raylib/examples/others/rlgl_standalone.c
2021-03-23 11:51:09 +01:00

444 lines
19 KiB
C

/*******************************************************************************************
*
* raylib [rlgl] example - Using rlgl module as standalone module
*
* NOTE: This example requires OpenGL 3.3 or ES2 versions for shaders support,
* OpenGL 1.1 does not support shaders but it can also be used.
*
* DEPENDENCIES:
* rlgl.h - OpenGL 1.1 immediate-mode style coding translation layer
* glad.h - OpenGL extensions initialization library (required by rlgl)
* raymath.h - 3D math library (required by rlgl)
* glfw3 - Windows and context initialization library
*
* rlgl library is provided as a single-file header-only library, this library
* allows coding in a pseudo-OpenGL 1.1 style while translating calls to multiple
* OpenGL versions backends (1.1, 2.1, 3.3, ES 2.0).
*
* WINDOWS COMPILATION:
* gcc -o rlgl_standalone.exe rlgl_standalone.c -s -Iexternal\include -I..\..\src \
* -L. -Lexternal\lib -lglfw3 -lopengl32 -lgdi32 -Wall -std=c99 -DGRAPHICS_API_OPENGL_33
*
* APPLE COMPILATION:
* gcc -o rlgl_standalone rlgl_standalone.c -I../../src -Iexternal/include -Lexternal/lib \
* -lglfw3 -std=c99 -framework CoreVideo -framework OpenGL -framework OpenAL \
* -framework IOKit -framework Cocoa -Wno-deprecated-declarations
*
* LICENSE: zlib/libpng
*
* This example is licensed under an unmodified zlib/libpng license, which is an OSI-certified,
* BSD-like license that allows static linking with closed source software:
*
* Copyright (c) 2014-2019 Ramon Santamaria (@raysan5)
*
* 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.
*
********************************************************************************************/
#define RLGL_IMPLEMENTATION
#define RLGL_STANDALONE
#define RLGL_SUPPORT_TRACELOG
#include "rlgl.h" // OpenGL 1.1 immediate-mode style coding
#if defined(__EMSCRIPTEN__)
#define GLFW_INCLUDE_ES2
#endif
#include "GLFW/glfw3.h" // Windows/Context and inputs management
#include <stdio.h> // Required for: printf()
#define RED (Color){ 230, 41, 55, 255 } // Red
#define RAYWHITE (Color){ 245, 245, 245, 255 } // My own White (raylib logo)
#define DARKGRAY (Color){ 80, 80, 80, 255 } // Dark Gray
// Camera type, defines a camera position/orientation in 3d space
typedef struct Camera {
Vector3 position; // Camera position
Vector3 target; // Camera target it looks-at
Vector3 up; // Camera up vector (rotation over its axis)
float fovy; // Camera field-of-view apperture in Y (degrees) in perspective, used as near plane width in orthographic
int projection; // Camera projection: CAMERA_PERSPECTIVE or CAMERA_ORTHOGRAPHIC
} Camera;
//----------------------------------------------------------------------------------
// Module specific Functions Declaration
//----------------------------------------------------------------------------------
static void ErrorCallback(int error, const char *description);
static void KeyCallback(GLFWwindow *window, int key, int scancode, int action, int mods);
// Drawing functions (uses rlgl functionality)
static void DrawGrid(int slices, float spacing);
static void DrawCube(Vector3 position, float width, float height, float length, Color color);
static void DrawCubeWires(Vector3 position, float width, float height, float length, Color color);
static void DrawRectangleV(Vector2 position, Vector2 size, Color color);
//----------------------------------------------------------------------------------
// Main Entry point
//----------------------------------------------------------------------------------
int main(void)
{
// Initialization
//--------------------------------------------------------------------------------------
const int screenWidth = 800;
const int screenHeight = 450;
// GLFW3 Initialization + OpenGL 3.3 Context + Extensions
//--------------------------------------------------------
glfwSetErrorCallback(ErrorCallback);
if (!glfwInit())
{
printf("GLFW3: Can not initialize GLFW\n");
return 1;
}
else printf("GLFW3: GLFW initialized successfully\n");
glfwWindowHint(GLFW_SAMPLES, 4);
glfwWindowHint(GLFW_DEPTH_BITS, 16);
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
//glfwWindowHint(GLFW_OPENGL_DEBUG_CONTEXT, GL_TRUE);
#if defined(__APPLE__)
glfwWindowHint( GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE );
#endif
GLFWwindow *window = glfwCreateWindow(screenWidth, screenHeight, "rlgl standalone", NULL, NULL);
if (!window)
{
glfwTerminate();
return 2;
}
else printf("GLFW3: Window created successfully\n");
glfwSetWindowPos(window, 200, 200);
glfwSetKeyCallback(window, KeyCallback);
glfwMakeContextCurrent(window);
glfwSwapInterval(0);
