Use the aaav2 code in libmegapixels

src/process_pipeline.c

@@ -418,20 +418,38 @@ process_image_for_preview(const uint8_t *image)
                 uint32_t *center = g_malloc_n(width * height * sizeof(uint32_t), 1);
                 glReadPixels(
                         0, height, width, height, GL_RGBA, GL_UNSIGNED_BYTE, center);
+
+                libmegapixels_aaa_set_matrix(&state_proc.stats,
+                                             state_proc.calibration.color_matrix_1,
+                                             state_proc.calibration.color_matrix_2);
                 libmegapixels_aaa_software_statistics(
-                        center, width, height, &state_proc.stats);
-
-                float w_gain = 0.02f;
-                float t_gain = 0.01f;
-                state_proc.red += (state_proc.stats.temp * +w_gain) +
-                                  (state_proc.stats.tint * t_gain);
-                state_proc.blue += (state_proc.stats.temp * -w_gain) +
-                                   (state_proc.stats.tint * t_gain);
-                state_proc.blacklevel -= state_proc.stats.blacklevel * 0.001f;
+                        &state_proc.stats, center, width, height);
+
+                state_proc.blacklevel -= (float)state_proc.stats.blacklevel * 0.001f;
                 state_proc.blacklevel =
                         clamp_float(state_proc.blacklevel, 0.0f, 0.07f);
-                state_proc.red = clamp_float(state_proc.red, 0.5f, 3.0f);
-                state_proc.blue = clamp_float(state_proc.blue, 0.5f, 3.0f);
+
+                float r = state_proc.stats.avg_r;
+                float g = state_proc.stats.avg_g;
+                float b = state_proc.stats.avg_b;
+
+                // Revert the current gains set on the preview
+                b /= state_proc.red;
+                b /= state_proc.blue;
+
+                float t = 2.0f;
+                if (r < t && g < t && b < t) {
+                        // Don't try to AWB on very dark frames
+                } else {
+                        // Calculate the new R/B gains based on the average color of
+                        // the frame
+                        float new_r = g / clamp_float(r, 1.0f, 999.0f);
+                        float new_b = g / clamp_float(b, 1.0f, 999.0f);
+
+                        state_proc.red = clamp_float(new_r, 0.01f, 4.0f);
+                        state_proc.blue = clamp_float(new_b, 0.01f, 4.0f);
+                }
+
                 gles2_debayer_set_shading(gles2_debayer,
                                           state_proc.red,
                                           state_proc.blue,