Add shapes_math_sine_cosine example

Author: midiphony

examples/shapes/shapes_math_sine_cosine.c

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+/*******************************************************************************************
+*
+*   raylib [shapes] example - math sine cosine
+*
+*   Example complexity rating: [★☆☆☆] 1/4
+*
+*   Example originally created with raylib 5.6, last time updated with raylib 5.6
+*
+*   Example contributed by Midiphony (@midiphony) and reviewed by Ramon Santamaria (@raysan5)
+*
+*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
+*   BSD-like license that allows static linking with closed source software
+*
+*   Copyright (c) 2025-2025 Zero (@zerohorsepower)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+#include "raymath.h" // Required for: Vector2 operations and Clamp()
+#include <stdlib.h> // Required for: malloc(), free()
+#include <math.h> // Required for: cosf(), sinf()
+
+//------------------------------------------------------------------------------------
+// Program main entry point
+//------------------------------------------------------------------------------------
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    const Color cosineColor = RED;
+    const Color sineColor = ORANGE;
+    const int pointsSize = 6;
+    const int lineThickness = 2;
+
+    const int screenWidth = 800;
+    const int screenHeight = 450;
+
+    // Circle
+    const int circleX = screenWidth/4 - 20;
+    const int circleY = screenHeight/2;
+    const Vector2 circlePosition = { circleX, circleY };
+    const int circleRadius = 140;
+    const int circleLeft = circleX - circleRadius;
+    const int circleRight = circleX + circleRadius;
+    const int circleTop = circleY - circleRadius;
+    const int circleBottom = circleY + circleRadius;
+
+    const int circleTextFontSize = 20;
+
+    // Graph
+    const int graphLeft = screenWidth/2;
+    const int graphRight = 750;
+    const int graphHeight = 200;
+    const int graphHalfHeight = graphHeight/2;
+    const int graphYMiddle = screenHeight/2;
+    const int graphTop = graphYMiddle - graphHalfHeight;
+    const int graphBottom = graphYMiddle + graphHalfHeight;
+    const int graphWidth = graphRight - graphLeft;
+
+    const int graphTextFontSize = 20;
+    const int graphTextPadding = 10;
+
+    Vector2* cosineCurvePoints = (Vector2*)malloc(graphWidth*sizeof(Vector2)); // Points array
+    Vector2* sineCurvePoints = (Vector2*)malloc(graphWidth*sizeof(Vector2)); // Points array
+
+    // Initialize cosine curve
+    for (int x = 0; x < graphWidth; x++)
+    {
+        float y = -cosf(((float)x/graphWidth)*2.0*PI);
+        int yCoord = graphYMiddle + y*graphHalfHeight;
+        cosineCurvePoints[x] = (Vector2){ graphLeft + x, yCoord };
+    }
+
+    // Initialize sine curve
+    for (int x = 0; x < graphWidth; x++)
+    {
+        float y = sinf(((float)x/graphWidth)*2.0*PI);
+        int yCoord = graphYMiddle - y*graphHalfHeight;
+        sineCurvePoints[x] = (Vector2){ graphLeft + x, yCoord };
+    }
+
+    const int windowSplitX = ((circleX + circleRadius) + graphLeft)/2;
+
+    InitWindow(screenWidth, screenHeight, "raylib [shapes] example - math sine cosine");
+
+    const int circleTextMaxLength = MeasureText("-1.000", circleTextFontSize);
+    const int graphTextMaxLength = MeasureText("-1.000", graphTextFontSize);
+
+    SetTargetFPS(60);
+    //--------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        Vector2 mousePosition = GetMousePosition();
+        float angleInDegrees = 0.0f;
+        float angle = 0;
+
+        if (mousePosition.x <= windowSplitX) // Calculate angle relative to the circle
+        {
+            angle = Vector2Angle(Vector2Subtract(mousePosition, circlePosition), (Vector2) { 1, 0 });
+            if (angle < 0.0f)
+            {
+                angle += 2*PI;
+            }
+        }
+        else // Calculate angle relative to the graph
+        {
+            angle = Clamp((mousePosition.x - graphLeft)*2*PI/graphWidth, 0.0f, 2*PI);
+        }
+
+        angleInDegrees = angle*RAD2DEG;
+
+        float cosine = cosf(angle);
+        float sine = sinf(angle);
+        int pointX = circleX + circleRadius*cosine;
+        int pointY = circleY - circleRadius*sine;
