+struct sw_span {
+ GLint x, y;
+
+ /** Only need to process pixels between start <= i < end */
+ /** At this time, start is always zero. */
+ GLuint start, end;
+
+ /** This flag indicates that mask[] array is effectively filled with ones */
+ GLboolean writeAll;
+
+ /** either GL_POLYGON, GL_LINE, GL_POLYGON, GL_BITMAP */
+ GLenum primitive;
+
+ /** 0 = front-facing span, 1 = back-facing span (for two-sided stencil) */
+ GLuint facing;
+
+ /**
+ * This bitmask (of \link SpanFlags SPAN_* flags\endlink) indicates
+ * which of the x/xStep variables are relevant.
+ */
+ GLuint interpMask;
+
+ /* For horizontal spans, step is the partial derivative wrt X.
+ * For lines, step is the delta from one fragment to the next.
+ */
+#if CHAN_TYPE == GL_FLOAT
+ GLfloat red, redStep;
+ GLfloat green, greenStep;
+ GLfloat blue, blueStep;
+ GLfloat alpha, alphaStep;
+ GLfloat specRed, specRedStep;
+ GLfloat specGreen, specGreenStep;
+ GLfloat specBlue, specBlueStep;
+#else /* CHAN_TYPE == GL_UNSIGNED_BYTE or GL_UNSIGNED_SHORT */
+ GLfixed red, redStep;
+ GLfixed green, greenStep;
+ GLfixed blue, blueStep;
+ GLfixed alpha, alphaStep;
+ GLfixed specRed, specRedStep;
+ GLfixed specGreen, specGreenStep;
+ GLfixed specBlue, specBlueStep;
+#endif
+ GLfixed index, indexStep;
+ GLfixed z, zStep;
+ GLfloat fog, fogStep;
+ GLfloat tex[MAX_TEXTURE_COORD_UNITS][4]; /* s, t, r, q */
+ GLfloat texStepX[MAX_TEXTURE_COORD_UNITS][4];
+ GLfloat texStepY[MAX_TEXTURE_COORD_UNITS][4];
+ GLfixed intTex[2], intTexStep[2]; /* s, t only */
+
+ /* partial derivatives wrt X and Y. */
+ GLfloat dzdx, dzdy;
+ GLfloat w, dwdx, dwdy;
+ GLfloat drdx, drdy;
+ GLfloat dgdx, dgdy;
+ GLfloat dbdx, dbdy;
+ GLfloat dadx, dady;
+ GLfloat dsrdx, dsrdy;
+ GLfloat dsgdx, dsgdy;
+ GLfloat dsbdx, dsbdy;
+ GLfloat dfogdx, dfogdy;
+
+ /**
+ * This bitmask (of \link SpanFlags SPAN_* flags\endlink) indicates
+ * which of the fragment arrays in the span_arrays struct are relevant.
+ */
+ GLuint arrayMask;
+
+ /**
+ * We store the arrays of fragment values in a separate struct so
+ * that we can allocate sw_span structs on the stack without using
+ * a lot of memory. The span_arrays struct is about 400KB while the
+ * sw_span struct is only about 512 bytes.
+ */
+ struct span_arrays *array;
+};
+
+
+#define INIT_SPAN(S, PRIMITIVE, END, INTERP_MASK, ARRAY_MASK) \
+do { \
+ (S).primitive = (PRIMITIVE); \
+ (S).interpMask = (INTERP_MASK); \
+ (S).arrayMask = (ARRAY_MASK); \
+ (S).start = 0; \
+ (S).end = (END); \
+ (S).facing = 0; \
+ (S).array = SWRAST_CONTEXT(ctx)->SpanArrays; \
+} while (0)
+
+
+typedef void (*texture_sample_func)(GLcontext *ctx, GLuint texUnit,
+ const struct gl_texture_object *tObj,
+ GLuint n, const GLfloat texcoords[][4],
+ const GLfloat lambda[], GLchan rgba[][4]);
+