s_triangle.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

              tex11 -= info->tbytesline;				\
           }								\
           DO_TEX;							\
           span->red += span->redStep;					\
	   span->green += span->greenStep;				\
           span->blue += span->blueStep;				\
	   span->alpha += span->alphaStep;				\
	   span->intTex[0] += span->intTexStep[0];			\
	   span->intTex[1] += span->intTexStep[1];			\
           dest += 4;							\
	}


   GLuint i;
   GLchan *dest = span->array->rgba[0];

   span->intTex[0] -= FIXED_HALF;
   span->intTex[1] -= FIXED_HALF;
   switch (info->filter) {
   case GL_NEAREST:
      switch (info->format) {
      case GL_RGB:
         switch (info->envmode) {
         case GL_MODULATE:
            SPAN_NEAREST(NEAREST_RGB;MODULATE,3);
            break;
         case GL_DECAL:
         case GL_REPLACE:
            SPAN_NEAREST(NEAREST_RGB_REPLACE,3);
            break;
         case GL_BLEND:
            SPAN_NEAREST(NEAREST_RGB;BLEND,3);
            break;
         case GL_ADD:
            SPAN_NEAREST(NEAREST_RGB;ADD,3);
            break;
         default:
            _mesa_problem(ctx, "bad tex env mode in SPAN_LINEAR");
            return;
         }
         break;
      case GL_RGBA:
         switch(info->envmode) {
         case GL_MODULATE:
            SPAN_NEAREST(NEAREST_RGBA;MODULATE,4);
            break;
         case GL_DECAL:
            SPAN_NEAREST(NEAREST_RGBA;DECAL,4);
            break;
         case GL_BLEND:
            SPAN_NEAREST(NEAREST_RGBA;BLEND,4);
            break;
         case GL_ADD:
            SPAN_NEAREST(NEAREST_RGBA;ADD,4);
            break;
         case GL_REPLACE:
            SPAN_NEAREST(NEAREST_RGBA_REPLACE,4);
            break;
         default:
            _mesa_problem(ctx, "bad tex env mode (2) in SPAN_LINEAR");
            return;
         }
         break;
      }
      break;

   case GL_LINEAR:
      span->intTex[0] -= FIXED_HALF;
      span->intTex[1] -= FIXED_HALF;
      switch (info->format) {
      case GL_RGB:
         switch (info->envmode) {
         case GL_MODULATE:
            SPAN_LINEAR(LINEAR_RGB;MODULATE,3);
            break;
         case GL_DECAL:
         case GL_REPLACE:
            SPAN_LINEAR(LINEAR_RGB;REPLACE,3);
            break;
         case GL_BLEND:
            SPAN_LINEAR(LINEAR_RGB;BLEND,3);
            break;
         case GL_ADD:
            SPAN_LINEAR(LINEAR_RGB;ADD,3);
            break;
         default:
            _mesa_problem(ctx, "bad tex env mode (3) in SPAN_LINEAR");
            return;
         }
         break;
      case GL_RGBA:
         switch (info->envmode) {
         case GL_MODULATE:
            SPAN_LINEAR(LINEAR_RGBA;MODULATE,4);
            break;
         case GL_DECAL:
            SPAN_LINEAR(LINEAR_RGBA;DECAL,4);
            break;
         case GL_BLEND:
            SPAN_LINEAR(LINEAR_RGBA;BLEND,4);
            break;
         case GL_ADD:
            SPAN_LINEAR(LINEAR_RGBA;ADD,4);
            break;
         case GL_REPLACE:
            SPAN_LINEAR(LINEAR_RGBA;REPLACE,4);
            break;
         default:
            _mesa_problem(ctx, "bad tex env mode (4) in SPAN_LINEAR");
            return;
         }
         break;
      }
      break;
   }
   span->interpMask &= ~SPAN_RGBA;
   ASSERT(span->arrayMask & SPAN_RGBA);
   _swrast_write_rgba_span(ctx, span);

#undef SPAN_NEAREST
#undef SPAN_LINEAR
}



/*
 * Render an RGB/RGBA textured triangle without perspective correction.
 */
#define NAME affine_textured_triangle
#define INTERP_Z 1
#define INTERP_RGB 1
#define INTERP_ALPHA 1
#define INTERP_INT_TEX 1
#define S_SCALE twidth
#define T_SCALE theight

