+/**
+ * Average together four rows of a source image to produce a single new
+ * row in the dest image. It's legal for the two source rows to point
+ * to the same data. The source width must be equal to either the
+ * dest width or two times the dest width.
+ *
+ * \param datatype GL pixel type \c GL_UNSIGNED_BYTE, \c GL_UNSIGNED_SHORT,
+ * \c GL_FLOAT, etc.
+ * \param comps number of components per pixel (1..4)
+ * \param srcWidth Width of a row in the source data
+ * \param srcRowA Pointer to one of the rows of source data
+ * \param srcRowB Pointer to one of the rows of source data
+ * \param srcRowC Pointer to one of the rows of source data
+ * \param srcRowD Pointer to one of the rows of source data
+ * \param dstWidth Width of a row in the destination data
+ * \param srcRowA Pointer to the row of destination data
+ */
+static void
+do_row_3D(enum dtype datatype, uint comps, int srcWidth,
+ const void *srcRowA, const void *srcRowB,
+ const void *srcRowC, const void *srcRowD,
+ int dstWidth, void *dstRow)
+{
+ const uint k0 = (srcWidth == dstWidth) ? 0 : 1;
+ const uint colStride = (srcWidth == dstWidth) ? 1 : 2;
+ uint i, j, k;
+
+ assert(comps >= 1);
+ assert(comps <= 4);
+
+ if ((datatype == DTYPE_UBYTE) && (comps == 4)) {
+ DECLARE_ROW_POINTERS(ubyte, 4);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_3D(0);
+ FILTER_3D(1);
+ FILTER_3D(2);
+ FILTER_3D(3);
+ }
+ }
+ else if ((datatype == DTYPE_UBYTE) && (comps == 3)) {
+ DECLARE_ROW_POINTERS(ubyte, 3);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_3D(0);
+ FILTER_3D(1);
+ FILTER_3D(2);
+ }
+ }
+ else if ((datatype == DTYPE_UBYTE) && (comps == 2)) {
+ DECLARE_ROW_POINTERS(ubyte, 2);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_3D(0);
+ FILTER_3D(1);
+ }
+ }
+ else if ((datatype == DTYPE_UBYTE) && (comps == 1)) {
+ DECLARE_ROW_POINTERS(ubyte, 1);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_3D(0);
+ }
+ }
+ else if ((datatype == DTYPE_USHORT) && (comps == 4)) {
+ DECLARE_ROW_POINTERS(ushort, 4);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_3D(0);
+ FILTER_3D(1);
+ FILTER_3D(2);
+ FILTER_3D(3);
+ }
+ }
+ else if ((datatype == DTYPE_USHORT) && (comps == 3)) {
+ DECLARE_ROW_POINTERS(ushort, 3);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_3D(0);
+ FILTER_3D(1);
+ FILTER_3D(2);
+ }
+ }
+ else if ((datatype == DTYPE_USHORT) && (comps == 2)) {
+ DECLARE_ROW_POINTERS(ushort, 2);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_3D(0);
+ FILTER_3D(1);
+ }
+ }
+ else if ((datatype == DTYPE_USHORT) && (comps == 1)) {
+ DECLARE_ROW_POINTERS(ushort, 1);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_3D(0);
+ }
+ }
+ else if ((datatype == DTYPE_FLOAT) && (comps == 4)) {
+ DECLARE_ROW_POINTERS(float, 4);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_F_3D(0);
+ FILTER_F_3D(1);
+ FILTER_F_3D(2);
+ FILTER_F_3D(3);
+ }
+ }
+ else if ((datatype == DTYPE_FLOAT) && (comps == 3)) {