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+        ClearBackground(RAYWHITE);
+
+        // Draw top angle label
+        DrawText(TextFormat("Angle:%.1f", angleInDegrees), 20, 20, 30, GRAY);
+
+        // Trigonometry circle
+        // --------------------
+        DrawRing(circlePosition, circleRadius - lineThickness/2, circleRadius + lineThickness/2, 0, 360, 0, GRAY); // 0 ring segment to let DrawRing choose a number of segments giving a smooth circle
+        DrawLineEx((Vector2) { circleLeft, circleY }, (Vector2) { circleRight, circleY }, lineThickness, GRAY);
+        DrawLineEx((Vector2) { circleX, circleTop }, (Vector2) { circleX, circleBottom }, lineThickness, GRAY);
+
+        DrawCircleSectorLines(circlePosition, circleRadius/3, 0, -angleInDegrees, 0, BLUE);
+
+        // Draw line to point
+        DrawLine(circleX, circleY, pointX, pointY, GRAY);
+
+        // Draw cosine point
+        DrawLineEx((Vector2) { circleX, circleY }, (Vector2) { pointX, circleY }, lineThickness, cosineColor);
+        DrawText(TextFormat("%.3f", cosine), ((pointX + circleX)/2) - circleTextMaxLength/2, circleY + 2, circleTextFontSize, cosineColor);
+        // Draw sine point
+        DrawLineEx((Vector2) { pointX, circleY }, (Vector2) { pointX, pointY }, lineThickness, sineColor);
+        DrawText(TextFormat("%.3f", sine), pointX + 5, (pointY + circleY)/2 - circleTextFontSize/2, circleTextFontSize, sineColor);
+
+        // Draw point
+        DrawCircle(pointX, pointY, pointsSize, BLACK);
+        // --------------------
+
+        // Window split
+        DrawLine(windowSplitX, 0, windowSplitX, screenHeight - 1, GRAY);
+
+        // Graph
+        // --------------------
+        // Draw graph borders
+        DrawLineEx((Vector2) { graphLeft, graphTop }, (Vector2) { graphLeft, graphBottom }, 2, GRAY);
+        DrawLineEx((Vector2) { graphRight, graphTop }, (Vector2) { graphRight, graphBottom }, 2, GRAY);
+        DrawLineEx((Vector2) { graphLeft, graphYMiddle }, (Vector2) { graphRight, graphYMiddle }, 2, GRAY);
+
+        // Draw graph outer texts
+        DrawText("1", graphLeft - graphTextPadding - MeasureText("1", graphTextFontSize), graphTop - graphTextFontSize/2, graphTextFontSize, GRAY);
+        DrawText("0", graphLeft - graphTextPadding - MeasureText("0", graphTextFontSize), graphYMiddle - graphTextFontSize/2, graphTextFontSize, GRAY);
+        DrawText("-1", graphLeft - graphTextPadding - MeasureText("-1", graphTextFontSize), graphBottom - graphTextFontSize/2, graphTextFontSize, GRAY);
+        DrawText("0", graphLeft - MeasureText("0", graphTextFontSize)/2, graphBottom + graphTextPadding/2, graphTextFontSize, GRAY);
+        DrawText("360", graphRight - MeasureText("360", graphTextFontSize)/2, graphBottom + graphTextPadding/2, graphTextFontSize, GRAY);
+
+        // Draw cosine curve
+        DrawSplineLinear(cosineCurvePoints, graphWidth, 2, cosineColor);
+        DrawText("cos", graphRight + graphTextPadding, cosineCurvePoints[graphWidth - 1].y - graphTextFontSize/2, graphTextFontSize, cosineColor);
+
+        // Draw sine curve
+        DrawSplineLinear(sineCurvePoints, graphWidth, 2, sineColor);
+        DrawText("sin", graphRight + graphTextPadding, sineCurvePoints[graphWidth - 1].y - graphTextFontSize/2, graphTextFontSize, sineColor);
+
+        // Draw graph progress line
+        int x = graphLeft + graphWidth*angleInDegrees/360.0f;
+        DrawLine(x, graphBottom, x, graphTop, BLUE);
+
+        // Draw cosine and sine points on graph
+        int cosineY = graphYMiddle - cosine*graphHalfHeight;
+        int sineY = graphYMiddle - sine*graphHalfHeight;
+        DrawCircle(x, cosineY, pointsSize, cosineColor);
+        DrawText(TextFormat("%.3f", cosine), x - circleTextMaxLength/2, cosineY - circleTextFontSize - 5, circleTextFontSize, cosineColor);
+        DrawCircle(x, sineY, pointsSize, sineColor);
+        DrawText(TextFormat("%.3f", sine), x - circleTextMaxLength/2, sineY + 8, circleTextFontSize, sineColor);
+        // --------------------
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+
+    free(cosineCurvePoints);
+    free(sineCurvePoints);
+
+    CloseWindow();        // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}