Engine

This section contains all of the Engine functions.

Table of Contents

• CP_Engine_Run
• CP_Engine_Terminate
• CP_Engine_SetNextGameState
• CP_Engine_SetNextGameStateForced
• CP_Engine_SetPreUpdateFunction NEW
• CP_Engine_SetPostUpdateFunction NEW

CP_Engine_Run()

This function is what starts the CProcessing engine. Before calling CP_Engine_Run(), CP_Engine_SetNextGameState or CP_Engine_SetNextGameStateForced must be called to set the initial state of the program. Failing to do so will cause the program to end immediately.

Function

void CP_Engine_Run();

Parameters

This function has no parameters.

Return

This function does not return anything.

Example

void init()
{
    /* Set the size of the window */
    CP_System_Size(500, 500);
}

void update()
{
    /* Set the background color to black every frame */
    CP_Graphics_ClearBackground(CP_Color_Create(0, 0, 0, 255));

    /* Draw a rectangle at the mouse position */
    CP_Graphics_DrawRect(CP_Input_GetMouseX(), CP_Input_GetMouseY(), 50, 50);
}

int main()
{
    // Set the initial game state
    CP_Engine_SetNextGameState(init, update, NULL);

    // Run the program
    CP_Engine_Run();
}

Related

• CP_System_Size
• CP_Graphics_ClearBackground
• CP_Color_Create
• CP_Graphics_DrawRect
• CP_Input_GetMouseX
• CP_Input_GetMouseY

CP_Engine_Terminate()

This will end the program after completing the current frame.

Function

void CP_Engine_Terminate();

Parameters

This function has no parameters.

Return

This function does not return anything.

Example

// Horizontal position of the square
float x_pos;
void init()
{
    // Start the square at the left of the screen
    x_pos = 0;

    // Set the square to draw yellow
    CP_Settings_Fill(CP_Color_Create(255, 255, 0, 255));
}

void update()
{
    // Set background to black
    CP_Graphics_ClearBackground(CP_Color_Create(0, 0, 0, 255));

    // Draw the square
    CP_Graphics_DrawRect(x_pos, (float)CP_System_GetWindowHeight()/ 2.0f, 100, 100);
    x_pos += 2;

    // If space pressed, reset the state
    if (CP_Input_KeyTriggered(KEY_SPACE))
    {
        CP_Engine_SetNextGameStateForced(init, update, NULL);
    }

    // If escape is pressed, end the program
    if (CP_Input_KeyTriggered(KEY_ESCAPE))
    {
        CP_Engine_Terminate();
    }
}

int main(void)
{
    // Set the initial game state
    CP_Engine_SetNextGameState(init, update, NULL);

    // Run the program
    CP_Engine_Run();
}

Related

• CP_Color_Create
• CP_Graphics_ClearBackground
• CP_Graphics_DrawRect
• CP_Input_KeyTriggered
• CP_Settings_Fill
• CP_System_GetWindowHeight

CP_Engine_SetNextGameState()

This sets the next state for the program to enter. This will call the shutdown function of the current state if own exists. Calling CP_Engine_SetNextGameState() on the same state you are currently in will have no effect, but calling CP_Engine_SetNextGameStateForced will restart the current state.

Function

void CP_Engine_SetNextGameState(FunctionPtr init, FunctionPtr update, FunctionPtr shutdown);

Parameters

• init (FunctionPtr) - The name of the function called once when the state first begins. This can be NULL if no initialization is needed for your state.
• update (FunctionPtr) - The name of the function called every frame to update the state.
• shutdown (FunctionPtr) - The name of the function called when you leave a state. This occurs when you call CP_Engine_SetNextGameState or CP_Engine_SetNextGameStateForced to change states. This can be NULL if no cleanup is needed for your state.

Return

This function does not return anything.

