFSET", offset);
    if (r_fog->integer) {
        if (r_state.fog_enabled) {
            R_ProgramParameter3fv("FOGCOLOR", refdef.fogColor);
            R_ProgramParameter1f("FOGDENSITY", refdef.fogColor[3]);
            R_ProgramParameter2fv("FOGRANGE", fogRange);
        } else {
            R_ProgramParameter1f("FOGDENSITY", 0.0f);
        }
    }
}

static void R_UseWarpProgram (r_program_t* prog)
{
    static vec4_t offset;

    offset[0] = offset[1] = refdef.time / 8.0;
    R_ProgramParameter4fv("OFFSET", offset);
    if (r_fog->integer) {
        if (r_state.fog_enabled) {
            R_ProgramParameter3fv("FOGCOLOR", refdef.fogColor);
            R_ProgramParameter1f("FOGDENSITY", refdef.fogColor[3]);
            R_ProgramParameter2fv("FOGRANGE", fogRange);
        } else {
            R_ProgramParameter1f("FOGDENSITY", 0.0f);
        }
    }
}

static void R_InitGeoscapeProgram (r_program_t* prog)
{
    static vec4_t defaultColor = {0.0, 0.0, 0.0, 1.0};
    static vec4_t cityLightColor = {1.0, 1.0, 0.8, 1.0};
    static vec2_t uvScale = {2.0, 1.0};

    R_ProgramParameter1i("SAMPLER_DIFFUSE", 0);
    R_ProgramParameter1i("SAMPLER_BLEND", 1);
    R_ProgramParameter1i("SAMPLER_NORMALMAP", 2);

    R_ProgramParameter4fv("DEFAULTCOLOR", defaultColor);
    R_ProgramParameter4fv("CITYLIGHTCOLOR", cityLightColor);
    R_ProgramParameter2fv("UVSCALE", uvScale);
}

static int R_PascalTriangle (int row, int col)
{
    if (row <= 1 || col <= 1 || col >= row)
        return 1;
    return R_PascalTriangle(row - 1, col) + R_PascalTriangle(row - 1, col - 1);
}

#define FILTER_SIZE 3

static void R_InitConvolveProgram (r_program_t* prog)
{
    float filter[FILTER_SIZE];
    float sum = 0;
    int i;
    const size_t size = lengthof(filter);

    /* approximate a Gaussian by normalizing the Nth row of Pascale's Triangle */
    for (i = 0; i < size; i++) {
        filter[i] = (float)R_PascalTriangle(size, i + 1);
        sum += filter[i];
    }

    for (i = 0; i < size; i++)
        filter[i] = (filter[i] / sum);

    R_ProgramParameter1i("SAMPLER0", 0);
    R_ProgramParameter1fvs("COEFFICIENTS", size, filter);
}

static void R_UseConvolveProgram (r_program_t* prog)
{
    const float* userdata= (float*)prog->userdata;
    float offsets[FILTER_SIZE * 2];
    const float halfWidth = (FILTER_SIZE - 1) * 0.5;
    const float offset = 1.2f / userdata[0];
    const float x = userdata[1] * offset;

    for (int i = 0; i < FILTER_SIZE; i++) {
        const float y = (float)i - halfWidth;
        const float z = x * y;
        offsets[i * 2 + 0] = offset * y - z;
        offsets[i * 2 + 1] = z;
    }
    R_ProgramParameter2fvs("OFFSETS", FILTER_SIZE, offsets);
}

static void R_InitCombine2Program (r_program_t* prog)
{
    GLfloat defaultColor[4] = {0.0, 0.0, 0.0, 0.0};

    R_ProgramParameter1i("SAMPLER0", 0);
    R_ProgramParameter1i("SAMPLER1", 1);

    R_ProgramParameter4fv("DEFAULTCOLOR", defaultColor);
}

static void R_InitAtmosphereProgram (r_program_t* prog)
{
    static vec4_t defaultColor = {0.0, 0.0, 0.0, 1.0};
    static vec2_t uvScale = {2.0, 1.0};

    R_ProgramParameter1i("SAMPLER_DIFFUSE", 0);
    R_ProgramParameter1i("SAMPLER_NORMALMAP", 2);

    R_ProgramParameter4fv("DEFAULTCOLOR", defaultColor);
    R_ProgramParameter2fv("UVSCALE", uvScale);
}

static void R_InitSimpleGlowProgram (r_program_t* prog)
{
    R_ProgramParameter1i("SAMPLER_DIFFUSE", 0);
    R_ProgramParameter1i("SAMPLER_GLOWMAP", 4);
    R_ProgramParameter1f("GLOWSCALE", 1.0);
}

void R_InitParticleProgram (r_program_t* prog)
{
    R_ProgramParameter1i("SAMPLER0", 0);
}

void R_UseParticleProgram (r_program_t* prog)
{
/*  ptl_t* ptl = (ptl_t*)prog->userdata;*/
}

void R_InitPrograms (void)
{
    if (!qglCreateProgram) {
        Com_Printf("not using GLSL shaders\n");
        Cvar_Set("r_programs", "0");
        r_programs->modified = false;
        return;
    }

    OBJZERO(r_state.shaders);
    OBJZERO(r_state.programs);

    /* Capable of running shaders, but have got them disabled, so do nothing */
    if (!r_programs->integer)
        return;

    r_state.world_program = R_LoadProgram(shaderQualityLevelNames[r_programs->integer - 1][0], R_InitWorldProgram, R_UseWorldProgram);
    r_state.model_program = R_LoadProgram(shaderQualityLevelNames[r_programs->integer - 1][1], R_InitModelProgram, R_UseModelProgram);
    r_state.warp_program = R_LoadProgram("warp", R_InitWarpProgram, R_UseWarpProgram);
    r_state.geoscape_program = R_LoadProgram("geoscape", R_InitGeoscapeProgram, nullptr);
    r_state.combine2_program = R_LoadProgram("combine2", R_InitCombine2Program, nullptr);
    r_state.convolve_program = R_LoadProgram("convolve" DOUBLEQUOTE(FILTER_SIZE), R_InitConvolveProgram, R_UseConvolveProgram);
    r_state.atmosphere_program = R_LoadProgram("atmosphere", R_InitAtmosphereProgram, nullptr);
    r_state.simple_glow_program = R_LoadProgram("simple_glow", R_InitSimpleGlowProgram, nullptr);

    if (!(r_state.world_program && r_state.model_program && r_state.warp_program && r_state.geoscape_program && r_state.combine2_program
        && r_state.convolve_program && r_state.atmosphere_program && r_state.simple_glow_program)) {
        Com_Printf("disabled shaders because they failed to compile\n");
        Cvar_Set("r_programs", "0");
        r_programs->modified = false;
    }
}

void R_RestartPrograms_f (void)
{
    if (r_programs->integer) {
        Com_Printf("glsl restart to a version of v%s\n", Cvar_Get("r_glsl_version", nullptr, 0, nullptr)->string);
    } else {
        Com_Printf("glsl shutdown\n");
    }

    R_ShutdownPrograms();
    R_InitPrograms();
    R_InitFBObjects();
}