Visualize the flow consistently with .flo files (which have y = down).

[nageru] / flow.cpp

diff --git a/flow.cpp b/flow.cpp
index dba6607b0eb3e967fcb2786bd31c5051ad72797a..205b24f098e4035f9f725a2f16e0c8b493fe6289 100644 (file)
--- a/flow.cpp
+++ b/flow.cpp
@@ -16,6 +16,8 @@
 #include <assert.h>
 #include <stdio.h>
 
+#include "flow2rgb.h"
+
 #include <algorithm>
 #include <memory>
 
@@ -248,8 +250,8 @@ void Sobel::exec(GLint tex0_view, GLint grad0_tex, int level_width, int level_he
        glBindTextureUnit(0, tex0_view);
        glBindSampler(0, nearest_sampler);
        glProgramUniform1i(sobel_program, glGetUniformLocation(sobel_program, "tex"), 0);
-       glProgramUniform1f(sobel_program, glGetUniformLocation(sobel_program, "inv_width"), 1.0f / level_width);
-       glProgramUniform1f(sobel_program, glGetUniformLocation(sobel_program, "inv_height"), 1.0f / level_height);
+       glProgramUniform2f(sobel_program, glGetUniformLocation(sobel_program, "image_size"), level_width, level_height);
+       glProgramUniform2f(sobel_program, glGetUniformLocation(sobel_program, "inv_image_size"), 1.0f / level_width, 1.0f / level_height);
 
        GLuint grad0_fbo;  // TODO: cleanup
        glCreateFramebuffers(1, &grad0_fbo);
@@ -305,10 +307,8 @@ void MotionSearch::exec(GLuint tex0_view, GLuint tex1_view, GLuint grad0_tex, GL
        bind_sampler(motion_search_program, "grad0_tex", 2, grad0_tex, nearest_sampler);
        bind_sampler(motion_search_program, "flow_tex", 3, flow_tex, linear_sampler);
 
-       glProgramUniform1f(motion_search_program, glGetUniformLocation(motion_search_program, "image_width"), level_width);
-       glProgramUniform1f(motion_search_program, glGetUniformLocation(motion_search_program, "image_height"), level_height);
-       glProgramUniform1f(motion_search_program, glGetUniformLocation(motion_search_program, "inv_image_width"), 1.0f / level_width);
-       glProgramUniform1f(motion_search_program, glGetUniformLocation(motion_search_program, "inv_image_height"), 1.0f / level_height);
+       glProgramUniform2f(motion_search_program, glGetUniformLocation(motion_search_program, "image_size"), level_width, level_height);
+       glProgramUniform2f(motion_search_program, glGetUniformLocation(motion_search_program, "inv_image_size"), 1.0f / level_width, 1.0f / level_height);
 
        GLuint flow_fbo;  // TODO: cleanup
        glCreateFramebuffers(1, &flow_fbo);
@@ -494,7 +494,7 @@ int main(void)
 
                // Densification.
 
-               // Set up an output texture.
+               // Set up an output texture (initially zero).
                GLuint dense_flow_tex;
                glCreateTextures(GL_TEXTURE_2D, 1, &dense_flow_tex);
                //glTextureStorage2D(dense_flow_tex, 1, GL_RGB16F, level_width, level_height);
@@ -522,40 +522,14 @@ int main(void)
                        float dv = dense_flow[(yy * level_width + x) * 3 + 1];
                        float w = dense_flow[(yy * level_width + x) * 3 + 2];
 
-                       du /= w;
-                       dv /= w;
-
-                       float angle = atan2(dv * level_width, du * level_height);
-                       float magnitude = min(hypot(du * level_width, dv * level_height) / 20.0, 1.0);
-                       
-                       // HSV to RGB (from Wikipedia). Saturation is 1.
-                       float c = magnitude;
-                       float h = (angle + M_PI) * 6.0 / (2.0 * M_PI);
-                       float X = c * (1.0 - fabs(fmod(h, 2.0) - 1.0));
-                       float r = 0.0f, g = 0.0f, b = 0.0f;
-                       if (h < 1.0f) {
-                               r = c; g = X;
-                       } else if (h < 2.0f) {
-                               r = X; g = c;
-                       } else if (h < 3.0f) {
-                               g = c; b = X;
-                       } else if (h < 4.0f) {
-                               g = X; b = c;
-                       } else if (h < 5.0f) {
-                               r = X; b = c;
-                       } else if (h < 6.0f) {
-                               r = c; b = X;
-                       } else {
-                               // h is NaN, so black is fine.
-                       }
-                       float m = magnitude - c;
-                       r += m; g += m; b += m;
-                       r = max(min(r, 1.0f), 0.0f);
-                       g = max(min(g, 1.0f), 0.0f);
-                       b = max(min(b, 1.0f), 0.0f);
-                       putc(lrintf(r * 255.0f), fp);
-                       putc(lrintf(g * 255.0f), fp);
-                       putc(lrintf(b * 255.0f), fp);
+                       du = (du / w) * level_width;
+                       dv = (-dv / w) * level_height;
+
+                       uint8_t r, g, b;
+                       flow2rgb(du, dv, &r, &g, &b);
+                       putc(r, fp);
+                       putc(g, fp);
+                       putc(b, fp);
                }
        }
        fclose(fp);