raylib/src/core.c
2013-11-23 13:30:54 +01:00

582 lines
21 KiB
C

/*********************************************************************************************
*
* raylib.core
*
* Basic functions to manage Windows, OpenGL context and Input
*
* Uses external lib:
* GLFW3 - Window, context and Input management (static lib version)
*
* Copyright (c) 2013 Ramon Santamaria (Ray San - raysan@raysanweb.com)
*
* This software is provided "as-is", without any express or implied warranty. In no event
* will the authors be held liable for any damages arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose, including commercial
* applications, and to alter it and redistribute it freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not claim that you
* wrote the original software. If you use this software in a product, an acknowledgment
* in the product documentation would be appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not be misrepresented
* as being the original software.
*
* 3. This notice may not be removed or altered from any source distribution.
*
**********************************************************************************************/
#include "raylib.h"
#include <GLFW/glfw3.h> // GLFW3 lib: Windows, OpenGL context and Input management
//#include <GL/gl.h> // OpenGL functions (GLFW3 already includes gl.h)
#include <stdio.h> // Standard input / output lib
#include <stdlib.h> // Declares malloc() and free() for memory management
#include <math.h> // Math related functions, tan() on SetPerspective
#include "vector3.h" // Basic Vector3 functions
//#define GLFW_DLL // Using GLFW DLL on Windows -> No, we use static version!
//----------------------------------------------------------------------------------
// Defines and Macros
//----------------------------------------------------------------------------------
// Nop...
//----------------------------------------------------------------------------------
// Types and Structures Definition
//----------------------------------------------------------------------------------
typedef Color pixel;
//----------------------------------------------------------------------------------
// Global Variables Definition
//----------------------------------------------------------------------------------
static GLFWwindow* window; // Main window
static bool fullscreen; // Fullscreen mode track
static double currentTime, previousTime; // Used to track timmings
static double updateTime, drawTime; // Time measures for update and draw
static double frameTime; // Time measure for one frame
static double targetTime = 0; // Desired time for one frame, if 0 not applied
static int windowWidth, windowHeight; // Required to switch between windowed/fullscren mode (F11)
static char *windowTitle; // Required to switch between windowed/fullscren mode (F11)
//----------------------------------------------------------------------------------
// Other Modules Functions Declaration (required by core)
//----------------------------------------------------------------------------------
extern void LoadDefaultFont(); // [Module: text] Loads default font on InitWindow()
extern void UnloadDefaultFont(); // [Module: text] Unloads default font from GPU memory
extern void WriteBitmap(const char *fileName, const pixel *imgDataPixel, int width, int height); // [Module: textures] Writes a bitmap (BMP) file
//----------------------------------------------------------------------------------
// Module specific Functions Declaration
//----------------------------------------------------------------------------------
static void InitGraphicsDevice(); // Initialize Graphics Device (OpenGL stuff)
static void ErrorCallback(int error, const char *description); // GLFW3 Error Callback, runs on GLFW3 error
