texture_env.cpp

#include <windows.h>
#include "OpenGL.h"
#include "Combiner.h"
#include "texture_env.h"

void Init_texture_env()
{
}

void Uninit_texture_env()
{
}

void Update_texture_env_Colors(TexEnv* texEnv)
{
}

TexEnv* Compile_texture_env(Combiner* color, Combiner* alpha)
{
    auto texEnv = (TexEnv*)malloc(sizeof(TexEnv));

    texEnv->usesT0 = FALSE;
    texEnv->usesT1 = FALSE;

    texEnv->fragment.color = texEnv->fragment.alpha = COMBINED;

    for (int i = 0; i < alpha->numStages; i++)
    {
        for (int j = 0; j < alpha->stage[i].numOps; j++)
        {
            switch (alpha->stage[i].op[j].op)
            {
            case LOAD:
                if ((alpha->stage[i].op[j].param1 != TEXEL0_ALPHA) && (alpha->stage[i].op[j].param1 != TEXEL1_ALPHA))
                {
                    texEnv->fragment.alpha = alpha->stage[i].op[j].param1;
                    texEnv->usesT0 = FALSE;
                    texEnv->usesT1 = FALSE;
                }
                else
                {
                    texEnv->mode = GL_REPLACE;

                    texEnv->usesT0 = alpha->stage[i].op[j].param1 == TEXEL0_ALPHA;
                    texEnv->usesT1 = alpha->stage[i].op[j].param1 == TEXEL1_ALPHA;
                }
                break;
            case SUB:
                break;
            case MUL:
                if (((alpha->stage[i].op[j].param1 == TEXEL0_ALPHA) || (alpha->stage[i].op[j].param1 == TEXEL1_ALPHA)) &&
                    ((alpha->stage[i].op[j - 1].param1 != TEXEL0_ALPHA) || (alpha->stage[i].op[j - 1].param1 != TEXEL1_ALPHA)))
                {
                    texEnv->mode = GL_MODULATE;
                }
                else if (((alpha->stage[i].op[j].param1 != TEXEL0_ALPHA) || (alpha->stage[i].op[j].param1 != TEXEL1_ALPHA)) &&
                    ((alpha->stage[i].op[j - 1].param1 == TEXEL0_ALPHA) || (alpha->stage[i].op[j - 1].param1 == TEXEL1_ALPHA)))
                {
                    texEnv->fragment.alpha = alpha->stage[i].op[j].param1;
                    texEnv->mode = GL_MODULATE;
                }
                break;
            case ADD:
                break;
            case INTER:
                break;
            }
        }
    }

    for (int i = 0; i < color->numStages; i++)
    {
        for (int j = 0; j < color->stage[i].numOps; j++)
        {
            switch (color->stage[i].op[j].op)
            {
            case LOAD:
                if ((color->stage[i].op[j].param1 == TEXEL0) || (color->stage[i].op[j].param1 == TEXEL0_ALPHA))
                {
                    if (texEnv->mode == GL_MODULATE)
                        texEnv->fragment.color = ONE;

                    texEnv->usesT0 = TRUE;
                    texEnv->usesT1 = FALSE;
                }
                else if ((color->stage[i].op[j].param1 == TEXEL1) || (color->stage[i].op[j].param1 == TEXEL1_ALPHA))
                {
                    if (texEnv->mode == GL_MODULATE)
                        texEnv->fragment.color = ONE;

                    texEnv->usesT0 = FALSE;
                    texEnv->usesT1 = TRUE;
                }
                else
                {
                    texEnv->fragment.color = color->stage[i].op[j].param1;
                    texEnv->usesT0 = texEnv->usesT1 = FALSE;
                }
                break;
            case SUB:
                break;
            case MUL:
                if ((color->stage[i].op[j].param1 == TEXEL0) || (color->stage[i].op[j].param1 == TEXEL0_ALPHA))
                {
                    if (!texEnv->usesT0 && !texEnv->usesT1)
                    {
                        texEnv->mode = GL_MODULATE;
                        texEnv->usesT0 = TRUE;
                        texEnv->usesT1 = FALSE;
                    }
                }
                else if ((color->stage[i].op[j].param1 == TEXEL1) || (color->stage[i].op[j].param1 == TEXEL1_ALPHA))
                {
                    if (!texEnv->usesT0 && !texEnv->usesT1)
                    {
                        texEnv->mode = GL_MODULATE;
                        texEnv->usesT0 = FALSE;
                        texEnv->usesT1 = TRUE;
                    }
                }
                else if (texEnv->usesT0 || texEnv->usesT1)
                {
                    texEnv->mode = GL_MODULATE;
                    texEnv->fragment.color = color->stage[i].op[j].param1;
                }
                break;
            case ADD:
                break;
            case INTER:
                if ((color->stage[i].op[j].param1 == TEXEL0) &&
                    ((color->stage[i].op[j].param2 != TEXEL0) && (color->stage[i].op[j].param2 != TEXEL0_ALPHA) &&
                        (color->stage[i].op[j].param2 != TEXEL1) && (color->stage[i].op[j].param2 != TEXEL1_ALPHA)) &&
                    (color->stage[i].op[j].param3 == TEXEL0_ALPHA))
                {
                    texEnv->mode = GL_DECAL;
                    texEnv->fragment.color = color->stage[i].op[j].param2;
                    texEnv->usesT0 = TRUE;
                    texEnv->usesT1 = FALSE;
                }
                else if ((color->stage[i].op[j].param1 == TEXEL0) &&
                    ((color->stage[i].op[j].param2 != TEXEL0) && (color->stage[i].op[j].param2 != TEXEL0_ALPHA) &&
                        (color->stage[i].op[j].param2 != TEXEL1) && (color->stage[i].op[j].param2 != TEXEL1_ALPHA)) &&
                    (color->stage[i].op[j].param3 == TEXEL0_ALPHA))
                {
                    texEnv->mode = GL_DECAL;
                    texEnv->fragment.color = color->stage[i].op[j].param2;
                    texEnv->usesT0 = FALSE;
                    texEnv->usesT1 = TRUE;
                }
                break;
            }
        }
    }

    return texEnv;
}


void Set_texture_env(TexEnv* texEnv)
{
    combiner.usesT0 = texEnv->usesT0;
    combiner.usesT1 = texEnv->usesT1;
    combiner.usesNoise = FALSE;

    combiner.vertex.color = texEnv->fragment.color;
    combiner.vertex.secondaryColor = COMBINED;
    combiner.vertex.alpha = texEnv->fragment.alpha;

    // Shouldn't ever happen, but who knows?
    if (OGL.ARB_multitexture)
        glActiveTextureARB(GL_TEXTURE0_ARB);

    if (texEnv->usesT0 || texEnv->usesT1)
        glEnable(GL_TEXTURE_2D);
    else
        glDisable(GL_TEXTURE_2D);

    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, texEnv->mode);
}