private void CalcCoordsAndUpdate(ColourHandler.HSV HSV) { // Convert color to real-world coordinates and then calculate // the various points. HSV.Hue represents the degrees (0 to 360), // HSV.Saturation represents the radius. // This procedure doesn't draw anything--it simply // updates class-level variables. The UpdateDisplay // procedure uses these values to update the screen. // Given the angle (HSV.Hue), and distance from // the center (HSV.Saturation), and the center, // calculate the point corresponding to // the selected color, on the color wheel. colourPoint = GetPoint((double)HSV.Hue / 255 * 360, (double)HSV.Saturation / 255 * radius, centerPoint); // Given the brightness (HSV.value), calculate the // point corresponding to the brightness indicator. brightnessPoint = CalcBrightnessPoint(HSV.value); // Store information about the selected color. brightness = HSV.value; selectedColour = ColourHandler.HSVtoColour(HSV); RGB = ColourHandler.HSVtoRGB(HSV); // The full color is the same as HSV, except that the // brightness is set to full (255). This is the top-most // color in the brightness gradient. fullColour = ColourHandler.HSVtoColour(HSV.Hue, HSV.Saturation, 255); }
private Color[] GetColours() { // Create an array of COLOR_COUNT // colors, looping through all the // hues between 0 and 255, broken // into COLOR_COUNT intervals. HSV is // particularly well-suited for this, // because the only value that changes // as you create colors is the Hue. Color[] Colours = new Color[COLOUR_COUNT]; for (int i = 0; i <= COLOUR_COUNT - 1; i++) { Colours[i] = ColourHandler.HSVtoColour((int)((double)(i * 255) / COLOUR_COUNT), 255, 255); } return(Colours); }
public void Draw(Graphics g, Point mousePoint) { // You've moved the mouse. // Now update the screen to match. double distance; int degrees; Point delta; Point newColourPoint; Point newBrightnessPoint; Point newPoint; // Keep track of the previous color pointer point, // so you can put the mouse there in case the // user has clicked outside the circle. newColourPoint = colourPoint; newBrightnessPoint = brightnessPoint; // Store this away for later use. this.g = g; if (currentState == MouseState.MouseUp) { if (!mousePoint.IsEmpty) { if (colourRegion.IsVisible(mousePoint)) { // Is the mouse point within the color circle? // If so, you just clicked on the color wheel. currentState = MouseState.ClickOnColor; } else if (brightnessRegion.IsVisible(mousePoint)) { // Is the mouse point within the brightness area? // You clicked on the brightness area. currentState = MouseState.ClickOnBrightness; } else { // Clicked outside the color and the brightness // regions. In that case, just put the // pointers back where they were. currentState = MouseState.ClickOutsideRegion; } } } switch (currentState) { case MouseState.ClickOnBrightness: case MouseState.DragInBrightness: // Calculate new color information // based on the brightness, which may have changed. newPoint = mousePoint; if (newPoint.Y < brightnessMin) { newPoint.Y = brightnessMin; } else if (newPoint.Y > brightnessMax) { newPoint.Y = brightnessMax; } newBrightnessPoint = new Point(brightnessX, newPoint.Y); brightness = (int)((brightnessMax - newPoint.Y) * brightnessScaling); HSV.value = brightness; RGB = ColourHandler.HSVtoRGB(HSV); break; case MouseState.ClickOnColor: case MouseState.DragInColor: // Calculate new color information // based on selected color, which may have changed. newColourPoint = mousePoint; // Calculate x and y distance from the center, // and then calculate the angle corresponding to the // new location. delta = new Point( mousePoint.X - centerPoint.X, mousePoint.Y - centerPoint.Y); degrees = CalcDegrees(delta); // Calculate distance from the center to the new point // as a fraction of the radius. Use your old friend, // the Pythagorean theorem, to calculate this value. distance = Math.Sqrt(delta.X * delta.X + delta.Y * delta.Y) / radius; if (currentState == MouseState.DragInColor) { if (distance > 1) { // Mouse is down, and outside the circle, but you // were previously dragging in the color circle. // What to do? // In that case, move the point to the edge of the // circle at the correct angle. distance = 1; newColourPoint = GetPoint(degrees, radius, centerPoint); } } // Calculate the new HSV and RGB values. HSV.Hue = (int)(degrees * 255 / 360); HSV.Saturation = (int)(distance * 255); HSV.value = brightness; RGB = ColourHandler.HSVtoRGB(HSV); fullColour = ColourHandler.HSVtoColour(HSV.Hue, HSV.Saturation, 255); break; } selectedColour = ColourHandler.HSVtoColour(HSV); // Raise an event back to the parent form, // so the form can update any UI it's using // to display selected color values. OnColourChanged(RGB, HSV); // On the way out, set the new state. switch (currentState) { case MouseState.ClickOnBrightness: currentState = MouseState.DragInBrightness; break; case MouseState.ClickOnColor: currentState = MouseState.DragInColor; break; case MouseState.ClickOutsideRegion: currentState = MouseState.DragOutsideRegion; break; } // Store away the current points for next time. colourPoint = newColourPoint; brightnessPoint = newBrightnessPoint; // Draw the gradients and points. UpdateDisplay(); }