static void KeyCallback(GLFWwindow* window, int key, int scancode, int action, int mods); // GLFW3 Keyboard Callback, runs on key pressed
static void WindowSizeCallback(GLFWwindow* window, int width, int height); // GLFW3 WindowSize Callback, runs when window is resized
static void CameraLookAt(Vector3 position, Vector3 target, Vector3 up); // Setup camera view (updates MODELVIEW matrix)
static void SetPerspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar); // Setup view projection (updates PROJECTION matrix)
static void TakeScreenshot(); // Takes a bitmap (BMP) screenshot and saves it in the same folder as executable
//----------------------------------------------------------------------------------
// Module Functions Definition - Window and OpenGL Context Functions
//----------------------------------------------------------------------------------
// Initialize Window and Graphics Context (OpenGL)
void InitWindow(int width, int height, char* title)
{
glfwSetErrorCallback(ErrorCallback);
if (!glfwInit()) exit(1);
//glfwWindowHint(GLFW_SAMPLES, 4); // If called before windows creation, enables multisampling x4 (MSAA), default is 0
window = glfwCreateWindow(width, height, title, NULL, NULL);
windowWidth = width;
windowHeight = height;
windowTitle = title;
if (!window)
{
glfwTerminate();
exit(1);
}
glfwSetWindowSizeCallback(window, WindowSizeCallback);
glfwMakeContextCurrent(window);
glfwSetKeyCallback(window, KeyCallback);
glfwSwapInterval(0); // Disables GPU v-sync (if set), so frames are not limited to screen refresh rate (60Hz -> 60 FPS)
// If not set, swap interval uses GPU v-sync configuration
// Framerate can be setup using SetTargetFPS()
InitGraphicsDevice();
previousTime = glfwGetTime();
LoadDefaultFont();
}
// Close Window and Terminate Context
void CloseWindow()
{
UnloadDefaultFont();
glfwDestroyWindow(window);
glfwTerminate();
}
// Detect if KEY_ESCAPE pressed or Close icon pressed
bool WindowShouldClose()
{
return (glfwWindowShouldClose(window));
}
// Fullscreen toggle (by default F11)
void ToggleFullscreen()
{
if (glfwGetKey(window, GLFW_KEY_F11))
{
fullscreen = !fullscreen; // Toggle fullscreen flag
glfwDestroyWindow(window); // Destroy the current window (we will recreate it!)
// NOTE: Window aspect ratio is always windowWidth / windowHeight
if (fullscreen) window = glfwCreateWindow(windowWidth, windowHeight, windowTitle, glfwGetPrimaryMonitor(), NULL); // Fullscreen mode
else window = glfwCreateWindow(windowWidth, windowHeight, windowTitle, NULL, NULL);
if (!window)
{
glfwTerminate();
exit(1);
}
glfwMakeContextCurrent(window);
glfwSetKeyCallback(window, KeyCallback);
InitGraphicsDevice();
}
}
// Sets Background Color
void ClearBackground(Color color)
{
// Color values clamp to 0.0f(0) and 1.0f(255)
float r = (float)color.r / 255;
float g = (float)color.g / 255;
float b = (float)color.b / 255;
float a = (float)color.a / 255;
glClearColor(r, g, b, a);
}
// Setup drawing canvas to start drawing
void BeginDrawing()
{
currentTime = glfwGetTime(); // glfwGetTime() returns a 'double' containing the number of elapsed seconds since glfwInit() was called
updateTime = currentTime - previousTime;
previousTime = currentTime;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear used buffers, Depth Buffer is used for 3D
glLoadIdentity(); // Reset current matrix (MODELVIEW)
glTranslatef(0.375, 0.375, 0); // HACK to have 2D pixel-perfect drawing on OpenGL
}
// End canvas drawing and Swap Buffers (Double Buffering)
void EndDrawing()
{
glfwSwapBuffers(window); // Swap back and front buffers
glfwPollEvents(); // Register keyboard/mouse events
currentTime = glfwGetTime();
drawTime = currentTime - previousTime;
previousTime = currentTime;
