- const int n_vect = 3; /* highest vector number in each microtile */
- const int n_comp = 4; /* 4 components: R, G, B, A */
- float vec[1 + 1 + 1][MAX_COMP]; /* 1.5 extrema for each sub-block */
- float b, iv[MAX_COMP]; /* interpolation vector */
- int i, j, k;
- qword hi; /* high quadword */
- dword lohi, lolo; /* low quadword: hi dword, lo dword */
-
- int minSum;
- int maxSum;
- int minColL = 0, maxColL = 0;
- int minColR = 0, maxColR = 0;
- int sumL = 0, sumR = 0;
-
- /* Our solution here is to find the darkest and brightest colors in
- * the 4x4 tile and use those as the two representative colors.
- * There are probably better algorithms to use (histogram-based).
- */
-#ifndef YUV
- minSum = 2000; /* big enough */
-#else
- minSum = 2000000;
-#endif
- maxSum = -1; /* small enough */
- for (k = 0; k < N_TEXELS / 2; k++) {
- int sum = 0;
-#ifndef YUV
- for (i = 0; i < n_comp; i++) {
- sum += input[k][i];
- }
-#else
- sum = 299 * input[k][RCOMP] + 587 * input[k][GCOMP] + 114 * input[k][BCOMP];
-#endif
- if (minSum > sum) {
- minSum = sum;
- minColL = k;
- }
- if (maxSum < sum) {
- maxSum = sum;
- maxColL = k;
- }
- sumL += sum;
- }
-#ifndef YUV
- minSum = 2000; /* big enough */
-#else
- minSum = 2000000;
-#endif
- maxSum = -1; /* small enough */
- for (; k < N_TEXELS; k++) {
- int sum = 0;
-#ifndef YUV
- for (i = 0; i < n_comp; i++) {
- sum += input[k][i];
- }
-#else
- sum = 299 * input[k][RCOMP] + 587 * input[k][GCOMP] + 114 * input[k][BCOMP];
-#endif
- if (minSum > sum) {
- minSum = sum;
- minColR = k;
- }
- if (maxSum < sum) {
- maxSum = sum;
- maxColR = k;
- }
- sumR += sum;
- }
-
- /* choose the common vector (yuck!) */
- {
- int j1, j2;
- int v1 = 0, v2 = 0;
- float err = 1e9; /* big enough */
- float tv[2 * 2][MAX_COMP]; /* 2 extrema for each sub-block */
- for (i = 0; i < n_comp; i++) {
- tv[0][i] = input[minColL][i];
- tv[1][i] = input[maxColL][i];
- tv[2][i] = input[minColR][i];
- tv[3][i] = input[maxColR][i];
- }
- for (j1 = 0; j1 < 2; j1++) {
- for (j2 = 2; j2 < 4; j2++) {
- float e = 0.0F;
- for (i = 0; i < n_comp; i++) {
- e += (tv[j1][i] - tv[j2][i]) * (tv[j1][i] - tv[j2][i]);
- }
- if (e < err) {
- err = e;
- v1 = j1;
- v2 = j2;
- }
- }
- }
- for (i = 0; i < n_comp; i++) {
- vec[0][i] = tv[1 - v1][i];
- vec[1][i] = (tv[v1][i] * sumL + tv[v2][i] * sumR) / (sumL + sumR);
- vec[2][i] = tv[5 - v2][i];
- }
- }
-
- /* left microtile */
- cc[0] = 0;
- if (minColL != maxColL) {
- /* compute interpolation vector */
- MAKEIVEC(n_vect, n_comp, iv, b, vec[0], vec[1]);
-
- /* add in texels */
- lolo = 0;
- for (k = N_TEXELS / 2 - 1; k >= 0; k--) {
- int texel;
- /* interpolate color */
- CALCCDOT(texel, n_vect, n_comp, iv, b, input[k]);
- /* add in texel */
- lolo <<= 2;
- lolo |= texel;
- }
-
- cc[0] = lolo;
- }
-
- /* right microtile */
- cc[1] = 0;
- if (minColR != maxColR) {
- /* compute interpolation vector */
- MAKEIVEC(n_vect, n_comp, iv, b, vec[2], vec[1]);
-
- /* add in texels */
- lohi = 0;
- for (k = N_TEXELS - 1; k >= N_TEXELS / 2; k--) {
- int texel;
- /* interpolate color */
- CALCCDOT(texel, n_vect, n_comp, iv, b, input[k]);
- /* add in texel */
- lohi <<= 2;
- lohi |= texel;
- }
-
- cc[1] = lohi;
- }
-
- Q_MOV32(hi, 7); /* alpha = "011" + lerp = 1 */
- for (j = n_vect - 1; j >= 0; j--) {
- /* add in alphas */
- Q_SHL(hi, 5);
- Q_OR32(hi, (dword)(vec[j][ACOMP] / 8.0F));
- }
- for (j = n_vect - 1; j >= 0; j--) {
- for (i = 0; i < n_comp - 1; i++) {
- /* add in colors */
- Q_SHL(hi, 5);
- Q_OR32(hi, (dword)(vec[j][i] / 8.0F));
- }
- }
- ((qword *)cc)[1] = hi;
+ const int n_vect = 3; /* highest vector number in each microtile */
+ const int n_comp = 4; /* 4 components: R, G, B, A */
+ float vec[1 + 1 + 1][MAX_COMP]; /* 1.5 extrema for each sub-block */
+ float b, iv[MAX_COMP]; /* interpolation vector */
+ int i, j, k;
+ qword hi; /* high quadword */
+ dword lohi, lolo; /* low quadword: hi dword, lo dword */
+
+ int minSum;
+ int maxSum;
+ int minColL = 0, maxColL = 0;
+ int minColR = 0, maxColR = 0;
+ int sumL = 0, sumR = 0;
+ int nn_comp;
+ /* Our solution here is to find the darkest and brightest colors in
+ * the 4x4 tile and use those as the two representative colors.
