diff --git a/stb_resample.h b/stb_resample.h index b7b1680..41bc138 100644 --- a/stb_resample.h +++ b/stb_resample.h @@ -18,10 +18,11 @@ Initial implementation by Jorge L Rodriguez #define STBR_INCLUDE_STB_RESAMPLE_H // Basic usage: -// result = stbr_resize(input_data, input_w, input_h, input_components, output_data, output_w, output_h, STBR_FILTER_NEAREST, STBR_EDGE_CLAMP); +// result = stbr_resize(input_data, input_w, input_h, input_components, 0, output_data, output_w, output_h, 0, STBR_FILTER_NEAREST, STBR_EDGE_CLAMP); // // input_data is your supplied texels. -// output_data will be the resized texels. It should be of size output_w * output_h * input_components. +// output_data will be the resized texels. It should be of size output_w * output_h * input_components (or output_h * output_stride if you provided a stride.) +// If input_stride or output_stride is 0 (as in this example) the stride will be automatically calculated as width*components. // Returned result is 1 for success or 0 in case of an error. typedef enum @@ -52,7 +53,7 @@ extern "C" { // PRIMARY API - resize an image // - STBRDEF int stbr_resize(const stbr_uc* input_data, int input_w, int input_h, int input_components, stbr_uc* output_data, int output_w, int output_h, stbr_filter filter, stbr_edge edge); + STBRDEF int stbr_resize(const stbr_uc* input_data, int input_w, int input_h, int input_components, int input_stride, stbr_uc* output_data, int output_w, int output_h, int output_stride, stbr_filter filter, stbr_edge edge); #ifdef __cplusplus @@ -159,17 +160,18 @@ static void stbr__filter_nearest_n(const stbr_uc* input_data, stbr_uc* output_da typedef void (stbr__filter_fn)(const stbr_uc* input_data, stbr_uc* output_data, size_t input_texel_index, size_t output_texel_index, size_t n); -STBRDEF int stbr_resize(const stbr_uc* input_data, int input_w, int input_h, int input_components, stbr_uc* output_data, int output_w, int output_h, stbr_filter filter, stbr_edge edge) +STBRDEF int stbr_resize(const stbr_uc* input_data, int input_w, int input_h, int input_components, int input_stride, stbr_uc* output_data, int output_w, int output_h, int output_stride, stbr_filter filter, stbr_edge edge) { int x, y; - int width_stride_input = input_components * input_w; - int width_stride_output = input_components * output_w; + int width_stride_input = input_stride ? input_stride : input_components * input_w; + int width_stride_output = output_stride ? output_stride : input_components * output_w; #ifdef STBR_DEBUG_OVERWRITE_TEST #define OVERWRITE_ARRAY_SIZE 64 unsigned char overwrite_contents_pre[OVERWRITE_ARRAY_SIZE]; - memcpy(overwrite_contents_pre, &output_data[output_w * output_h * input_components], OVERWRITE_ARRAY_SIZE); + size_t begin_forbidden = width_stride_output * (output_h - 1) + output_w * input_components; + memcpy(overwrite_contents_pre, &output_data[begin_forbidden], OVERWRITE_ARRAY_SIZE); #endif if (filter == STBR_FILTER_NEAREST) @@ -203,7 +205,7 @@ STBRDEF int stbr_resize(const stbr_uc* input_data, int input_w, int input_h, int return 0; #ifdef STBR_DEBUG_OVERWRITE_TEST - STBR_ASSERT(memcmp(overwrite_contents_pre, &output_data[output_w * output_h * input_components], OVERWRITE_ARRAY_SIZE) == 0); + STBR_ASSERT(memcmp(overwrite_contents_pre, &output_data[begin_forbidden], OVERWRITE_ARRAY_SIZE) == 0); #endif return 1; diff --git a/tests/resample_test.c b/tests/resample_test.c index 2c775c6..276292c 100644 --- a/tests/resample_test.c +++ b/tests/resample_test.c @@ -19,7 +19,7 @@ int main(int argc, char** argv) unsigned char* output_data; int w, h; int n; - int out_w, out_h; + int out_w, out_h, out_stride; if (argc <= 1) { @@ -36,12 +36,14 @@ int main(int argc, char** argv) out_w = 512; out_h = 512; + out_stride = (out_w + 10) * n; - output_data = malloc(out_w * out_h * n); + output_data = malloc(out_stride * out_h); - stbr_resize(input_data, w, h, n, output_data, out_w, out_h, STBR_FILTER_NEAREST, STBR_EDGE_CLAMP); + // Cut out the outside 64 pixels all around to test the stride. + stbr_resize(input_data + w*64*n + 64*n, w - 128, h - 128, n, w*n, output_data, out_w, out_h, out_stride, STBR_FILTER_NEAREST, STBR_EDGE_CLAMP); - stbi_write_png("output.png", out_w, out_h, n, output_data, out_w * n); + stbi_write_png("output.png", out_w, out_h, n, output_data, out_stride); free(output_data);