+
+/*
+ * Update the min/max values from an array of fragment colors.
+ */
+static void
+update_minmax(GLcontext *ctx, GLuint n, const GLfloat rgba[][4])
+{
+ GLuint i;
+ for (i = 0; i < n; i++) {
+ /* update mins */
+ if (rgba[i][RCOMP] < ctx->MinMax.Min[RCOMP])
+ ctx->MinMax.Min[RCOMP] = rgba[i][RCOMP];
+ if (rgba[i][GCOMP] < ctx->MinMax.Min[GCOMP])
+ ctx->MinMax.Min[GCOMP] = rgba[i][GCOMP];
+ if (rgba[i][BCOMP] < ctx->MinMax.Min[BCOMP])
+ ctx->MinMax.Min[BCOMP] = rgba[i][BCOMP];
+ if (rgba[i][ACOMP] < ctx->MinMax.Min[ACOMP])
+ ctx->MinMax.Min[ACOMP] = rgba[i][ACOMP];
+
+ /* update maxs */
+ if (rgba[i][RCOMP] > ctx->MinMax.Max[RCOMP])
+ ctx->MinMax.Max[RCOMP] = rgba[i][RCOMP];
+ if (rgba[i][GCOMP] > ctx->MinMax.Max[GCOMP])
+ ctx->MinMax.Max[GCOMP] = rgba[i][GCOMP];
+ if (rgba[i][BCOMP] > ctx->MinMax.Max[BCOMP])
+ ctx->MinMax.Max[BCOMP] = rgba[i][BCOMP];
+ if (rgba[i][ACOMP] > ctx->MinMax.Max[ACOMP])
+ ctx->MinMax.Max[ACOMP] = rgba[i][ACOMP];
+ }
+}
+
+
+/*
+ * Update the histogram values from an array of fragment colors.
+ */
+static void
+update_histogram(GLcontext *ctx, GLuint n, const GLfloat rgba[][4])
+{
+ const GLint max = ctx->Histogram.Width - 1;
+ GLfloat w = (GLfloat) max;
+ GLuint i;
+
+ if (ctx->Histogram.Width == 0)
+ return;
+
+ for (i = 0; i < n; i++) {
+ GLint ri = IROUND(rgba[i][RCOMP] * w);
+ GLint gi = IROUND(rgba[i][GCOMP] * w);
+ GLint bi = IROUND(rgba[i][BCOMP] * w);
+ GLint ai = IROUND(rgba[i][ACOMP] * w);
+ ri = CLAMP(ri, 0, max);
+ gi = CLAMP(gi, 0, max);
+ bi = CLAMP(bi, 0, max);
+ ai = CLAMP(ai, 0, max);
+ ctx->Histogram.Count[ri][RCOMP]++;
+ ctx->Histogram.Count[gi][GCOMP]++;
+ ctx->Histogram.Count[bi][BCOMP]++;
+ ctx->Histogram.Count[ai][ACOMP]++;
+ }
+}
+
+