+ DECLARE_ROW_POINTERS(float, 3);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_F_3D(0);
+ FILTER_F_3D(1);
+ FILTER_F_3D(2);
+ }
+ }
+ else if ((datatype == DTYPE_FLOAT) && (comps == 2)) {
+ DECLARE_ROW_POINTERS(float, 2);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_F_3D(0);
+ FILTER_F_3D(1);
+ }
+ }
+ else if ((datatype == DTYPE_FLOAT) && (comps == 1)) {
+ DECLARE_ROW_POINTERS(float, 1);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_F_3D(0);
+ }
+ }
+ else if ((datatype == DTYPE_HALF_FLOAT) && (comps == 4)) {
+ DECLARE_ROW_POINTERS(half_float, 4);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_HF_3D(0);
+ FILTER_HF_3D(1);
+ FILTER_HF_3D(2);
+ FILTER_HF_3D(3);
+ }
+ }
+ else if ((datatype == DTYPE_HALF_FLOAT) && (comps == 3)) {
+ DECLARE_ROW_POINTERS(half_float, 4);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_HF_3D(0);
+ FILTER_HF_3D(1);
+ FILTER_HF_3D(2);
+ }
+ }
+ else if ((datatype == DTYPE_HALF_FLOAT) && (comps == 2)) {
+ DECLARE_ROW_POINTERS(half_float, 4);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_HF_3D(0);
+ FILTER_HF_3D(1);
+ }
+ }
+ else if ((datatype == DTYPE_HALF_FLOAT) && (comps == 1)) {
+ DECLARE_ROW_POINTERS(half_float, 4);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ FILTER_HF_3D(0);
+ }
+ }
+ else if ((datatype == DTYPE_UINT) && (comps == 1)) {
+ const uint *rowA = (const uint *) srcRowA;
+ const uint *rowB = (const uint *) srcRowB;
+ const uint *rowC = (const uint *) srcRowC;
+ const uint *rowD = (const uint *) srcRowD;
+ float *dst = (float *) dstRow;
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ const uint64_t tmp = (((uint64_t) rowA[j] + (uint64_t) rowA[k])
+ + ((uint64_t) rowB[j] + (uint64_t) rowB[k])
+ + ((uint64_t) rowC[j] + (uint64_t) rowC[k])
+ + ((uint64_t) rowD[j] + (uint64_t) rowD[k]));
+ dst[i] = (float)((double) tmp * 0.125);
+ }
+ }
+ else if ((datatype == DTYPE_USHORT_5_6_5) && (comps == 3)) {
+ DECLARE_ROW_POINTERS0(ushort);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ const int rowAr0 = rowA[j] & 0x1f;
+ const int rowAr1 = rowA[k] & 0x1f;
+ const int rowBr0 = rowB[j] & 0x1f;
+ const int rowBr1 = rowB[k] & 0x1f;
+ const int rowCr0 = rowC[j] & 0x1f;
+ const int rowCr1 = rowC[k] & 0x1f;
+ const int rowDr0 = rowD[j] & 0x1f;
+ const int rowDr1 = rowD[k] & 0x1f;
+ const int rowAg0 = (rowA[j] >> 5) & 0x3f;
+ const int rowAg1 = (rowA[k] >> 5) & 0x3f;
+ const int rowBg0 = (rowB[j] >> 5) & 0x3f;
+ const int rowBg1 = (rowB[k] >> 5) & 0x3f;
+ const int rowCg0 = (rowC[j] >> 5) & 0x3f;
+ const int rowCg1 = (rowC[k] >> 5) & 0x3f;
+ const int rowDg0 = (rowD[j] >> 5) & 0x3f;
+ const int rowDg1 = (rowD[k] >> 5) & 0x3f;
+ const int rowAb0 = (rowA[j] >> 11) & 0x1f;
+ const int rowAb1 = (rowA[k] >> 11) & 0x1f;
+ const int rowBb0 = (rowB[j] >> 11) & 0x1f;
+ const int rowBb1 = (rowB[k] >> 11) & 0x1f;
+ const int rowCb0 = (rowC[j] >> 11) & 0x1f;
+ const int rowCb1 = (rowC[k] >> 11) & 0x1f;