frameTime = updateTime + drawTime;
double extraTime = 0;
while (frameTime < targetTime)
{
// Implement a delay
currentTime = glfwGetTime();
extraTime = currentTime - previousTime;
previousTime = currentTime;
frameTime += extraTime;
}
}
// Initializes 3D mode for drawing (Camera setup)
void Begin3dMode(Camera camera)
{
//glEnable(GL_LIGHTING); // TODO: Setup proper lighting system (raylib 1.x)
glMatrixMode(GL_PROJECTION); // Switch to projection matrix
glPushMatrix(); // Save previous matrix, which contains the settings for the 2d ortho projection
glLoadIdentity(); // Reset current matrix (PROJECTION)
SetPerspective(45.0f, (GLfloat)windowWidth/(GLfloat)windowHeight, 0.1f, 100.0f); // Setup perspective projection
glMatrixMode(GL_MODELVIEW); // Switch back to modelview matrix
glLoadIdentity(); // Reset current matrix (MODELVIEW)
CameraLookAt(camera.position, camera.target, camera.up); // Setup Camera view
}
// Ends 3D mode and returns to default 2D orthographic mode
void End3dMode()
{
glMatrixMode(GL_PROJECTION); // Switch to projection matrix
glPopMatrix(); // Restore previous matrix (PROJECTION) from matrix stack
glMatrixMode(GL_MODELVIEW); // Get back to modelview matrix
glLoadIdentity(); // Reset current matrix (MODELVIEW)
glTranslatef(0.375, 0.375, 0); // HACK to ensure pixel-perfect drawing on OpenGL (after exiting 3D mode)
//glDisable(GL_LIGHTING); // TODO: Setup proper lighting system (raylib 1.x)
}
// Set target FPS for the game
void SetTargetFPS(int fps)
{
targetTime = 1 / (float)fps;
printf("TargetTime per Frame: %f seconds\n", (float)targetTime);
}
// Returns current FPS
float GetFPS()
{
return (1/(float)frameTime);
}
// Returns time in seconds for one frame
float GetFrameTime()
{
// As we are operating quite a lot with frameTime, it could be no stable
// so we round it before before passing around to be used
// NOTE: There are still problems with high framerates (>500fps)
double roundedFrameTime = round(frameTime*10000) / 10000;
return (float)roundedFrameTime; // Time in seconds to run a frame
}
// Returns a Color struct from hexadecimal value
Color GetColor(int hexValue)
{
Color color;
color.r = (unsigned char)(hexValue >> 24) & 0xFF;
color.g = (unsigned char)(hexValue >> 16) & 0xFF;
color.b = (unsigned char)(hexValue >> 8) & 0xFF;
color.a = (unsigned char)hexValue & 0xFF;
return color;
}
// Returns hexadecimal value for a Color
int GetHexValue(Color color)
{
return ((color.a << 24) + (color.r << 16) + (color.g << 8) + color.b);
}
//----------------------------------------------------------------------------------
// Module Functions Definition - Input (Keyboard, Mouse, Gamepad) Functions
//----------------------------------------------------------------------------------
// Detect if a key is being pressed (key held down)
bool IsKeyPressed(int key)
{
if (glfwGetKey(window, key) == GLFW_PRESS) return true;
else return false;
}
// Detect if a key is NOT being pressed (key not held down)
bool IsKeyReleased(int key)
{
if (glfwGetKey(window, key) == GLFW_RELEASE) return true;
else return false;
}
// Detect if a mouse button is being pressed
bool IsMouseButtonPressed(int button)
{
if (glfwGetMouseButton(window, button) == GLFW_PRESS) return true;
else return false;
}
// Detect if a mouse button is NOT being pressed
bool IsMouseButtonReleased(int button)
{
if (glfwGetMouseButton(window, button) == GLFW_RELEASE) return true;
else return false;
}
// Returns mouse position X
int GetMouseX()
{
double mouseX;
double mouseY;
glfwGetCursorPos(window, &mouseX, &mouseY);
return (int)mouseX;
}
// Returns mouse position Y
int GetMouseY()
{
double mouseX;
double mouseY;
glfwGetCursorPos(window, &mouseX, &mouseY);
return (int)mouseY;
}
// Returns mouse position XY
Vector2 GetMousePosition()
{
