System - Polkm105/DesignPatternPractice GitHub Wiki

PARTIAL

This section contains all functions relating to CP_System

Table Of Contents

CP_System_SetWindowSize

This function modifies the size of the window. Typically, the window size is set in the init function.

Function

void CP_System_SetWindowSize(int new_width, int new_height);

Parameters

  • new_width - (int) the width to set the window to
  • new_height - (int) the height to set the window to

Return

This function does not return anything.

Example

void init() 
{
  // Set the window size to a small square
  CP_System_SetWindowSize(10, 10);

  // Set the background to white
  CP_Graphics_ClearBackground(CP_Color_Create(255, 255, 255, 255));
}

Related

CP_System_SetWindowPosition

CP_System_Fullscreen

This function sets the window to fullscreen. It will automatically sets the window's pixel width and height to the monitor's width and height. Use CP_System_FullscreenAdvanced to specify a pixel width and height for the fullscreen window.

Function

void CP_System_Fullscreen(void);

Parameters

This function has no parameters.

Return

This function does not return anything.

Example

void init() 
{
  // Set the window to fill the screen
  CP_System_Fullscreen();

  // Set the background to black
  CP_Graphics_ClearBackground(CP_Color_Create(0, 0, 0, 255));
}

Related

CP_System_FullscreenAdvanced

The function CP_System_FullscreenAdvanced() sets the window to fullscreen like CP_System_Fullscreen but lets you set the pixel aspect ratio of the screen as well. If you try to set the screen to an aspect ratio unsupported by the monitor, it will be set to the closest aspect ratio possible.

Function

void CP_System_FullscreenAdvanced(int targetWidth, int targetHeight);

Parameters

  • targetWidth - (int) The pixel width of the window.
  • targetHeight - (int) The pixel height of the window.

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));

  // Set the window to fullscreen 1280x720
  CP_System_FullscreenAdvanced(1280, 720);
}

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

  // Draw the square
  CP_Graphics_DrawRect(x_pos, 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);
  else if (CP_Input_KeyTriggered(KEY_Q))
    CP_Engine_Terminate();
}

Related

CP_System_GetWindowWidth

Gets the display width of the window excluding the window frame. This is the width of the canvas you are drawing to.

Function

int CP_System_GetWindowWidth(void);

Parameters

This function has no parameters.

Return

int

Example

void update() 
{
    // Clear the background to a blue color
    CP_Graphics_ClearBackground(CP_Color_Create(20, 200, 255, 255));

    // Draw a rectangle at the mouse position
    CP_Graphics_DrawRect(CP_System_GetWindowWidth() / 2.0f, CP_System_GetWindowHeight() / 2.0f, 25.0f, 25.0f);
}

Related

CP_System_GetWindowHeight

Gets the display height of the window excluding the window frame. This is the height of the canvas you are drawing to.

Function

int CP_System_GetWindowHeight(void);

Parameters

This function has no parameters.

Return

int

Example

void update() 
{
    // Clear the background to a blue color
    CP_Graphics_ClearBackground(CP_Color_Create(20, 200, 255, 255));

    // Draw a rectangle at the mouse position
    CP_Graphics_DrawRect(CP_System_GetWindowWidth() / 2.0f, CP_System_GetWindowHeight() / 2.0f, 25.0f, 25.0f);
}

Related

CP_System_GetDisplayWidth

CP_System_GetDisplayHeight

CP_System_GetWindowHandle

Returns the window handle (HWND) of the program running. See https://docs.microsoft.com/en-us/windows/win32/apiindex/windows-api-list for windows.h documentation and examples.

Function

HWND CP_System_GetWindowHandle(void);

Parameters

This function has no parameters.

Return

HWND - Windows type that represents the handle to the window.

CP_System_SetWindowTitle

Sets the title of the running program.

Function

void CP_System_SetWindowTitle(const char* title);

Parameters

  • title - (const char*) The string containing the title to change the title bar to.

Return

This function does not return anything.

Example

void update()
{
  // Set the window title to the number of frames that have passed.
  char buffer[256] = { 0 };
  sprintf_s(buffer, 256, "%d frames have passed", frameCount);
  CP_System_SetWindowTitle(buffer);
}

CP_System_ShowCursor

This function sets whether the cursor is visible or not. Typically, it is used in the init function.

Function

void CP_System_ShowCursor(CP_BOOL show);

Parameters

  • show - (CP_BOOL) True/False for whether the cursor is visible.

Return

This function does not return anything.

Example

CP_BOOL cursor = TRUE;

void init()
{
  // Set the window to fullscreen
  CP_System_Fullscreen();

  // Show the cursor
  CP_System_ShowCursor(cursor);
}

void update()
{
  // Check if the spacebar is triggered
  if (CP_Input_KeyTriggered(KEY_SPACE))
  {
    // Swap whether the cursor is shown
    cursor = !cursor;
    CP_System_ShowCursor(cursor);
  }
}

Related

CP_System_GetFrameCount

Returns the current frame count. The frame count starts at 0 when the program launches and increments every frame until the program ends.

Note: the frame count can't be set by the user and isn't reset when changing game states

Function

int CP_System_GetFrameCount();

Parameters

This function has no parameters.

