PSP Engines: Alpha 2D Pics

[Baker]

The ability to render translucent 2D textures via alpha in Kurok PSP is broke --- this is referring to the HUD, console, etc. Actually it isn't actually broke, it was reworked by MDave to save memory specifically for Kurok's virtually all black console by reusing a small texture over and over again.

Either way, the function name is misleading and isn't useful for anything except the Kurok HUD.

There is a part 2 to this: I want the ability to render masked 2D textures with alpha and that isn't supported in the source either.

Here are solutions to #1 and #2

#1: Render 2D graphics (sbar.c, console, whatever) with alpha

Open video_hardware_draw.cpp --- this is the equivalent of gl_draw.c in GLQuake --- and replace the entire function with this one.

Code: Select all

/*
=============
Draw_AlphaPic
=============
*/
void Draw_AlphaPic (int x, int y, qpic_t *pic, float alpha)
{
   if (alpha != 1.0f)
   {
      sceGuTexFunc(GU_TFX_DECAL, GU_TCC_RGBA);
   }

   glpic_t         *gl;

#if 0
   if (scrap_dirty)
      Scrap_Upload ();
#endif
   gl = (glpic_t *)pic->data;
   GL_Bind (gl->index);

   struct vertex
   {
      short         u, v;
      short         x, y, z;
   };

    vertex* const vertices = static_cast<vertex*>(sceGuGetMemory(sizeof(vertex) * 2));

   vertices[0].u      = 0;
    vertices[0].v      = 0;
    vertices[0].x      = x;
    vertices[0].y      = y;
    vertices[0].z      = 0;

   const gltexture_t& glt = gltextures[gl->index];
    vertices[1].u      = glt.original_width;
    vertices[1].v      = glt.original_height;
    vertices[1].x      = x + pic->width;
    vertices[1].y      = y + pic->height;
    vertices[1].z      = 0;

    sceGuColor(GU_RGBA(0xff, 0xff, 0xff, static_cast<unsigned int>(alpha * 255.0f)));
    sceGuDrawArray(
      GU_SPRITES,
      GU_TEXTURE_16BIT | GU_VERTEX_16BIT | GU_TRANSFORM_2D,
      2, 0, vertices);

   if (alpha != 1.0f)
   {
      sceGuTexFunc(GU_TFX_REPLACE, GU_TCC_RGBA);
   }
}

#2 and the solution for drawing transparency masked 2D textures with alpha

Code: Select all

/*
=============
Draw_AlphaTransPic
=============
*/
void Draw_AlphaTransPic (int x, int y, qpic_t *pic, float alpha)
{
   if (x < 0 || (unsigned)(x + pic->width) > vid.width || y < 0 ||
       (unsigned)(y + pic->height) > vid.height)
   {
      Sys_Error ("Draw_TransPic: bad coordinates");
   }

   if (alpha != 1.0f)
   {   // filter

      sceGuEnable(GU_BLEND);
      sceGuDisable(GU_FOG);

      sceGuBlendFunc(GU_ADD, GU_SRC_ALPHA, GU_FIX, 0, 0xFFFFFFFF);
      sceGuTexFunc(GU_TFX_MODULATE , GU_TCC_RGB);
   }

   glpic_t         *gl;

#if 0
   if (scrap_dirty)
      Scrap_Upload ();
#endif
   gl = (glpic_t *)pic->data;
   GL_Bind (gl->index);

   struct vertex
   {
      short         u, v;
      short         x, y, z;
   };

   vertex* const vertices = static_cast<vertex*>(sceGuGetMemory(sizeof(vertex) * 2));

   vertices[0].u      = 0;
   vertices[0].v      = 0;
   vertices[0].x      = x;
   vertices[0].y      = y;
   vertices[0].z      = 0;

   const gltexture_t& glt = gltextures[gl->index];
   vertices[1].u      = glt.original_width;
   vertices[1].v      = glt.original_height;
   vertices[1].x      = x + pic->width;
   vertices[1].y      = y + pic->height;
   vertices[1].z      = 0;

   sceGuColor(GU_RGBA(0xff, 0xff, 0xff, static_cast<unsigned int>(alpha * 255.0f)));
   sceGuDrawArray(
      GU_SPRITES,
      GU_TEXTURE_16BIT | GU_VERTEX_16BIT | GU_TRANSFORM_2D,
      2, 0, vertices);

   if (alpha != 1.0f)
   {
      sceGuDisable(GU_BLEND);
      sceGuEnable(GU_FOG);
      sceGuTexFunc(GU_TFX_REPLACE, GU_TCC_RGBA);

      sceGuBlendFunc(GU_ADD, GU_SRC_ALPHA, GU_ONE_MINUS_SRC_ALPHA, 0, 0);
   }
}


Now last a small footnote: since to me it is important to retain full Kurok backwards compatibility I actually did keep MDave's code. I just renamed the function and only call it if the Kurok mod is being run.

[Mexicouger]

Thanks again baker
Improving our engines so much. Making game Quality better. I think I learn Alot by this and Comparing Kurok engine code to yours And DQuake

[Jukki]

do the pinky parts be transparent?

[Mexicouger]

do the pinky parts be transparent?

If you use method 2, yes

[Jukki]

idk why. I apply this but it makes the game act wierd. every pinky that should be (used transparent one) is black :/

[Mexicouger]

idk why. I apply this but it makes the game act wierd. every pinky that should be (used transparent one) is black :/

Well for me, Every image and text that had no alpha parameters, had black around it. But the actual images that had Alpha applied to it were just fine