added animation and keyboard controls to rlgl mesh Instancing example (#1678)

examples/shaders/shaders_rlgl_mesh_instanced.c

@@ -25,6 +25,10 @@
 
 #define GLSL_VERSION 330
 
+float maxf(float a, float b){
+    return (a > b ? a : b);
+}
+
 //------------------------------------------------------------------------------------
 // Program main entry point
 //------------------------------------------------------------------------------------
@@ -34,13 +38,20 @@ int main(void)
     //--------------------------------------------------------------------------------------
     const int screenWidth = 800;
     const int screenHeight = 450;
+    int speed = 30;                 // speed of jump animation
+    int groups = 2;                 // count of separate groups jumping around
+    float amp = 10;                 // maximum amplitude of jump
+    float variance = 0.8;           // global variance in jump height
+    float loop=0;                   // individual cube's computed loop timer .
+    float x=0,y=0,z=0;              // used for various 3D coordinate & vector ops.
+    const int fps = 60;
 
     SetConfigFlags(FLAG_MSAA_4X_HINT);  // Enable Multi Sampling Anti Aliasing 4x (if available)
     InitWindow(screenWidth, screenHeight, "raylib [shaders] example - rlgl mesh instanced");
 
     // Define the camera to look into our 3d world
     Camera camera = { 0 };
-    camera.position = (Vector3){ 125.0f, 125.0f, 125.0f };
+    camera.position = (Vector3){ -125.0f, 125.0f, -125.0f };
     camera.target = (Vector3){ 0.0f, 0.0f, 0.0f };
     camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };
     camera.fovy = 45.0f;
@@ -56,14 +67,14 @@ int main(void)
     // Scatter random cubes around
     for (int i = 0; i < count; i++)
     {
-        float x = (float)GetRandomValue(-50, 50);
-        float y = (float)GetRandomValue(-50, 50);
-        float z = (float)GetRandomValue(-50, 50);
+        x = GetRandomValue(-50, 50);
+        y = GetRandomValue(-50, 50);
+        z = GetRandomValue(-50, 50);
         translations[i] = MatrixTranslate(x, y, z); 
 
-        x = (float)GetRandomValue(0, 360);
-        y = (float)GetRandomValue(0, 360);
-        z = (float)GetRandomValue(0, 360);
+        x = GetRandomValue(0, 360);
+        y = GetRandomValue(0, 360);
+        z = GetRandomValue(0, 360);
         Vector3 axis = Vector3Normalize((Vector3){x, y, z});
         float angle = (float)GetRandomValue(0, 10) * DEG2RAD;
 
@@ -91,27 +102,64 @@ int main(void)
     material.shader = shader;
     material.maps[MATERIAL_MAP_DIFFUSE].color = RED;
     
-    SetCameraMode(camera, CAMERA_FREE); // Set a free camera mode
+    SetCameraMode(camera, CAMERA_ORBITAL); // Set a free camera mode
 
-    SetTargetFPS(60);                   // Set our game to run at 60 frames-per-second
+    SetTargetFPS(fps);                   // Set our game to run at 60 frames-per-second
     //--------------------------------------------------------------------------------------
 
     // Main game loop
+    int frame = 0;                      // simple frame counter to manage animation
     while (!WindowShouldClose())        // Detect window close button or ESC key
     {
+
         // Update
         //----------------------------------------------------------------------------------
         UpdateCamera(&camera);
+        frame ++;
+
+        //if (IsKeyDown(KEY_RIGHT)) ballPosition.x += 2.0f;
+        //if (IsKeyDown(KEY_LEFT)) ballPosition.x -= 2.0f;
+        if (IsKeyDown(KEY_UP)) amp += 0.5;
+        if (IsKeyDown(KEY_DOWN)) amp = amp <= 1 ? 1 : amp - 1.0;
+        if (IsKeyDown(KEY_LEFT))  variance = variance <=0 ? 0 : variance - 0.01;
+        if (IsKeyDown(KEY_RIGHT)) variance = variance >=1 ? 1 : variance + 0.01;
+        if (IsKeyDown(KEY_ONE)) groups = 1;
+        if (IsKeyDown(KEY_TWO)) groups = 2;
+        if (IsKeyDown(KEY_THREE)) groups = 3;
+        if (IsKeyDown(KEY_FOUR)) groups = 4;
+        if (IsKeyDown(KEY_FIVE)) groups = 5;
+        if (IsKeyDown(KEY_SIX)) groups = 6;
+        if (IsKeyDown(KEY_SEVEN)) groups = 7;
+        if (IsKeyDown(KEY_EIGHT)) groups = 8;
+        if (IsKeyDown(KEY_NINE)) groups = 9;
+        if (IsKeyDown(KEY_W)) {groups=7; amp = 25; speed=18; variance=0.70;}
+            
+        if (IsKeyDown(KEY_EQUAL)) speed = speed <= (fps *.25)  ? (fps *.25) : speed * 0.95;
+        if (IsKeyDown(KEY_KP_ADD)) speed = speed <= (fps *.25)  ? (fps *.25) : speed * 0.95;
+            
+        if (IsKeyDown(KEY_MINUS)) speed = maxf(speed * 1.02, speed + 1) ;
+        if (IsKeyDown(KEY_KP_SUBTRACT)) maxf(speed * 1.02, speed + 1) ;
+
 
