implement mapping table
Stefan Schuermans commited on 2017-06-11 13:35:25
Showing 2 changed files, with 45 additions and 0 deletions.
- simulator/mapping.cpp 9f52a9f..6146464
- simulator/mapping.h 5ca547f..69b3252
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@@ -17,6 +17,9 @@ |
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* along with this program. If not, see <http://www.gnu.org/licenses/>. |
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*/ |
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+#include <math.h> |
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+#include <stdint.h> |
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+ |
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#include "mapping.h" |
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/// default constructor |
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@@ -25,6 +28,7 @@ Mapping::Mapping(): |
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m_factor(0.0), |
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m_gamma(1.0) |
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{
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+ update(); |
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} |
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/// constructor based on parameters |
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@@ -33,5 +37,31 @@ Mapping::Mapping(double base, double factor, double gamma): |
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m_factor(factor), |
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m_gamma(gamma) |
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{
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+ update(); |
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+} |
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+ |
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+/// update internal mapping table based on parameters |
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+void Mapping::update() |
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+{
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+ /* mapping formula: |
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+ * display := base + factor * video ** (1.0 / gamma) |
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+ * display values are coming in via IPv4/UDP |
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+ * simulator needs to show video values |
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+ * video := ((display - base) / factor) ** gamma |
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+ */ |
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+ for (unsigned int display_i = 0; display_i < 256; ++display_i) {
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+ double display = (double)display_i / 255.0; |
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+ double video = pow((display - m_base) / m_factor, m_gamma); |
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+ uint8_t video_u8; |
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+ if (video < 0.0) {
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+ video_u8 = 0; |
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+ } else if (video > 1.0) {
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+ video_u8 = 255; |
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+ } else {
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+ video_u8 = (uint8_t)round(255.0 * video); |
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+ } |
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+ m_display2video[display_i] = video_u8; |
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} |
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+} |
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+ |
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@@ -20,6 +20,8 @@ |
| 20 | 20 |
#ifndef MAPPING_H |
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#define MAPPING_H |
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+#include <stdint.h> |
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+ |
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/// mapping of input values to LED output values for a color channel |
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class Mapping |
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{
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@@ -39,6 +41,16 @@ public: |
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/// constructor based on parameters |
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Mapping(double base, double factor, double gamma); |
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+ /// map display value to video value |
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+ uint8_t display2video(uint8_t display) const |
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+ {
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+ return m_display2video[display]; |
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+ } |
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+ |
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+protected: |
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+ /// update internal mapping table based on parameters |
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+ void update(); |
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+ |
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protected: |
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/// parameters of mapping: display := base + factor * video ** (1.0 / gamma) |
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//@{
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@@ -46,6 +58,9 @@ protected: |
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double m_factor; |
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double m_gamma; |
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//@} |
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+ /** mapping table from display values (from IPv4/UDP) |
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+ to video values (to show on screen) */ |
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+ uint8_t m_display2video[256]; |
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}; |
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#endif // #ifndef MAPPING_H |
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