double mouseX;
double mouseY;
glfwGetCursorPos(window, &mouseX, &mouseY);
Vector2 position = { (float)mouseX, (float)mouseY };
return position;
}
// Detect if a gamepad is available
bool IsGamepadAvailable(int gamepad)
{
int result = glfwJoystickPresent(gamepad);
if (result == 1) return true;
else return false;
}
// Return axis movement vector for a gamepad
Vector2 GetGamepadMovement(int gamepad)
{
Vector2 vec = { 0, 0 };
const float *axes;
int axisCount;
axes = glfwGetJoystickAxes(gamepad, &axisCount);
if (axisCount >= 2)
{
vec.x = axes[0]; // Left joystick X
vec.y = axes[1]; // Left joystick Y
//vec.x = axes[2]; // Right joystick X
//vec.x = axes[3]; // Right joystick Y
}
return vec;
}
// Detect if a gamepad button is being pressed
bool IsGamepadButtonPressed(int gamepad, int button)
{
const unsigned char* buttons;
int buttonsCount;
buttons = glfwGetJoystickButtons(gamepad, &buttonsCount);
if (buttons[button] == GLFW_PRESS)
{
return true;
}
else return false;
}
// Detect if a gamepad button is NOT being pressed
bool IsGamepadButtonReleased(int gamepad, int button)
{
const unsigned char* buttons;
int buttonsCount;
buttons = glfwGetJoystickButtons(gamepad, &buttonsCount);
if (buttons[button] == GLFW_RELEASE)
{
return true;
}
else return false;
}
//----------------------------------------------------------------------------------
// Module specific Functions Definition
//----------------------------------------------------------------------------------
// GLFW3 Error Callback, runs on GLFW3 error
static void ErrorCallback(int error, const char *description)
{
printf(description);
//fprintf(stderr, description);
}
// GLFW3 Keyboard Callback, runs on key pressed
static void KeyCallback(GLFWwindow* window, int key, int scancode, int action, int mods)
{
if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
{
glfwSetWindowShouldClose(window, GL_TRUE);
// NOTE: Before closing window, while loop must be left!
}
else if (key == GLFW_KEY_F11 && action == GLFW_PRESS)
{
ToggleFullscreen();
}
else if (key == GLFW_KEY_F12 && action == GLFW_PRESS)
{
TakeScreenshot();
}
}
// GLFW3 WindowSize Callback, runs when window is resized
static void WindowSizeCallback(GLFWwindow* window, int width, int height)
{
InitGraphicsDevice(); // If window is resized, graphics device is re-initialized
// NOTE: Aspect ratio does not change, so, image can be deformed
}
// Initialize Graphics Device (OpenGL stuff)
static void InitGraphicsDevice()
{
int fbWidth, fbHeight;
glfwGetFramebufferSize(window, &fbWidth, &fbHeight); // Get framebuffer size of current window
glViewport(0, 0, fbWidth, fbHeight); // Set viewport width and height
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear used buffers, depth buffer is used for 3D
glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // Set background color (black)
glClearDepth(1.0f); // Clear depth buffer
glEnable(GL_DEPTH_TEST); // Enables depth testing (required for 3D)
glDepthFunc(GL_LEQUAL); // Type of depth testing to apply
glEnable(GL_BLEND); // Enable color blending (required to work with transparencies)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); // Color blending function (how colors are mixed)
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); // Improve quality of color and texture coordinate interpolation (Deprecated in OGL 3.0)
// Other options: GL_FASTEST, GL_DONT_CARE (default)
glMatrixMode(GL_PROJECTION); // Switch to PROJECTION matrix
glLoadIdentity(); // Reset current matrix (PROJECTION)
glOrtho(0, fbWidth, fbHeight, 0, 0, 1); // Config orthographic mode: top-left corner --> (0,0)
glMatrixMode(GL_MODELVIEW); // Switch back to MODELVIEW matrix
glLoadIdentity(); // Reset current matrix (MODELVIEW)
glDisable(GL_LIGHTING); // Lighting Disabled...