         // Update the light shader with the camera view position
         float cameraPos[3] = { camera.position.x, camera.position.y, camera.position.z };
         SetShaderValue(shader, shader.locs[SHADER_LOC_VECTOR_VIEW], cameraPos, SHADER_UNIFORM_VEC3);
 
-        // Apply per-instance rotations
-        for (int i = 0; i < count; i++)
-        {
+        // Apply per-instance transformations
+        for (int i = 0; i < count; i++){
             rotations[i] = MatrixMultiply(rotations[i], rotationsInc[i]);
             transforms[i] = MatrixMultiply(rotations[i], translations[i]);
+            
+            // get the animation cycle's frame for this instance.
+            loop = (float)( (frame + (int)(((float)(i % groups)/groups) * speed)) % speed)  / speed;
+            
+            // calculate the y according to loop cycle
+            y =  ( sinf( loop * PI * 2 )  )  * (amp )* ((1 - variance) +  ((variance) * (float)(i % (groups * 10)) / (groups * 10)));
+            
+            // clamp to floor
+            y = (y<0 ? 0 : y);
+            
+            transforms[i] = MatrixMultiply(transforms[i], MatrixTranslate(0, y, 0));
         }
         //----------------------------------------------------------------------------------
 
@@ -124,8 +172,40 @@ int main(void)
             BeginMode3D(camera);
                 rlDrawMeshInstanced(cube, material, transforms, count);
             EndMode3D();
-
+            int u = 10;
+            int u2 = u + 40;
+            int u3 = u2 + 110;
+            int v = 300;
             DrawText("A CUBE OF DANCING CUBES!", 490, 10, 20, MAROON);
+            DrawText("PRESS KEYS:", u, v, 20, BLACK);
+            
+            DrawText("1 - 9", u, v+=25, 10, BLACK);  
+            DrawText(": Number of groups", u2, v , 10, BLACK);
+            DrawText(TextFormat(": %d", groups), u3, v , 10, BLACK);
+            
+            DrawText("UP", u, v+=15, 10, BLACK);  
+            DrawText(": increase amplitude", u2, v, 10, BLACK);
+            DrawText(TextFormat(": %.2f", amp), u3, v , 10, BLACK);
+            
+            DrawText("DOWN", u, v+=15, 10, BLACK);  
+            DrawText(": decrease amplitude", u2, v, 10, BLACK);
+            
+            DrawText("LEFT", u, v+=15, 10, BLACK);  
+            DrawText(": decrease variance", u2, v, 10, BLACK);
+            DrawText(TextFormat(": %.2f", variance), u3, v , 10, BLACK);
+            
+            DrawText("RIGHT", u, v+=15, 10, BLACK);  
+            DrawText(": increase variance", u2, v, 10, BLACK);
+            
+            DrawText("+/=", u, v+=15, 10, BLACK);  
+            DrawText(": increase speed", u2, v, 10, BLACK);
+            DrawText(TextFormat(": %d = %f loops/sec", speed, ((float)fps / speed)), u3, v , 10, BLACK);
+            
+            DrawText("-", u, v+=15, 10, BLACK);  
+            DrawText(": decrease speed", u2, v, 10, BLACK);
+            
+            DrawText("W", u, v+=15, 10, BLACK);  
+            DrawText(": Wild setup!", u2, v, 10, BLACK);
             
             DrawFPS(10, 10);