+ * There are probably better algorithms to use (histogram-based).
+ */
+ nn_comp = n_comp;
+ while ((minColL == maxColL) && nn_comp) {
+ minSum = 2000; /* big enough */
+ maxSum = -1; /* small enough */
+ for (k = 0; k < N_TEXELS / 2; k++) {
+ int sum = 0;
+ for (i = 0; i < nn_comp; i++) {
+ sum += input[k][i];
+ }
+ if (minSum > sum) {
+ minSum = sum;
+ minColL = k;
+ }
+ if (maxSum < sum) {
+ maxSum = sum;
+ maxColL = k;
+ }
+ sumL += sum;
+ }
+
+ nn_comp--;
+ }
+
+ nn_comp = n_comp;
+ while ((minColR == maxColR) && nn_comp) {
+ minSum = 2000; /* big enough */
+ maxSum = -1; /* small enough */
+ for (k = N_TEXELS / 2; k < N_TEXELS; k++) {
+ int sum = 0;
+ for (i = 0; i < nn_comp; i++) {
+ sum += input[k][i];
+ }
+ if (minSum > sum) {
+ minSum = sum;
+ minColR = k;
+ }
+ if (maxSum < sum) {
+ maxSum = sum;
+ maxColR = k;
+ }
+ sumR += sum;
+ }
+
+ nn_comp--;
+ }
+
+ /* choose the common vector (yuck!) */
+ {
+ int j1, j2;
+ int v1 = 0, v2 = 0;
+ float err = 1e9; /* big enough */
+ float tv[2 * 2][MAX_COMP]; /* 2 extrema for each sub-block */
+ for (i = 0; i < n_comp; i++) {
+ tv[0][i] = input[minColL][i];
+ tv[1][i] = input[maxColL][i];
+ tv[2][i] = input[minColR][i];
+ tv[3][i] = input[maxColR][i];
+ }
+ for (j1 = 0; j1 < 2; j1++) {
+ for (j2 = 2; j2 < 4; j2++) {
+ float e = 0.0F;
+ for (i = 0; i < n_comp; i++) {
+ e += (tv[j1][i] - tv[j2][i]) * (tv[j1][i] - tv[j2][i]);
+ }
+ if (e < err) {
+ err = e;
+ v1 = j1;
+ v2 = j2;
+ }
+ }
+ }
+ for (i = 0; i < n_comp; i++) {
+ vec[0][i] = tv[1 - v1][i];
+ vec[1][i] = (tv[v1][i] * sumL + tv[v2][i] * sumR) / (sumL + sumR);
+ vec[2][i] = tv[5 - v2][i];
+ }
+ }
+
+ /* left microtile */
+ cc[0] = 0;
+ if (minColL != maxColL) {
+ /* compute interpolation vector */
+ MAKEIVEC(n_vect, n_comp, iv, b, vec[0], vec[1]);
+
+ /* add in texels */
+ lolo = 0;
+ for (k = N_TEXELS / 2 - 1; k >= 0; k--) {
+ int texel;
+ /* interpolate color */
+ CALCCDOT(texel, n_vect, n_comp, iv, b, input[k]);
+ /* add in texel */
+ lolo <<= 2;
+ lolo |= texel;
+ }
+
+ cc[0] = lolo;
+ }
+
+ /* right microtile */
+ cc[1] = 0;
+ if (minColR != maxColR) {
+ /* compute interpolation vector */
+ MAKEIVEC(n_vect, n_comp, iv, b, vec[2], vec[1]);
+
+ /* add in texels */
+ lohi = 0;
+ for (k = N_TEXELS - 1; k >= N_TEXELS / 2; k--) {
+ int texel;
+ /* interpolate color */
+ CALCCDOT(texel, n_vect, n_comp, iv, b, input[k]);
+ /* add in texel */
+ lohi <<= 2;
+ lohi |= texel;
+ }
+
+ cc[1] = lohi;
+ }
+
+ Q_MOV32(hi, 7); /* alpha = "011" + lerp = 1 */
+ for (j = n_vect - 1; j >= 0; j--) {
+ /* add in alphas */
+ Q_SHL(hi, 5);
+ Q_OR32(hi, (dword)(vec[j][ACOMP] / 8.0F));
+ }
+ for (j = n_vect - 1; j >= 0; j--) {
+ for (i = 0; i < n_comp - 1; i++) {
+ /* add in colors */
+ Q_SHL(hi, 5);
+ Q_OR32(hi, (dword)(vec[j][i] / 8.0F));
+ }
+ }
+ ((qword *)cc)[1] = hi;