// TODO: Create an efficient Lighting System with proper functions (raylib 1.x)
/*
glEnable(GL_COLOR_MATERIAL); // Enable materials, causes some glMaterial atributes to track the current color (glColor)...
glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE); // Material types and where to apply them
// NOTE: ONLY works with lighting; defines how light interacts with material
glLightfv(GL_LIGHT1, GL_AMBIENT, lightAmbient); // Define ambient light color property
glLightfv(GL_LIGHT1, GL_DIFFUSE, lightDiffuse); // Define diffuse light color property
glLightfv(GL_LIGHT1, GL_POSITION, lightPosition); // Define light position
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT1); // Enable light one (8 lights available at the same time)
*/
// TODO: Review all shapes/models are drawn CCW and enable backface culling
//glEnable(GL_CULL_FACE); // Enable backface culling (Disabled by default)
//glCullFace(GL_BACK); // Cull the Back face (default)
//glFrontFace(GL_CCW); // Front face are defined counter clockwise (default)
glShadeModel(GL_SMOOTH); // Smooth shading between vertex (vertex colors interpolation)
// Possible options: GL_SMOOTH (Color interpolation) or GL_FLAT (no interpolation)
}
// Setup camera view (updates MODELVIEW matrix)
static void CameraLookAt(Vector3 position, Vector3 target, Vector3 up)
{
float rotMatrix[16]; // Matrix to store camera rotation
Vector3 rotX, rotY, rotZ; // Vectors to calculate camera rotations X, Y, Z (Euler)
// Construct rotation matrix from vectors
rotZ = VectorSubtract(position, target);
VectorNormalize(&rotZ);
rotY = up; // Y rotation vector
rotX = VectorCrossProduct(rotY, rotZ); // X rotation vector = Y cross Z
rotY = VectorCrossProduct(rotZ, rotX); // Recompute Y rotation = Z cross X
VectorNormalize(&rotX); // X rotation vector normalization
VectorNormalize(&rotY); // Y rotation vector normalization
rotMatrix[0] = rotX.x;
rotMatrix[1] = rotY.x;
rotMatrix[2] = rotZ.x;
rotMatrix[3] = 0.0f;
rotMatrix[4] = rotX.y;
rotMatrix[5] = rotY.y;
rotMatrix[6] = rotZ.y;
rotMatrix[7] = 0.0f;
rotMatrix[8] = rotX.z;
rotMatrix[9] = rotY.z;
rotMatrix[10] = rotZ.z;
rotMatrix[11] = 0.0f;
rotMatrix[12] = 0.0f;
rotMatrix[13] = 0.0f;
rotMatrix[14] = 0.0f;
rotMatrix[15] = 1.0f;
glMultMatrixf(rotMatrix); // Multiply MODELVIEW matrix by rotation matrix
glTranslatef(-position.x, -position.y, -position.z); // Translate eye to position
}
// Setup view projection (updates PROJECTION matrix)
static void SetPerspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar)
{
double xmin, xmax, ymin, ymax;
ymax = zNear * tan(fovy * PI / 360.0);
ymin = -ymax;
xmin = ymin * aspect;
xmax = ymax * aspect;
glFrustum(xmin, xmax, ymin, ymax, zNear, zFar);
}
// Takes a bitmap (BMP) screenshot and saves it in the same folder as executable
static void TakeScreenshot()
{
static int shotNum = 0; // Screenshot number, increments every screenshot take during program execution
char buffer[20]; // Buffer to store file name
int fbWidth, fbHeight;
Color *imgDataPixel; // Pixel image data array
glfwGetFramebufferSize(window, &fbWidth, &fbHeight); // Get framebuffer size of current window
imgDataPixel = (Color *)malloc(fbWidth * fbHeight * sizeof(Color));
// NOTE: glReadPixels returns image flipped vertically -> (0,0) is the bottom left corner of the framebuffer
glReadPixels(0, 0, fbWidth, fbHeight, GL_RGBA, GL_UNSIGNED_BYTE, imgDataPixel);
sprintf(buffer, "screenshot%03i.bmp", shotNum);
// NOTE: BMP directly stores data flipped vertically
WriteBitmap(buffer, imgDataPixel, fbWidth, fbHeight); // Writes pixel data array into a bitmap (BMP) file
free(imgDataPixel);
shotNum++;
}