Add easings example

examples/core/easings_example.c

@@ -0,0 +1,354 @@
+/*******************************************************************************************
+*
+*   raylib [easings] example
+*
+*   This example has been created using raylib 2.5 (www.raylib.com)
+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
+*
+*   Copyright (c) 2019 Juan Miguel López
+*
+********************************************************************************************/
+
+
+#include <raylib.h>
+#include "easings.h"
+
+
+// Application constants
+#define SCR_WIDTH 800
+#define SCR_HEIGHT 450
+#define BALL_RADIUS 16.0f
+#define BALL_COLOR MAROON
+#define PAD 80.0f
+#define START_X (0.0f + (BALL_RADIUS) + (PAD))
+#define END_X ((SCR_WIDTH) - ((BALL_RADIUS) + (PAD)))
+#define START_Y (0.0f + (BALL_RADIUS) + (PAD))
+#define END_Y ((SCR_HEIGHT) - ((BALL_RADIUS) + (PAD)))
+#define T_ADVANCE 1.0f
+#define D_DFT 300.0f
+#define TARGET_FPS 60
+#define BG_COLOR RAYWHITE
+#define TEXT_COLOR LIGHTGRAY
+#define FONT_SIZE 20
+#define D_STEP 20.0f
+#define D_STEP_FINE 2.0f
+#define D_MIN 1.0f
+#define D_MAX 10000.0f
+
+// Application control keys
+#define KEY_NEXT_EASE_X KEY_RIGHT
+#define KEY_PREV_EASE_X KEY_LEFT
+#define KEY_NEXT_EASE_Y KEY_DOWN
+#define KEY_PREV_EASE_Y KEY_UP
+#define KEY_INCR_D_STEP KEY_W
+#define KEY_DECR_D_STEP KEY_Q
+#define KEY_INCR_D_FINE KEY_S
+#define KEY_DECR_D_FINE KEY_A
+#define KEY_PLAY_PAUSE KEY_ENTER
+#define KEY_RESTART KEY_SPACE
+#define KEY_TOGGLE_UNBOUNDED_T KEY_T
+
+
+// Easing types
+enum EasingTypes {
+    EASE_LINEAR_NONE,
+    EASE_LINEAR_IN,
+    EASE_LINEAR_OUT,
+    EASE_LINEAR_IN_OUT,
+    EASE_SINE_IN,
+    EASE_SINE_OUT,
+    EASE_SINE_IN_OUT,
+    EASE_CIRC_IN,
+    EASE_CIRC_OUT,
+    EASE_CIRC_IN_OUT,
+    EASE_CUBIC_IN,
+    EASE_CUBIC_OUT,
+    EASE_CUBIC_IN_OUT,
+    EASE_QUAD_IN,
+    EASE_QUAD_OUT,
+    EASE_QUAD_IN_OUT,
+    EASE_EXPO_IN,
+    EASE_EXPO_OUT,
+    EASE_EXPO_IN_OUT,
+    EASE_BACK_IN,
+    EASE_BACK_OUT,
+    EASE_BACK_IN_OUT,
+    EASE_BOUNCE_OUT,
+    EASE_BOUNCE_IN,
+    EASE_BOUNCE_IN_OUT,
+    EASE_ELASTIC_IN,
+    EASE_ELASTIC_OUT,
+    EASE_ELASTIC_IN_OUT,
+    NUM_EASING_TYPES,
+    EASING_NONE = NUM_EASING_TYPES
+};
+
+
+static float NoEase(float t, float b, float c, float d);  // NoEase function declaration, function used when "no easing" is selected for any axis
+
+
+// Easing functions reference data
+static const struct {
+    const char *name;
+    float (*func)(float, float, float, float);
+} Easings[] = {
+    [EASE_LINEAR_NONE] = {
+        .name = "EaseLinearNone",
+        .func = EaseLinearNone,
+    },
+    [EASE_LINEAR_IN] = {
+        .name = "EaseLinearIn",
+        .func = EaseLinearIn,
+    },
+    [EASE_LINEAR_OUT] = {
+        .name = "EaseLinearOut",
+        .func = EaseLinearOut,
+    },
+    [EASE_LINEAR_IN_OUT] = {
+        .name = "EaseLinearInOut",
+        .func = EaseLinearInOut,
+    },
+    [EASE_SINE_IN] = {
+        .name = "EaseSineIn",
+        .func = EaseSineIn,
+    },
+    [EASE_SINE_OUT] = {
+        .name = "EaseSineOut",
+        .func = EaseSineOut,
+    },
+    [EASE_SINE_IN_OUT] = {
+        .name = "EaseSineInOut",
+        .func = EaseSineInOut,
+    },
+    [EASE_CIRC_IN] = {
+        .name = "EaseCircIn",
+        .func = EaseCircIn,
+    },
+    [EASE_CIRC_OUT] = {
+        .name = "EaseCircOut",
+        .func = EaseCircOut,
+    },