+ const int rowDb0 = (rowD[j] >> 11) & 0x1f;
+ const int rowDb1 = (rowD[k] >> 11) & 0x1f;
+ const int r = FILTER_SUM_3D(rowAr0, rowAr1, rowBr0, rowBr1,
+ rowCr0, rowCr1, rowDr0, rowDr1);
+ const int g = FILTER_SUM_3D(rowAg0, rowAg1, rowBg0, rowBg1,
+ rowCg0, rowCg1, rowDg0, rowDg1);
+ const int b = FILTER_SUM_3D(rowAb0, rowAb1, rowBb0, rowBb1,
+ rowCb0, rowCb1, rowDb0, rowDb1);
+ dst[i] = (b << 11) | (g << 5) | r;
+ }
+ }
+ else if ((datatype == DTYPE_USHORT_4_4_4_4) && (comps == 4)) {
+ DECLARE_ROW_POINTERS0(ushort);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ const int rowAr0 = rowA[j] & 0xf;
+ const int rowAr1 = rowA[k] & 0xf;
+ const int rowBr0 = rowB[j] & 0xf;
+ const int rowBr1 = rowB[k] & 0xf;
+ const int rowCr0 = rowC[j] & 0xf;
+ const int rowCr1 = rowC[k] & 0xf;
+ const int rowDr0 = rowD[j] & 0xf;
+ const int rowDr1 = rowD[k] & 0xf;
+ const int rowAg0 = (rowA[j] >> 4) & 0xf;
+ const int rowAg1 = (rowA[k] >> 4) & 0xf;
+ const int rowBg0 = (rowB[j] >> 4) & 0xf;
+ const int rowBg1 = (rowB[k] >> 4) & 0xf;
+ const int rowCg0 = (rowC[j] >> 4) & 0xf;
+ const int rowCg1 = (rowC[k] >> 4) & 0xf;
+ const int rowDg0 = (rowD[j] >> 4) & 0xf;
+ const int rowDg1 = (rowD[k] >> 4) & 0xf;
+ const int rowAb0 = (rowA[j] >> 8) & 0xf;
+ const int rowAb1 = (rowA[k] >> 8) & 0xf;
+ const int rowBb0 = (rowB[j] >> 8) & 0xf;
+ const int rowBb1 = (rowB[k] >> 8) & 0xf;
+ const int rowCb0 = (rowC[j] >> 8) & 0xf;
+ const int rowCb1 = (rowC[k] >> 8) & 0xf;
+ const int rowDb0 = (rowD[j] >> 8) & 0xf;
+ const int rowDb1 = (rowD[k] >> 8) & 0xf;
+ const int rowAa0 = (rowA[j] >> 12) & 0xf;
+ const int rowAa1 = (rowA[k] >> 12) & 0xf;
+ const int rowBa0 = (rowB[j] >> 12) & 0xf;
+ const int rowBa1 = (rowB[k] >> 12) & 0xf;
+ const int rowCa0 = (rowC[j] >> 12) & 0xf;
+ const int rowCa1 = (rowC[k] >> 12) & 0xf;
+ const int rowDa0 = (rowD[j] >> 12) & 0xf;
+ const int rowDa1 = (rowD[k] >> 12) & 0xf;
+ const int r = FILTER_SUM_3D(rowAr0, rowAr1, rowBr0, rowBr1,
+ rowCr0, rowCr1, rowDr0, rowDr1);
+ const int g = FILTER_SUM_3D(rowAg0, rowAg1, rowBg0, rowBg1,
+ rowCg0, rowCg1, rowDg0, rowDg1);
+ const int b = FILTER_SUM_3D(rowAb0, rowAb1, rowBb0, rowBb1,
+ rowCb0, rowCb1, rowDb0, rowDb1);
+ const int a = FILTER_SUM_3D(rowAa0, rowAa1, rowBa0, rowBa1,
+ rowCa0, rowCa1, rowDa0, rowDa1);
+
+ dst[i] = (a << 12) | (b << 8) | (g << 4) | r;
+ }
+ }
+ else if ((datatype == DTYPE_USHORT_1_5_5_5_REV) && (comps == 4)) {
+ DECLARE_ROW_POINTERS0(ushort);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ const int rowAr0 = rowA[j] & 0x1f;
+ const int rowAr1 = rowA[k] & 0x1f;
+ const int rowBr0 = rowB[j] & 0x1f;
+ const int rowBr1 = rowB[k] & 0x1f;
+ const int rowCr0 = rowC[j] & 0x1f;
+ const int rowCr1 = rowC[k] & 0x1f;
+ const int rowDr0 = rowD[j] & 0x1f;
+ const int rowDr1 = rowD[k] & 0x1f;
+ const int rowAg0 = (rowA[j] >> 5) & 0x1f;
+ const int rowAg1 = (rowA[k] >> 5) & 0x1f;
+ const int rowBg0 = (rowB[j] >> 5) & 0x1f;