Example

void init()
{
    /* Set the size of the window */
    CP_System_Size(500, 500);
}

void update()
{
    /* Set the background color to black every frame */
    CP_Graphics_ClearBackground(CP_Color_Create(0, 0, 0, 255));

    /* Draw a rectangle at the mouse position */
    CP_Graphics_DrawRect(CP_Input_GetMouseX(), CP_Input_GetMouseY(), 50, 50);
}

int main()
{
    // Set the initial game state
    CP_Engine_SetNextGameState(init, update, NULL);

    // Run the program
    CP_Engine_Run();
}

Related

• CP_Color_Create
• CP_Graphics_ClearBackground
• CP_Graphics_DrawRect
• CP_Input_GetMouseX
• CP_System_Size

CP_Engine_SetNextGameStateForced()

This sets the next state for the program to enter. This will call the shutdown function of the current state if it exists. Calling CP_Engine_SetNextGameStateForced() allows you to reset your current game state, while CP_Engine_SetNextGameState with the current game state will not.

Function

void CP_Engine_SetNextGameStateForced(FunctionPtr init, FunctionPtr update, FunctionPtr shutdown);

Parameters

• init (FunctionPtr) - The name of the function called once when the state first begins. This can be NULL if no initialization is needed for your state.
• update (FunctionPtr) - The name of the function called every frame to update the state.
• shutdown (FunctionPtr) - The name of the function called when you leave a state. This occurs when you call CP_Engine_SetNextGameState or CP_Engine_SetNextGameStateForced() to change states. This can be NULL if no cleanup is needed for your state.

Return

This function does not return anything.

Example

// Horizontal position of the square
float x_pos;
void init()
{
    // Start the square at the left of the screen
    x_pos = 0;

    // Set the square to draw yellow
    CP_Settings_Fill(CP_Color_Create(255, 255, 0, 255));
}

void update()
{
    // Set background to black
    CP_Graphics_ClearBackground(CP_Color_Create(0, 0, 0, 255));

    // Draw the square
    CP_Graphics_DrawRect(x_pos, (float)CP_System_GetCanvasHeight() / 2.0f, 100, 100);
    x_pos += 2;

    // If space pressed, reset the state
    if (CP_Input_KeyTriggered(KEY_SPACE))
        CP_Engine_SetNextGameStateForced(init, update, NULL);
}

int main(void)
{
    // Set the initial game state
    CP_Engine_SetNextGameState(init, update, NULL);

    // Run the program
    CP_Engine_Run();
}

Related

• CP_Color_Create
• CP_Graphics_ClearBackground
• CP_Graphics_DrawRect
• CP_Input_KeyTriggered
• CP_Settings_Fill
• CP_System_GetCanvasHeight

CP_Engine_SetPreUpdateFunction()

This sets a function which will be called immediately before the current state's update function. This function is independent of the game state: it will continue to be called even if the game state is changed.

Function

void CP_Engine_SetPreUpdateFunction(FunctionPtr function);

Parameters

• function (FunctionPtr) - The name of the function to be called before the update.

Return

This function does not return anything.

Example

void preUpdate()
{
    // Change the fill color
    CP_Settings_Fill(CP_Color_Create(187, 24, 211, 255));
}

void init()
{
    CP_Engine_SetPreUpdateFunction(preUpdate);
}

Related

• CP_Settings_Fill

CP_Engine_SetPostUpdateFunction()

This sets a function which will be called immediately after the current state's update function. This function is independent of the game state: it will continue to be called even if the game state is changed.

Function

void CP_Engine_SetPostUpdateFunction(FunctionPtr function);

Parameters

• function (FunctionPtr) - The name of the function to be called after the update.

Return

This function does not return anything.

Example

void postUpdate()
{
    // Change the fill color
    CP_Settings_Fill(CP_Color_Create(187, 24, 211, 255));
}

void init()
{
    CP_Engine_SetPostUpdateFunction(postUpdate);
}

Related

• CP_Settings_Fill