#define SETUP_CODE							\
   struct affine_info info;						\
   struct gl_texture_unit *unit = ctx->Texture.Unit+0;			\
   struct gl_texture_object *obj = unit->Current2D;			\
   const GLint b = obj->BaseLevel;					\
   const GLfloat twidth = (GLfloat) obj->Image[0][b]->Width;		\
   const GLfloat theight = (GLfloat) obj->Image[0][b]->Height;		\
   info.texture = (const GLchan *) obj->Image[0][b]->Data;		\
   info.twidth_log2 = obj->Image[0][b]->WidthLog2;			\
   info.smask = obj->Image[0][b]->Width - 1;				\
   info.tmask = obj->Image[0][b]->Height - 1;				\
   info.format = obj->Image[0][b]->_BaseFormat;				\
   info.filter = obj->MinFilter;					\
   info.envmode = unit->EnvMode;					\
   span.arrayMask |= SPAN_RGBA;						\
									\
   if (info.envmode == GL_BLEND) {					\
      /* potential off-by-one error here? (1.0f -> 2048 -> 0) */	\
      info.er = FloatToFixed(unit->EnvColor[RCOMP] * CHAN_MAXF);	\
      info.eg = FloatToFixed(unit->EnvColor[GCOMP] * CHAN_MAXF);	\
      info.eb = FloatToFixed(unit->EnvColor[BCOMP] * CHAN_MAXF);	\
      info.ea = FloatToFixed(unit->EnvColor[ACOMP] * CHAN_MAXF);	\
   }									\
   if (!info.texture) {							\
      /* this shouldn't happen */					\
      return;								\
   }									\
									\
   switch (info.format) {						\
   case GL_ALPHA:							\
   case GL_LUMINANCE:							\
   case GL_INTENSITY:							\
      info.tbytesline = obj->Image[0][b]->Width;			\
      break;								\
   case GL_LUMINANCE_ALPHA:						\
      info.tbytesline = obj->Image[0][b]->Width * 2;			\
      break;								\
   case GL_RGB:								\
      info.tbytesline = obj->Image[0][b]->Width * 3;			\
      break;								\
   case GL_RGBA:							\
      info.tbytesline = obj->Image[0][b]->Width * 4;			\
      break;								\
   default:								\
      _mesa_problem(NULL, "Bad texture format in affine_texture_triangle");\
      return;								\
   }									\
   info.tsize = obj->Image[0][b]->Height * info.tbytesline;

#define RENDER_SPAN( span )   affine_span(ctx, &span, &info);

#include "s_tritemp.h"



struct persp_info
{
   GLenum filter;
   GLenum format;
   GLenum envmode;
   GLint smask, tmask;
   GLint twidth_log2;
   const GLchan *texture;
   GLfixed er, eg, eb, ea;   /* texture env color */
   GLint tbytesline, tsize;
};


static INLINE void
fast_persp_span(GLcontext *ctx, SWspan *span,
		struct persp_info *info)
{
   GLchan sample[4];  /* the filtered texture sample */

  /* Instead of defining a function for each mode, a test is done
   * between the outer and inner loops. This is to reduce code size
   * and complexity. Observe that an optimizing compiler kills
   * unused variables (for instance tf,sf,ti,si in case of GL_NEAREST).
   */
#define SPAN_NEAREST(DO_TEX,COMP)					\
	for (i = 0; i < span->end; i++) {				\
           GLdouble invQ = tex_coord[2] ?				\
                                 (1.0 / tex_coord[2]) : 1.0;            \
           GLfloat s_tmp = (GLfloat) (tex_coord[0] * invQ);		\
           GLfloat t_tmp = (GLfloat) (tex_coord[1] * invQ);		\
           GLint s = IFLOOR(s_tmp) & info->smask;	        	\
           GLint t = IFLOOR(t_tmp) & info->tmask;	        	\
           GLint pos = (t << info->twidth_log2) + s;			\
           const GLchan *tex00 = info->texture + COMP * pos;		\
           DO_TEX;							\
           span->red += span->redStep;					\
	   span->green += span->greenStep;				\
           span->blue += span->blueStep;				\
	   span->alpha += span->alphaStep;				\
	   tex_coord[0] += tex_step[0];					\
	   tex_coord[1] += tex_step[1];					\
	   tex_coord[2] += tex_step[2];					\
           dest += 4;							\
	}

#define SPAN_LINEAR(DO_TEX,COMP)					\
	for (i = 0; i < span->end; i++) {				\
           GLdouble invQ = tex_coord[2] ?				\
                                 (1.0 / tex_coord[2]) : 1.0;            \
           const GLfloat s_tmp = (GLfloat) (tex_coord[0] * invQ);	\
           const GLfloat t_tmp = (GLfloat) (tex_coord[1] * invQ);	\
           const GLfixed s_fix = FloatToFixed(s_tmp) - FIXED_HALF;	\
           const GLfixed t_fix = FloatToFixed(t_tmp) - FIXED_HALF;      \
           const GLint s = FixedToInt(FixedFloor(s_fix)) & info->smask;	\
           const GLint t = FixedToInt(FixedFloor(t_fix)) & info->tmask;	\
           const GLfixed sf = s_fix & FIXED_FRAC_MASK;			\
           const GLfixed tf = t_fix & FIXED_FRAC_MASK;			\
           const GLint pos = (t << info->twidth_log2) + s;		\
           const GLchan *tex00 = info->texture + COMP * pos;		\
           const GLchan *tex10 = tex00 + info->tbytesline;		\
           const GLchan *tex01 = tex00 + COMP;				\
           const GLchan *tex11 = tex10 + COMP;				\
           if (t == info->tmask) {					\
              tex10 -= info->tsize;					\
              tex11 -= info->tsize;					\
           }								\
           if (s == info->smask) {					\
              tex01 -= info->tbytesline;				\
              tex11 -= info->tbytesline;				\
           }								\
           DO_TEX;							\
           span->red   += span->redStep;				\
	   span->green += span->greenStep;				\
           span->blue  += span->blueStep;				\
	   span->alpha += span->alphaStep;				\
	   tex_coord[0] += tex_step[0];					\
	   tex_coord[1] += tex_step[1];					\
	   tex_coord[2] += tex_step[2];					\
           dest += 4;							\
	}