+ const int rowBg1 = (rowB[k] >> 5) & 0x1f;
+ const int rowCg0 = (rowC[j] >> 5) & 0x1f;
+ const int rowCg1 = (rowC[k] >> 5) & 0x1f;
+ const int rowDg0 = (rowD[j] >> 5) & 0x1f;
+ const int rowDg1 = (rowD[k] >> 5) & 0x1f;
+ const int rowAb0 = (rowA[j] >> 10) & 0x1f;
+ const int rowAb1 = (rowA[k] >> 10) & 0x1f;
+ const int rowBb0 = (rowB[j] >> 10) & 0x1f;
+ const int rowBb1 = (rowB[k] >> 10) & 0x1f;
+ const int rowCb0 = (rowC[j] >> 10) & 0x1f;
+ const int rowCb1 = (rowC[k] >> 10) & 0x1f;
+ const int rowDb0 = (rowD[j] >> 10) & 0x1f;
+ const int rowDb1 = (rowD[k] >> 10) & 0x1f;
+ const int rowAa0 = (rowA[j] >> 15) & 0x1;
+ const int rowAa1 = (rowA[k] >> 15) & 0x1;
+ const int rowBa0 = (rowB[j] >> 15) & 0x1;
+ const int rowBa1 = (rowB[k] >> 15) & 0x1;
+ const int rowCa0 = (rowC[j] >> 15) & 0x1;
+ const int rowCa1 = (rowC[k] >> 15) & 0x1;
+ const int rowDa0 = (rowD[j] >> 15) & 0x1;
+ const int rowDa1 = (rowD[k] >> 15) & 0x1;
+ const int r = FILTER_SUM_3D(rowAr0, rowAr1, rowBr0, rowBr1,
+ rowCr0, rowCr1, rowDr0, rowDr1);
+ const int g = FILTER_SUM_3D(rowAg0, rowAg1, rowBg0, rowBg1,
+ rowCg0, rowCg1, rowDg0, rowDg1);
+ const int b = FILTER_SUM_3D(rowAb0, rowAb1, rowBb0, rowBb1,
+ rowCb0, rowCb1, rowDb0, rowDb1);
+ const int a = FILTER_SUM_3D(rowAa0, rowAa1, rowBa0, rowBa1,
+ rowCa0, rowCa1, rowDa0, rowDa1);
+
+ dst[i] = (a << 15) | (b << 10) | (g << 5) | r;
+ }
+ }
+ else if ((datatype == DTYPE_UBYTE_3_3_2) && (comps == 3)) {
+ DECLARE_ROW_POINTERS0(ushort);
+
+ for (i = j = 0, k = k0; i < (uint) dstWidth;
+ i++, j += colStride, k += colStride) {
+ const int rowAr0 = rowA[j] & 0x3;
+ const int rowAr1 = rowA[k] & 0x3;
+ const int rowBr0 = rowB[j] & 0x3;
+ const int rowBr1 = rowB[k] & 0x3;
+ const int rowCr0 = rowC[j] & 0x3;
+ const int rowCr1 = rowC[k] & 0x3;
+ const int rowDr0 = rowD[j] & 0x3;
+ const int rowDr1 = rowD[k] & 0x3;
+ const int rowAg0 = (rowA[j] >> 2) & 0x7;
+ const int rowAg1 = (rowA[k] >> 2) & 0x7;
+ const int rowBg0 = (rowB[j] >> 2) & 0x7;
+ const int rowBg1 = (rowB[k] >> 2) & 0x7;
+ const int rowCg0 = (rowC[j] >> 2) & 0x7;
+ const int rowCg1 = (rowC[k] >> 2) & 0x7;
+ const int rowDg0 = (rowD[j] >> 2) & 0x7;
+ const int rowDg1 = (rowD[k] >> 2) & 0x7;
+ const int rowAb0 = (rowA[j] >> 5) & 0x7;
+ const int rowAb1 = (rowA[k] >> 5) & 0x7;
+ const int rowBb0 = (rowB[j] >> 5) & 0x7;
+ const int rowBb1 = (rowB[k] >> 5) & 0x7;
+ const int rowCb0 = (rowC[j] >> 5) & 0x7;
+ const int rowCb1 = (rowC[k] >> 5) & 0x7;
+ const int rowDb0 = (rowD[j] >> 5) & 0x7;
+ const int rowDb1 = (rowD[k] >> 5) & 0x7;
+ const int r = FILTER_SUM_3D(rowAr0, rowAr1, rowBr0, rowBr1,
+ rowCr0, rowCr1, rowDr0, rowDr1);
+ const int g = FILTER_SUM_3D(rowAg0, rowAg1, rowBg0, rowBg1,
+ rowCg0, rowCg1, rowDg0, rowDg1);
+ const int b = FILTER_SUM_3D(rowAb0, rowAb1, rowBb0, rowBb1,
+ rowCb0, rowCb1, rowDb0, rowDb1);
+ dst[i] = (b << 5) | (g << 2) | r;
+ }
+ }
+ else {
+ debug_printf("bad format in do_row_3D()");
+ }
+}
+
+
+