+    [EASE_CIRC_IN_OUT] = {
+        .name = "EaseCircInOut",
+        .func = EaseCircInOut,
+    },
+    [EASE_CUBIC_IN] = {
+        .name = "EaseCubicIn",
+        .func = EaseCubicIn,
+    },
+    [EASE_CUBIC_OUT] = {
+        .name = "EaseCubicOut",
+        .func = EaseCubicOut,
+    },
+    [EASE_CUBIC_IN_OUT] = {
+        .name = "EaseCubicInOut",
+        .func = EaseCubicInOut,
+    },
+    [EASE_QUAD_IN] = {
+        .name = "EaseQuadIn",
+        .func = EaseQuadIn,
+    },
+    [EASE_QUAD_OUT] = {
+        .name = "EaseQuadOut",
+        .func = EaseQuadOut,
+    },
+    [EASE_QUAD_IN_OUT] = {
+        .name = "EaseQuadInOut",
+        .func = EaseQuadInOut,
+    },
+    [EASE_EXPO_IN] = {
+        .name = "EaseExpoIn",
+        .func = EaseExpoIn,
+    },
+    [EASE_EXPO_OUT] = {
+        .name = "EaseExpoOut",
+        .func = EaseExpoOut,
+    },
+    [EASE_EXPO_IN_OUT] = {
+        .name = "EaseExpoInOut",
+        .func = EaseExpoInOut,
+    },
+    [EASE_BACK_IN] = {
+        .name = "EaseBackIn",
+        .func = EaseBackIn,
+    },
+    [EASE_BACK_OUT] = {
+        .name = "EaseBackOut",
+        .func = EaseBackOut,
+    },
+    [EASE_BACK_IN_OUT] = {
+        .name = "EaseBackInOut",
+        .func = EaseBackInOut,
+    },
+    [EASE_BOUNCE_OUT] = {
+        .name = "EaseBounceOut",
+        .func = EaseBounceOut,
+    },
+    [EASE_BOUNCE_IN] = {
+        .name = "EaseBounceIn",
+        .func = EaseBounceIn,
+    },
+    [EASE_BOUNCE_IN_OUT] = {
+        .name = "EaseBounceInOut",
+        .func = EaseBounceInOut,
+    },
+    [EASE_ELASTIC_IN] = {
+        .name = "EaseElasticIn",
+        .func = EaseElasticIn,
+    },
+    [EASE_ELASTIC_OUT] = {
+        .name = "EaseElasticOut",
+        .func = EaseElasticOut,
+    },
+    [EASE_ELASTIC_IN_OUT] = {
+        .name = "EaseElasticInOut",
+        .func = EaseElasticInOut,
+    },
+    [EASING_NONE] = {
+        .name = "None",
+        .func = NoEase,
+    },
+};
+
+
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    Vector2 ballPos = { .x = START_X, .y = START_Y };
+    float t = 0.0f;        // Current time (in any unit measure, but same unit as duration)
+    float d = D_DFT;       // Total time it should take to complete (duration)
+    bool paused = true;
+    bool boundedT = true;  // If true, t will stop when d >= td, otherwise t will keep adding td to its value every loop
+
+    enum EasingTypes easingX = EASING_NONE;  // Easing selected for x axis
+    enum EasingTypes easingY = EASING_NONE;  // Easing selected for y axis
+
+    InitWindow(SCR_WIDTH, SCR_HEIGHT, "raylib [easings] example");
+    SetTargetFPS(TARGET_FPS);
+    //--------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        if (IsKeyPressed(KEY_TOGGLE_UNBOUNDED_T))
+            boundedT = 1 - boundedT;
+
+        // Choose easing for the X axis
+        if (IsKeyPressed(KEY_NEXT_EASE_X))
+        {
+            ++easingX;
+
+            if (easingX > EASING_NONE)
+                easingX = 0;
+        }
+        else if (IsKeyPressed(KEY_PREV_EASE_X))
+        {
+            if (easingX == 0)
+                easingX = EASING_NONE;
+            else
+                --easingX;
+        }
+
+        // Choose easing for the Y axis
+        if (IsKeyPressed(KEY_NEXT_EASE_Y))
+        {
+            ++easingY;
+
+            if (easingY > EASING_NONE)
+                easingY = 0;
+        }