   GLuint i;
   GLfloat tex_coord[3], tex_step[3];
   GLchan *dest = span->array->rgba[0];

   const GLuint savedTexEnable = ctx->Texture._EnabledUnits;
   ctx->Texture._EnabledUnits = 0;

   tex_coord[0] = span->attrStart[FRAG_ATTRIB_TEX0][0]  * (info->smask + 1);
   tex_step[0] = span->attrStepX[FRAG_ATTRIB_TEX0][0] * (info->smask + 1);
   tex_coord[1] = span->attrStart[FRAG_ATTRIB_TEX0][1] * (info->tmask + 1);
   tex_step[1] = span->attrStepX[FRAG_ATTRIB_TEX0][1] * (info->tmask + 1);
   /* span->attrStart[FRAG_ATTRIB_TEX0][2] only if 3D-texturing, here only 2D */
   tex_coord[2] = span->attrStart[FRAG_ATTRIB_TEX0][3];
   tex_step[2] = span->attrStepX[FRAG_ATTRIB_TEX0][3];

   switch (info->filter) {
   case GL_NEAREST:
      switch (info->format) {
      case GL_RGB:
         switch (info->envmode) {
         case GL_MODULATE:
            SPAN_NEAREST(NEAREST_RGB;MODULATE,3);
            break;
         case GL_DECAL:
         case GL_REPLACE:
            SPAN_NEAREST(NEAREST_RGB_REPLACE,3);
            break;
         case GL_BLEND:
            SPAN_NEAREST(NEAREST_RGB;BLEND,3);
            break;
         case GL_ADD:
            SPAN_NEAREST(NEAREST_RGB;ADD,3);
            break;
         default:
            _mesa_problem(ctx, "bad tex env mode (5) in SPAN_LINEAR");
            return;
         }
         break;
      case GL_RGBA:
         switch(info->envmode) {
         case GL_MODULATE:
            SPAN_NEAREST(NEAREST_RGBA;MODULATE,4);
            break;
         case GL_DECAL:
            SPAN_NEAREST(NEAREST_RGBA;DECAL,4);
            break;
         case GL_BLEND:
            SPAN_NEAREST(NEAREST_RGBA;BLEND,4);
            break;
         case GL_ADD:
            SPAN_NEAREST(NEAREST_RGBA;ADD,4);
            break;
         case GL_REPLACE:
            SPAN_NEAREST(NEAREST_RGBA_REPLACE,4);
            break;
         default:
            _mesa_problem(ctx, "bad tex env mode (6) in SPAN_LINEAR");
            return;
         }
         break;
      }
      break;

   case GL_LINEAR:
      switch (info->format) {
      case GL_RGB:
         switch (info->envmode) {
         case GL_MODULATE:
            SPAN_LINEAR(LINEAR_RGB;MODULATE,3);
            break;
         case GL_DECAL:
         case GL_REPLACE:
            SPAN_LINEAR(LINEAR_RGB;REPLACE,3);
            break;
         case GL_BLEND:
            SPAN_LINEAR(LINEAR_RGB;BLEND,3);
            break;
         case GL_ADD:
            SPAN_LINEAR(LINEAR_RGB;ADD,3);
            break;
         default:
            _mesa_problem(ctx, "bad tex env mode (7) in SPAN_LINEAR");
            return;
         }
         break;
      case GL_RGBA:
         switch (info->envmode) {
         case GL_MODULATE:
            SPAN_LINEAR(LINEAR_RGBA;MODULATE,4);
            break;
         case GL_DECAL:
            SPAN_LINEAR(LINEAR_RGBA;DECAL,4);
            break;
         case GL_BLEND:
            SPAN_LINEAR(LINEAR_RGBA;BLEND,4);
            break;
         case GL_ADD:
            SPAN_LINEAR(LINEAR_RGBA;ADD,4);
            break;
         case GL_REPLACE:
            SPAN_LINEAR(LINEAR_RGBA;REPLACE,4);
            break;
         default:
            _mesa_problem(ctx, "bad tex env mode (8) in SPAN_LINEAR");
            return;
         }