Digitize the line with endpoints (2,2) and (10,5) using DDA
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The Digital Differential Analyzer (DDA) algorithm is used to rasterize lines in computer graphics, converting a line from continuous coordinates to discrete pixels on a raster grid. Here’s how you can use the DDA algorithm to digitize the line with endpoints (2,2) and (10,5):
### **Steps for DDA Algorithm**
1. **Calculate Line Parameters**:
- Determine the differences in x and y coordinates between the endpoints.
- Compute the number of steps required to draw the line, which is based on the larger of the differences in x or y coordinates.
2. **Calculate Increment Values**:
- Compute the increments for x and y coordinates based on the number of steps.
3. **Iterate and Plot Points**:
- Start at the initial point and incrementally plot the next points according to the calculated increments.
### **Detailed Calculation**
**1. Calculate Line Parameters**
- **Endpoints**: (x0, y0) = (2, 2) and (x1, y1) = (10, 5)
- **Δx (change in x)**: x1 - x0 = 10 - 2 = 8
- **Δy (change in y)**: y1 - y0 = 5 - 2 = 3
**2. Compute Number of Steps**
The number of steps is the maximum of the absolute values of Δx and Δy:
- **Steps**: max(|Δx|, |Δy|) = max(8, 3) = 8
**3. Calculate Increment Values**
- **Increment for x**: Δx / steps = 8 / 8 = 1
- **Increment for y**: Δy / steps = 3 / 8 = 0.375
**4. Iteration and Plotting**
Start at (x0, y0) = (2, 2). For each step, calculate the next point by adding the increments and round to the nearest integer for pixel positions:
- **Initial Point**: (x, y) = (2, 2)
**For each step**:
x = x + increment_x
y = y + increment_y
Let’s calculate the points for each step:
1. **Step 0**:
x = 2 + (0 * 1) = 2
y = 2 + (0 * 0.375) = 2
- **Plot**: (2, 2)
2. **Step 1**:
x = 2 + (1 * 1) = 3
y = 2 + (1 * 0.375) = 2.375
- **Plot**: (3, 2)
3. **Step 2**:
x = 2 + (2 * 1) = 4
y = 2 + (2 * 0.375) = 2.75
- **Plot**: (4, 3)
4. **Step 3**:
x = 2 + (3 * 1) = 5
y = 2 + (3 * 0.375) = 3.125
- **Plot**: (5, 3)
5. **Step 4**:
x = 2 + (4 * 1) = 6
y = 2 + (4 * 0.375) = 3.5
- **Plot**: (6, 4)
6. **Step 5**:
x = 2 + (5 * 1) = 7
y = 2 + (5 * 0.375) = 3.875
- **Plot**: (7, 4)
7. **Step 6**:
x = 2 + (6 * 1) = 8
y = 2 + (6 * 0.375) = 4.25
- **Plot**: (8, 4)
8. **Step 7**:
x = 2 + (7 * 1) = 9
y = 2 + (7 * 0.375) = 4.625
- **Plot**: (9, 5)
9. **Step 8**:
x = 2 + (8 * 1) = 10
y = 2 + (8 * 0.375) = 5
- **Plot**: (10, 5)
### **Summary of Points**
Using the DDA algorithm, the points to plot for the line from (2, 2) to (10, 5) are approximately:
(2, 2)
(3, 2)
(4, 3)
(5, 3)
(6, 4)
(7, 4)
(8, 4)
(9, 5)
(10, 5)
These points represent the discrete pixels that form the line on a raster grid, effectively digitizing the continuous line segment.
Hope you got this.