+        else if (IsKeyPressed(KEY_PREV_EASE_Y))
+        {
+            if (easingY == 0)
+                easingY = EASING_NONE;
+            else
+                --easingY;
+        }
+
+        // Change d (duration) value
+        if (IsKeyPressed(KEY_INCR_D_STEP) && d < D_MAX - D_STEP)
+            d += D_STEP;
+        else if (IsKeyPressed(KEY_DECR_D_STEP) && d > D_MIN + D_STEP)
+            d -= D_STEP;
+
+        if (IsKeyDown(KEY_INCR_D_FINE) && d < D_MAX - D_STEP_FINE)
+            d += D_STEP_FINE;
+        else if (IsKeyDown(KEY_DECR_D_FINE) && d > D_MIN + D_STEP_FINE)
+            d -= D_STEP_FINE;
+
+        // Play, pause and restart controls
+        if (IsKeyPressed(KEY_RESTART) ||
+            IsKeyPressed(KEY_NEXT_EASE_X) || IsKeyPressed(KEY_PREV_EASE_X) ||
+            IsKeyPressed(KEY_NEXT_EASE_Y) || IsKeyPressed(KEY_PREV_EASE_Y) ||
+            IsKeyPressed(KEY_INCR_D_STEP) || IsKeyPressed(KEY_DECR_D_STEP) ||
+            IsKeyPressed(KEY_TOGGLE_UNBOUNDED_T) ||
+            IsKeyDown(KEY_INCR_D_FINE)  || IsKeyDown(KEY_DECR_D_FINE) ||
+            (IsKeyPressed(KEY_PLAY_PAUSE) && boundedT == true && t >= d))
+        {
+            t = 0.0f;
+            ballPos.x = START_X;
+            ballPos.y = START_Y;
+            paused = true;
+        }
+
+        if (IsKeyPressed(KEY_PLAY_PAUSE))
+            paused = 1 - paused;
+
+        // Movement computation
+        if ((paused == false) &&
+            ((boundedT == true && t < d) || boundedT == false))
+        {
+            ballPos.x = Easings[easingX].func(t, START_X, END_X - START_X, d);
+            ballPos.y = Easings[easingY].func(t, START_Y, END_Y - START_Y, d);
+            t += T_ADVANCE;
+        }
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+            ClearBackground(BG_COLOR);
+
+            // Draw information text
+            int line = 0;
+
+            DrawText(TextFormat("Easing x: %s", Easings[easingX].name), 0, FONT_SIZE * (line++), FONT_SIZE, TEXT_COLOR);
+            DrawText(TextFormat("Easing y: %s", Easings[easingY].name), 0, FONT_SIZE * (line++), FONT_SIZE, TEXT_COLOR);
+            DrawText(TextFormat("t (%c) = %.2f d = %.2f", (boundedT == true)? 'b' : 'u', t, d),
+                     0, FONT_SIZE * (line++), FONT_SIZE, TEXT_COLOR);
+
+            // Draw instructions text
+            line = 1;
+            DrawText("Use ENTER to play or pause movement, use SPACE to restart", 0, SCR_HEIGHT - FONT_SIZE * (line++), FONT_SIZE, TEXT_COLOR);
+            DrawText("Use D and W or A and S keys to change duration", 0, SCR_HEIGHT - FONT_SIZE * (line++), FONT_SIZE, TEXT_COLOR);
+            DrawText("Use LEFT or RIGHT keys to choose easing for the x axis", 0, SCR_HEIGHT - FONT_SIZE * (line++), FONT_SIZE, TEXT_COLOR);
+            DrawText("Use UP or DOWN keys to choose easing for the y axis", 0, SCR_HEIGHT - FONT_SIZE * (line++), FONT_SIZE, TEXT_COLOR);
+
+            // Draw ball
+            DrawCircleV(ballPos, BALL_RADIUS, BALL_COLOR);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+    CloseWindow();
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}
+
+
+// NoEase function, used when "no easing" is selected for any axis. It just ignores all parameters besides b.
+static float NoEase(float t, float b, float c, float d)
+{
+    float burn = t + b + c + d;  // Hack to avoid compiler warning (about unused variables)
+    d += burn;
+
+    return b;
+}