GL_ADD texture mode was incorrect, renamed some vars

diff --git a/src/mesa/swrast/s_triangle.c b/src/mesa/swrast/s_triangle.c
index cc447ac5707f3791d97d8b067b102148ceca7ac4..02c27d52968ec506fa59488f1184217e6b4afd8d 100644 (file)
--- a/src/mesa/swrast/s_triangle.c
+++ b/src/mesa/swrast/s_triangle.c
@@ -1,4 +1,4 @@
-/* $Id: s_triangle.c,v 1.38 2001/09/19 20:30:44 kschultz Exp $ */
+/* $Id: s_triangle.c,v 1.39 2001/09/19 22:21:13 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -344,11 +344,16 @@ struct affine_info
    GLint fixedToDepthShift;
 };
 
+
+/* This function can handle GL_NEAREST or GL_LINEAR sampling of 2D RGB or RGBA
+ * textures with GL_REPLACE, GL_MODULATE, GL_BLEND, GL_DECAL or GL_ADD
+ * texture env modes.
+ */
 static void
 affine_span(GLcontext *ctx, struct triangle_span *span,
             struct affine_info *info)
 {
-   GLchan tmp_col[4];
+   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
@@ -357,75 +362,71 @@ affine_span(GLcontext *ctx, struct triangle_span *span,
     */
 
 #define NEAREST_RGB                    \
-   tmp_col[RCOMP] = tex00[RCOMP];      \
-   tmp_col[GCOMP] = tex00[GCOMP];      \
-   tmp_col[BCOMP] = tex00[BCOMP];      \
-   tmp_col[ACOMP] = CHAN_MAX
+   sample[RCOMP] = tex00[RCOMP];       \
+   sample[GCOMP] = tex00[GCOMP];       \
+   sample[BCOMP] = tex00[BCOMP];       \
+   sample[ACOMP] = CHAN_MAX
 
 #define LINEAR_RGB                                                     \
-   tmp_col[RCOMP] = (ti * (si * tex00[0] + sf * tex01[0]) +            \
+   sample[RCOMP] = (ti * (si * tex00[0] + sf * tex01[0]) +             \
              tf * (si * tex10[0] + sf * tex11[0])) >> 2 * FIXED_SHIFT; \
-   tmp_col[GCOMP] = (ti * (si * tex00[1] + sf * tex01[1]) +            \
+   sample[GCOMP] = (ti * (si * tex00[1] + sf * tex01[1]) +             \
              tf * (si * tex10[1] + sf * tex11[1])) >> 2 * FIXED_SHIFT; \
-   tmp_col[BCOMP] = (ti * (si * tex00[2] + sf * tex01[2]) +            \
+   sample[BCOMP] = (ti * (si * tex00[2] + sf * tex01[2]) +             \
              tf * (si * tex10[2] + sf * tex11[2])) >> 2 * FIXED_SHIFT; \
-   tmp_col[ACOMP] = CHAN_MAX
+   sample[ACOMP] = CHAN_MAX
 
-#define NEAREST_RGBA  COPY_CHAN4(tmp_col, tex00)
+#define NEAREST_RGBA  COPY_CHAN4(sample, tex00)
 
 #define LINEAR_RGBA                                                    \
-   tmp_col[RCOMP] = (ti * (si * tex00[0] + sf * tex01[0]) +            \
+   sample[RCOMP] = (ti * (si * tex00[0] + sf * tex01[0]) +             \
                tf * (si * tex10[0] + sf * tex11[0])) >> 2 * FIXED_SHIFT;\
-   tmp_col[GCOMP] = (ti * (si * tex00[1] + sf * tex01[1]) +            \
+   sample[GCOMP] = (ti * (si * tex00[1] + sf * tex01[1]) +             \
                tf * (si * tex10[1] + sf * tex11[1])) >> 2 * FIXED_SHIFT;\
-   tmp_col[BCOMP] = (ti * (si * tex00[2] + sf * tex01[2]) +            \
+   sample[BCOMP] = (ti * (si * tex00[2] + sf * tex01[2]) +             \
                tf * (si * tex10[2] + sf * tex11[2])) >> 2 * FIXED_SHIFT;\
-   tmp_col[ACOMP] = (ti * (si * tex00[3] + sf * tex01[3]) +            \
+   sample[ACOMP] = (ti * (si * tex00[3] + sf * tex01[3]) +             \
                tf * (si * tex10[3] + sf * tex11[3])) >> 2 * FIXED_SHIFT
 
 #define MODULATE                                                          \
-   dest[RCOMP] = span->red   * (tmp_col[RCOMP] + 1u) >> (FIXED_SHIFT + 8); \
-   dest[GCOMP] = span->green * (tmp_col[GCOMP] + 1u) >> (FIXED_SHIFT + 8); \
-   dest[BCOMP] = span->blue  * (tmp_col[BCOMP] + 1u) >> (FIXED_SHIFT + 8); \
-   dest[ACOMP] = span->alpha * (tmp_col[ACOMP] + 1u) >> (FIXED_SHIFT + 8)
+   dest[RCOMP] = span->red   * (sample[RCOMP] + 1u) >> (FIXED_SHIFT + 8); \
+   dest[GCOMP] = span->green * (sample[GCOMP] + 1u) >> (FIXED_SHIFT + 8); \
+   dest[BCOMP] = span->blue  * (sample[BCOMP] + 1u) >> (FIXED_SHIFT + 8); \
+   dest[ACOMP] = span->alpha * (sample[ACOMP] + 1u) >> (FIXED_SHIFT + 8)
 
