/* See LICENSE file for copyright and license details. */
#include "common.h"
static void
multiply_33(double **outputs, size_t opos, const double **inputs, size_t ipos, const double matrix[3][3])
{
double i0 = inputs[0][ipos], i1 = inputs[1][ipos], i2 = inputs[2][ipos];
outputs[0][opos] = i0 * matrix[0][0] + i1 * matrix[1][0] + i2 * matrix[2][0];
outputs[1][opos] = i0 * matrix[0][1] + i1 * matrix[1][1] + i2 * matrix[2][1];
outputs[2][opos] = i0 * matrix[0][2] + i1 * matrix[1][2] + i2 * matrix[2][2];
}
static void
multiply_nn(size_t n, double **outputs, size_t opos, const double **inputs, size_t ipos,
const double matrix[n][n], double buffer[n])
{
size_t i, j;
for (j = 0; j < n; j++)
buffer[j] = inputs[j][ipos];
for (i = 0; i < n; i++) {
outputs[i][opos] = buffer[0] * matrix[0][i];
for (j = 1; j < n; j++)
outputs[i][opos] += buffer[j] * matrix[j][i];
}
}
static void
multiply_nm(size_t n, size_t m, double **outputs /* m */, size_t opos, const double **inputs /* n */,
size_t ipos, const double matrix[n][m], double buffer[n])
{
size_t i, j;
for (j = 0; j < n; j++)
buffer[j] = inputs[j][ipos];
for (i = 0; i < m; i++) {
outputs[i][opos] = buffer[0] * matrix[0][i];
for (j = 1; j < n; j++)
outputs[i][opos] += buffer[j] * matrix[j][i];
}
}
void
libglitter_colour_space_convert_rasters_double(size_t n, size_t m, double **outputs /* m */, const double **inputs /* n */,
size_t output_rowsize, size_t output_cellsize, size_t input_rowsize,
size_t input_cellsize, size_t width, size_t height, const double matrix[n][m])
{
size_t y, x, output_i, input_i, output_blanking, input_blanking;
double *buffer;
output_blanking = (output_rowsize - width) * output_cellsize;
input_blanking = (input_rowsize - width) * input_cellsize;
output_i = 0;
input_i = 0;
if (n == 3 && m == 3) {
for (y = 0; y < height; y++, output_i += output_blanking, input_i += input_blanking)
for (x = 0; x < width; x++, output_i += output_cellsize, input_i += input_cellsize)
multiply_33(outputs, output_i, inputs, input_i, matrix);
} else if (n == m) {
buffer = alloca(n * sizeof(*buffer));
for (y = 0; y < height; y++, output_i += output_blanking, input_i += input_blanking)
for (x = 0; x < width; x++, output_i += output_cellsize, input_i += input_cellsize)
multiply_nn(n, outputs, output_i, inputs, input_i, matrix, buffer);
} else {
buffer = alloca(n * sizeof(*buffer));
for (y = 0; y < height; y++, output_i += output_blanking, input_i += input_blanking)
for (x = 0; x < width; x++, output_i += output_cellsize, input_i += input_cellsize)
multiply_nm(n, m, outputs, output_i, inputs, input_i, matrix, buffer);
}
}
