t_vb_cliptmp.h File Reference

Defines
#define	CLIP_DOTPROD(K, A, B, C, D)   X(K)*A + Y(K)*B + Z(K)*C + W(K)*D
#define	POLY_CLIP(PLANE_BIT, A, B, C, D)
#define	LINE_CLIP(PLANE_BIT, A, B, C, D)
Functions
static INLINE void TAG()	clip_line (GLcontext *ctx, GLuint v0, GLuint v1, GLubyte mask)
static INLINE void TAG()	clip_tri (GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLubyte mask)
static INLINE void TAG()	clip_quad (GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint v3, GLubyte mask)

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Define Documentation

#define CLIP_DOTPROD	(	K,
		A,
		B,
		C,
		D		)	X(K)*A + Y(K)*B + Z(K)*C + W(K)*D

#define LINE_CLIP	(	PLANE_BIT,
		A,
		B,
		C,
		D		)

Value:

do {                                                                    \
   if (mask & PLANE_BIT) {                                              \
      const GLfloat dp0 = CLIP_DOTPROD( v0, A, B, C, D );               \
      const GLfloat dp1 = CLIP_DOTPROD( v1, A, B, C, D );               \
      const GLboolean neg_dp0 = IS_NEGATIVE(dp0);                       \
      const GLboolean neg_dp1 = IS_NEGATIVE(dp1);                       \
                                                                        \
      /* For regular clipping, we know from the clipmask that one       \
       * (or both) of these must be negative (otherwise we wouldn't     \
       * be here).                                                      \
       * For userclip, there is only a single bit for all active        \
       * planes, so we can end up here when there is nothing to do,     \
       * hence the second IS_NEGATIVE() test:                           \
       */                                                               \
      if (neg_dp0 && neg_dp1)                                           \
         return; /* both vertices outside clip plane: discard */        \
                                                                        \
      if (neg_dp1) {                                                    \
         GLfloat t = dp1 / (dp1 - dp0);                                 \
         if (t > t1) t1 = t;                                            \
      } else if (neg_dp0) {                                             \
         GLfloat t = dp0 / (dp0 - dp1);                                 \
         if (t > t0) t0 = t;                                            \
      }                                                                 \
      if (t0 + t1 >= 1.0)                                               \
         return; /* discard */                                          \
   }                                                                    \
} while (0)

#define POLY_CLIP	(	PLANE_BIT,
		A,
		B,
		C,
		D		)

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Function Documentation

static INLINE void TAG() clip_line	(	GLcontext *	ctx,
		GLuint	v0,
		GLuint	v1,
		GLubyte	mask
	)			[static]

static INLINE void TAG() clip_quad	(	GLcontext *	ctx,
		GLuint	v0,
		GLuint	v1,
		GLuint	v2,
		GLuint	v3,
		GLubyte	mask
	)			[static]

static INLINE void TAG() clip_tri	(	GLcontext *	ctx,
		GLuint	v0,
		GLuint	v1,
		GLuint	v2,
		GLubyte	mask
	)			[static]

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