Return

int

Example

void update(void) 
{
    // print the current frame count to the center of the window
    CP_Settings_TextSize(200);
    CP_Settings_TextAlignment(CP_TEXT_ALIGN_H_CENTER, CP_TEXT_ALIGN_V_MIDDLE);
    CP_Graphics_ClearBackground(CP_Color_Create(200, 200, 200, 255));
    CP_Settings_Fill(CP_Color_Create(100, 20, 100, 255));
    
    int currentFrameCount = CP_System_GetFrameCount();
    
    char buffer[16] = { 0 };
    sprintf_s(buffer, _countof(buffer), "%i", currentFrameCount);
    CP_Font_DrawText(buffer, 200, 200);
}

Related

CP_System_GetFrameRate

Returns the current frames per second.

Function

float CP_System_GetFrameRate(void);

Parameters

This function has no parameters.

Return

float

Example

void update(void) 
{
    // print the current frame rate to the center of the window
    CP_Settings_TextSize(200);
    CP_Settings_TextAlignment(CP_TEXT_ALIGN_H_CENTER, CP_TEXT_ALIGN_V_MIDDLE);
    CP_Graphics_ClearBackground(CP_Color_Create(200, 200, 200, 255));
    CP_Settings_Fill(CP_Color_Create(100, 20, 100, 255));
    
    float currentFrameRate = CP_System_GetFrameRate();
    
    char buffer[16] = { 0 };
    sprintf_s(buffer, _countof(buffer), "%.1f", currentFrameRate );
    CP_Font_DrawText(buffer, 200, 200);
}

Related

CP_System_SetFrameRate

Sets the target frame rate (fps) for the application.

The internal frame rate controller manages when each update call happens. If the processing required to complete one update finishes quickly then the frame rate controller will idle the CPU. Once the total desired frame time has passed it will then start the next frame. If the processing required to complete one update takes longer than one frame's worth of time then the next frame will start immediately.

Function

void CP_System_SetFrameRate(float fps)

Parameters

  • fps - the target application update speed in frames per second.

Return

This function does not return anything.

Example

void init(void)
{
    // set framerate to 2 fps (slow)
    CP_System_SetFrameRate(2.0f);

    // initialize settings
    CP_Settings_TextSize(200);
    CP_Settings_TextAlignment(CP_TEXT_ALIGN_H_CENTER, CP_TEXT_ALIGN_V_MIDDLE);
    CP_Settings_Fill(CP_Color_Create(100, 20, 100, 255));
}

void update(void) 
{
    // clear the screen
    CP_Graphics_ClearBackground(CP_Color_Create(200, 200, 200, 255));

    // print the current frame count to the center of the window
    int currentFrameCount = CP_System_GetFrameCount();
    
    char buffer[16] = { 0 };
    sprintf_s(buffer, _countof(buffer), "%i", currentFrameCount);
    CP_Font_DrawText(buffer, 200, 200);
}

Related

CP_System_GetDt

Returns the elapsed time from the last frame. This is very important when making frame independent calculations such as movement or physics.

Function

float CP_System_GetDt(void);

Parameters

This function has no parameters.

Return

float

Example

void init(void)
{
    // initialize settings
    CP_Settings_TextSize(150);
    CP_Settings_TextAlignment(CP_TEXT_ALIGN_H_CENTER, CP_TEXT_ALIGN_V_MIDDLE);
    CP_Settings_Fill(CP_Color_Create(100, 20, 100, 255));
}

void update(void)
{
    // clear the background
    CP_Graphics_ClearBackground(CP_Color_Create(200, 200, 200, 255));

    // get dt and then print total elapsed time
    float currentElapsedTime = CP_System_GetDt();
    static float totalElapsedTime = 0;
    totalElapsedTime += currentElapsedTime;

    char buffer[16] = { 0 };
    sprintf_s(buffer, _countof(buffer), "%.2f", totalElapsedTime);
    CP_Font_DrawText(buffer, 200, 200);
}

Related

CP_System_GetMillis

Returns the total milliseconds from the start of the program.

NOTE: This number is always increasing and cannot be changed or reset by the user.

Function

float CP_System_GetMillis(void);

Parameters

This function has no parameters.

Return

float

Example

void init(void)
{
    // initialize settings
    CP_Settings_TextSize(150);
    CP_Settings_TextAlignment(CP_TEXT_ALIGN_H_CENTER, CP_TEXT_ALIGN_V_MIDDLE);
    CP_Settings_Fill(CP_Color_Create(100, 20, 100, 255));
}

void update(void) 
{
    // clear the background
    CP_Graphics_ClearBackground(CP_Color_Create(200, 200, 200, 255));

    // print milliseconds since program start
    float totalMillis = CP_System_GetMillis();

    char buffer[16] = { 0 };
    sprintf_s(buffer, _countof(buffer), "%.1f", totalMillis);
    CP_Font_DrawText(buffer, 200, 200);
}

Related

CP_System_GetSeconds

Returns the total number of seconds from the start of the program.

NOTE: This number is always increasing and cannot be changed or reset by the user.

Function

float CP_System_GetSeconds(void);

Parameters

This function has no parameters.

Return

float

Example

void init(void)
{
    // initialize settings
    CP_Settings_TextSize(150);
    CP_Settings_TextAlignment(CP_TEXT_ALIGN_H_CENTER, CP_TEXT_ALIGN_V_MIDDLE);
    CP_Settings_Fill(CP_Color_Create(100, 20, 100, 255));
}

void update(void) 
{
    // clear the background
    CP_Graphics_ClearBackground(CP_Color_Create(200, 200, 200, 255));

    // print seconds since program start
    float totalSeconds = CP_System_GetSeconds();

    char buffer[16] = { 0 };
    sprintf_s(buffer, _countof(buffer), "%.2f", totalSeconds);
    CP_Font_DrawText(buffer, 200, 200);
}

Related