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November 5, 2018 03:57
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lineutil
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| #ifndef LINEUTIL_H | |
| #define LINEUTIL_H | |
| #include "common.h" | |
| /* | |
| ** Draws horizontal line | |
| ** hexRgb = e.g. 0xFF0000 | |
| */ | |
| void drawHLine(int x1, int x2, int y, GLubyte *data, unsigned long hexRgb, int width, int height) | |
| { | |
| GLubyte red, green, blue; | |
| red = hexRgb >> 16; | |
| green = (hexRgb & 0x00ff00) >> 8; | |
| blue = (hexRgb & 0x0000ff); | |
| //Make sure Y-value is legit | |
| if (y >= 0 && y < height) { | |
| //Make sure x1 < x2 | |
| if (x2 < x1) { | |
| int tmp = x1; | |
| x1 = x2; | |
| x2 = tmp; | |
| } | |
| //Make sure at least part of the line is inside the height*width area | |
| if (!(x1 < 0 && x2 < 0) && !(x1 > width - 1 && x2 > width - 1)) { | |
| //Clamp right adn left edge values | |
| if (x1 < 0) { | |
| x1 = 0; | |
| } | |
| if (x2 > width-1) { | |
| x2 = width-1; | |
| } | |
| //render the line | |
| GLubyte* ptr = &data[(y * width + x1) * BYTES_PER_COLOR]; | |
| GLubyte* end = &data[(y * width + x2 + 1) * BYTES_PER_COLOR]; | |
| while (ptr < end) { | |
| *ptr++ = red; | |
| *ptr++ = green; | |
| *ptr++ = blue; | |
| *ptr++ = 0xFF; | |
| } | |
| } | |
| } | |
| } | |
| /* | |
| ** Draws vertical line | |
| ** hexRgb = e.g. 0xFF0000 | |
| */ | |
| void drawVLine(int x1, int y1, int y2, GLubyte *data, unsigned long hexRgb, int width, int height) | |
| { | |
| GLubyte red, green, blue; | |
| red = hexRgb >> 16; | |
| green = (hexRgb & 0x00ff00) >> 8; | |
| blue = (hexRgb & 0x0000ff); | |
| //Make sure the line is legit | |
| if (x1 >= 0 && x1 < width) { | |
| //Make sure y1 < y2 | |
| if (y1 > y2) { | |
| int tmp = y1; | |
| y1 = y2; | |
| y2 = tmp; | |
| } | |
| //Make sure part of the line is in the image area | |
| if (!(y1 < 0 && y2 < 0) && !(y1 > height - 1 && y2 > height - 1)) { | |
| //clamp values vertically | |
| if (y1 < 0) { | |
| y1 = 0; | |
| } | |
| if (y2 > height - 1) { | |
| y2 = height - 1; | |
| } | |
| //render | |
| GLubyte *ptr = &data[(y1 * width + x1) * BYTES_PER_COLOR]; | |
| int height = y2 - y1 + 1; | |
| for (int i = 0; i < height; i++) { | |
| *ptr++ = red; | |
| *ptr++ = green; | |
| *ptr++ = blue; | |
| *ptr++ = 0xFF; | |
| ptr += (BYTES_PER_COLOR * width - BYTES_PER_COLOR); | |
| } | |
| } | |
| } | |
| } | |
| #endif // LINEUTIL_H |
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