 #define DECAL                                                          \
-   dest[RCOMP] = ((CHAN_MAX - tmp_col[ACOMP]) * span->red +            \
-               ((tmp_col[ACOMP] + 1) * tmp_col[RCOMP] << FIXED_SHIFT)) \
+   dest[RCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->red +             \
+               ((sample[ACOMP] + 1) * sample[RCOMP] << FIXED_SHIFT))   \
                >> (FIXED_SHIFT + 8);                                   \
-   dest[GCOMP] = ((CHAN_MAX - tmp_col[ACOMP]) * span->green +          \
-               ((tmp_col[ACOMP] + 1) * tmp_col[GCOMP] << FIXED_SHIFT)) \
+   dest[GCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->green +           \
+               ((sample[ACOMP] + 1) * sample[GCOMP] << FIXED_SHIFT))   \
                >> (FIXED_SHIFT + 8);                                   \
-   dest[BCOMP] = ((CHAN_MAX - tmp_col[ACOMP]) * span->blue +           \
-               ((tmp_col[ACOMP] + 1) * tmp_col[BCOMP] << FIXED_SHIFT)) \
+   dest[BCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->blue +            \
+               ((sample[ACOMP] + 1) * sample[BCOMP] << FIXED_SHIFT))   \
                >> (FIXED_SHIFT + 8);                                   \
    dest[ACOMP] = FixedToInt(span->alpha)
 
 #define BLEND                                                          \
-   dest[RCOMP] = ((CHAN_MAX - tmp_col[RCOMP]) * span->red              \
-               + (tmp_col[RCOMP] + 1) * info->er) >> (FIXED_SHIFT + 8);        \
-   dest[GCOMP] = ((CHAN_MAX - tmp_col[GCOMP]) * span->green            \
-               + (tmp_col[GCOMP] + 1) * info->eg) >> (FIXED_SHIFT + 8);        \
-   dest[BCOMP] = ((CHAN_MAX - tmp_col[BCOMP]) * span->blue             \
-               + (tmp_col[BCOMP] + 1) * info->eb) >> (FIXED_SHIFT + 8);        \
-   dest[ACOMP] = span->alpha * (tmp_col[ACOMP] + 1) >> (FIXED_SHIFT + 8)
+   dest[RCOMP] = ((CHAN_MAX - sample[RCOMP]) * span->red               \
+               + (sample[RCOMP] + 1) * info->er) >> (FIXED_SHIFT + 8); \
+   dest[GCOMP] = ((CHAN_MAX - sample[GCOMP]) * span->green             \
+               + (sample[GCOMP] + 1) * info->eg) >> (FIXED_SHIFT + 8); \
+   dest[BCOMP] = ((CHAN_MAX - sample[BCOMP]) * span->blue              \
+               + (sample[BCOMP] + 1) * info->eb) >> (FIXED_SHIFT + 8); \
+   dest[ACOMP] = span->alpha * (sample[ACOMP] + 1) >> (FIXED_SHIFT + 8)
 
-#define REPLACE  COPY_CHAN4(dest, tmp_col)
-
-#define I2CHAN_CLAMP(I) (GLchan) ((I) & CHAN_MAX)
-   /* equivalent to '(GLchan) MIN2((I),CHAN_MAX)' */
+#define REPLACE  COPY_CHAN4(dest, sample)
 
 #define ADD                                                            \
-   dest[RCOMP] = MIN2(((span->red << 8) +                              \
-                       (tmp_col[RCOMP] + 1) * info->er)                        \
-                       >> (FIXED_SHIFT + 8), CHAN_MAX);                        \
-   dest[GCOMP] = MIN2(((span->green << 8) +                            \
-                       (tmp_col[GCOMP] + 1) * info->eg)                        \
-                       >> (FIXED_SHIFT + 8), CHAN_MAX);                        \
-   dest[RCOMP] = MIN2(((span->blue << 8) +                             \
-                       (tmp_col[BCOMP] + 1) * info->eb)                        \
-                       >> (FIXED_SHIFT + 8), CHAN_MAX);                        \
-   dest[ACOMP] = span->alpha * (tmp_col[ACOMP] + 1) >> (FIXED_SHIFT + 8)
+   {                                                                   \
+      GLint rSum = FixedToInt(span->red)   + (GLint) sample[RCOMP];    \
+      GLint gSum = FixedToInt(span->green) + (GLint) sample[GCOMP];    \
+      GLint bSum = FixedToInt(span->blue)  + (GLint) sample[BCOMP];    \
+      dest[RCOMP] = MIN2(rSum, CHAN_MAX);                              \
+      dest[GCOMP] = MIN2(gSum, CHAN_MAX);                              \
+      dest[BCOMP] = MIN2(bSum, CHAN_MAX);                              \
+      dest[ACOMP] = span->alpha * (sample[ACOMP] + 1) >> (FIXED_SHIFT + 8); \
+  }
 
 /* shortcuts */
 
@@ -687,7 +688,7 @@ struct persp_info
    GLint smask, tmask;
    GLint twidth_log2;
    const GLchan *texture;
-   GLchan er, eg, eb, ea;
+   GLchan er, eg, eb, ea;   /* texture env color */
    GLint tbytesline, tsize;
    GLint fixedToDepthShift;
 };
@@ -697,7 +698,7 @@ static void
 fast_persp_span(GLcontext *ctx, struct triangle_span *span,
                struct persp_info *info)
 {
-   GLchan tmp_col[4];
+   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