Fix flow output after we did normalization in the add step.

diff --git a/flow.cpp b/flow.cpp
index 11f4d4c87646ba31d5c9d2c485386f848c6613d1..06d29d847325fe9d7283c198132939d2297abe5f 100644 (file)
--- a/flow.cpp
+++ b/flow.cpp
@@ -997,8 +997,8 @@ int main(void)
 
        int level_width = WIDTH >> finest_level;
        int level_height = HEIGHT >> finest_level;
-       unique_ptr<float[]> dense_flow(new float[level_width * level_height * 3]);
-       glGetTextureImage(prev_level_flow_tex, 0, GL_RGB, GL_FLOAT, level_width * level_height * 3 * sizeof(float), dense_flow.get());
+       unique_ptr<float[]> dense_flow(new float[level_width * level_height * 2]);
+       glGetTextureImage(prev_level_flow_tex, 0, GL_RG, GL_FLOAT, level_width * level_height * 2 * sizeof(float), dense_flow.get());
 
        FILE *fp = fopen("flow.ppm", "wb");
        FILE *flowfp = fopen("flow.flo", "wb");
@@ -1009,12 +1009,11 @@ int main(void)
        for (unsigned y = 0; y < unsigned(level_height); ++y) {
                int yy = level_height - y - 1;
                for (unsigned x = 0; x < unsigned(level_width); ++x) {
-                       float du = dense_flow[(yy * level_width + x) * 3 + 0];
-                       float dv = dense_flow[(yy * level_width + x) * 3 + 1];
-                       float w = dense_flow[(yy * level_width + x) * 3 + 2];
+                       float du = dense_flow[(yy * level_width + x) * 2 + 0];
+                       float dv = dense_flow[(yy * level_width + x) * 2 + 1];
 
-                       du = (du / w) * level_width;
-                       dv = (-dv / w) * level_height;
+                       du = du * level_width;
+                       dv = -dv * level_height;
 
                        fwrite(&du, 4, 1, flowfp);
                        fwrite(&dv, 4, 1, flowfp);