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| #include <GL/freeglut.h>
#include <string>
#define _USE_MATH_DEFINES
#include <math.h>
// Hide the console
#pragma comment(linker, "/SUBSYSTEM:windows /ENTRY:mainCRTStartup")
const float M_PI_F = (float)M_PI;
const float g_fieldWidth = 4 * M_PI_F;
const float g_fieldHeight = 4;
const float g_halfFieldWidth = g_fieldWidth / 2;
const float g_halfFieldHeight = g_fieldHeight / 2;
const float g_onePercentOfHalfWidth = (float)g_halfFieldWidth / 100;
const float g_onePercentOfHalfHeight = (float)g_halfFieldHeight / 100;
void drawText(float x, float y, std::string text, float r, float g, float b)
{
glColor3f(r, g, b);
glRasterPos2f(x, y);
glutBitmapString(GLUT_BITMAP_8_BY_13, (const unsigned char*)text.c_str());
}
void drawLine(
float x0, float y0, float x1, float y1,
float r, float g, float b)
{
glColor3f(r, g, b);
glBegin(GL_LINES);
{
glVertex2f(x0, y0);
glVertex2f(x1, y1);
}
glEnd();
}
void drawSin(float r, float g, float b)
{
const float step = (float)M_PI / 10;
float xPrev = -2 * (float)M_PI;
for (size_t i = 0; i < 40; i++)
{
float x0 = xPrev;
float y0 = sin(x0);
float x1 = x0 + step;
float y1 = sin(x1);
xPrev = x1;
drawLine(x0, y0, x1, y1, r, g, b);
}
}
void drawCoordinates(float r, float g, float b)
{
float halfOfLengthOfLine = 4;
// 1
drawText(-14 * g_onePercentOfHalfWidth, g_halfFieldHeight / 2, "1", r, g, b);
drawLine(
-halfOfLengthOfLine * g_onePercentOfHalfWidth,
g_halfFieldHeight / 2,
halfOfLengthOfLine * g_onePercentOfHalfWidth,
g_halfFieldHeight / 2, r, g, b);
// -1
drawText(-18 * g_onePercentOfHalfWidth, -g_halfFieldHeight / 2, "-1", r, g, b);
drawLine(
-halfOfLengthOfLine * g_onePercentOfHalfWidth,
-g_halfFieldHeight / 2, 2 * g_onePercentOfHalfWidth,
-g_halfFieldHeight / 2, r, g, b);
// Pi
drawText(
M_PI_F - 5 * g_onePercentOfHalfWidth,
7 * g_onePercentOfHalfHeight, "Pi", r, g, b);
drawLine(
M_PI_F, -halfOfLengthOfLine * g_onePercentOfHalfHeight,
M_PI_F, halfOfLengthOfLine * g_onePercentOfHalfHeight,
r, g, b);
// -Pi
drawText(
-M_PI_F - 7 * g_onePercentOfHalfWidth,
7 * g_onePercentOfHalfHeight, "-Pi", r, g, b);
drawLine(
-M_PI_F, -halfOfLengthOfLine * g_onePercentOfHalfHeight,
-M_PI_F, halfOfLengthOfLine * g_onePercentOfHalfHeight,
r, g, b);
}
void draw()
{
glClear(GL_COLOR_BUFFER_BIT);
drawText(
g_halfFieldWidth - 80 * g_onePercentOfHalfWidth,
g_halfFieldHeight - 20 * g_onePercentOfHalfHeight,
"y = Sin(x)", 1, 1, 1);
// X
drawLine(-g_halfFieldWidth, 0, g_halfFieldWidth, 0, 1, 0, 0);
drawText(
g_halfFieldWidth - 10 * g_onePercentOfHalfWidth,
-10 * g_onePercentOfHalfHeight, "X", 1, 0, 0);
// Y
drawLine(0, -g_halfFieldHeight, 0, g_halfFieldHeight, 0, 1, 0);
drawText(
-10 * g_onePercentOfHalfWidth,
g_halfFieldHeight - 15 * g_onePercentOfHalfHeight, "Y", 0, 1, 0);
drawCoordinates(1, 1, 1);
drawSin(0.5, 0.5, 1);
glutSwapBuffers();
}
void setup2DGraphics(double width, double height)
{
double halfWidth = width / 2;
double halfHeight = height / 2;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-halfWidth, halfWidth, -halfHeight, halfHeight, 100, -100);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
glutInitWindowSize(256, 256);
glutCreateWindow("Sin");
setup2DGraphics(g_fieldWidth, g_fieldHeight);
glutDisplayFunc(draw);
glutMainLoop();
return 0;
} |
Сообщение от Ений_В