// Load OpenGL 3.3 supported extensions
rlLoadExtensions(glfwGetProcAddress);
//--------------------------------------------------------
// Initialize OpenGL context (states and resources)
rlglInit(screenWidth, screenHeight);
// Initialize viewport and internal projection/modelview matrices
rlViewport(0, 0, screenWidth, screenHeight);
rlMatrixMode(RL_PROJECTION); // Switch to PROJECTION matrix
rlLoadIdentity(); // Reset current matrix (PROJECTION)
rlOrtho(0, screenWidth, screenHeight, 0, 0.0f, 1.0f); // Orthographic projection with top-left corner at (0,0)
rlMatrixMode(RL_MODELVIEW); // Switch back to MODELVIEW matrix
rlLoadIdentity(); // Reset current matrix (MODELVIEW)
rlClearColor(245, 245, 245, 255); // Define clear color
rlEnableDepthTest(); // Enable DEPTH_TEST for 3D
Camera camera = { 0 };
camera.position = (Vector3){ 5.0f, 5.0f, 5.0f }; // Camera position
camera.target = (Vector3){ 0.0f, 0.0f, 0.0f }; // Camera looking at point
camera.up = (Vector3){ 0.0f, 1.0f, 0.0f }; // Camera up vector (rotation towards target)
camera.fovy = 45.0f; // Camera field-of-view Y
Vector3 cubePosition = { 0.0f, 0.0f, 0.0f }; // Cube default position (center)
//--------------------------------------------------------------------------------------
// Main game loop
while (!glfwWindowShouldClose(window))
{
// Update
//----------------------------------------------------------------------------------
//camera.position.x += 0.01f;
//----------------------------------------------------------------------------------
// Draw
//----------------------------------------------------------------------------------
rlClearScreenBuffers(); // Clear current framebuffer
// Draw '3D' elements in the scene
//-----------------------------------------------
// Calculate projection matrix (from perspective) and view matrix from camera look at
Matrix matProj = MatrixPerspective(camera.fovy*DEG2RAD, (double)screenWidth/(double)screenHeight, 0.01, 1000.0);
Matrix matView = MatrixLookAt(camera.position, camera.target, camera.up);
rlSetMatrixModelview(matView); // Set internal modelview matrix (default shader)
rlSetMatrixProjection(matProj); // Set internal projection matrix (default shader)
DrawCube(cubePosition, 2.0f, 2.0f, 2.0f, RED);
DrawCubeWires(cubePosition, 2.0f, 2.0f, 2.0f, RAYWHITE);
DrawGrid(10, 1.0f);
// Draw internal render batch buffers (3D data)
rlDrawRenderBatchActive();
//-----------------------------------------------
// Draw '2D' elements in the scene (GUI)
//-----------------------------------------------
#define RLGL_CREATE_MATRIX_MANUALLY
#if defined(RLGL_CREATE_MATRIX_MANUALLY)
matProj = MatrixOrtho(0.0, screenWidth, screenHeight, 0.0, 0.0, 1.0);
matView = MatrixIdentity();
rlSetMatrixModelview(matView); // Set internal modelview matrix (default shader)
rlSetMatrixProjection(matProj); // Set internal projection matrix (default shader)
#else // Let rlgl generate and multiply matrix internally
rlMatrixMode(RL_PROJECTION); // Enable internal projection matrix
rlLoadIdentity(); // Reset internal projection matrix
rlOrtho(0.0, screenWidth, screenHeight, 0.0, 0.0, 1.0); // Recalculate internal projection matrix
rlMatrixMode(RL_MODELVIEW); // Enable internal modelview matrix
rlLoadIdentity(); // Reset internal modelview matrix
#endif
DrawRectangleV((Vector2){ 10.0f, 10.0f }, (Vector2){ 780.0f, 20.0f }, DARKGRAY);
// Draw internal render batch buffers (3D data)
rlDrawRenderBatchActive();
//-----------------------------------------------
glfwSwapBuffers(window);
glfwPollEvents();
//----------------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
rlglClose(); // Unload rlgl internal buffers and default shader/texture
glfwDestroyWindow(window); // Close window
glfwTerminate(); // Free GLFW3 resources
//--------------------------------------------------------------------------------------
return 0;
}
//----------------------------------------------------------------------------------
// Module specific Functions Definitions
//----------------------------------------------------------------------------------
// GLFW3: Error callback
static void ErrorCallback(int error, const char *description)
{
fprintf(stderr, "%s", description);
}
// GLFW3: Keyboard callback
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);
}
}
// Draw rectangle using rlgl OpenGL 1.1 style coding (translated to OpenGL 3.3 internally)
static void DrawRectangleV(Vector2 position, Vector2 size, Color color)
{
rlBegin(RL_TRIANGLES);
rlColor4ub(color.r, color.g, color.b, color.a);
rlVertex2f(position.x, position.y);
rlVertex2f(position.x, position.y + size.y);
rlVertex2f(position.x + size.x, position.y + size.y);
rlVertex2f(position.x, position.y);
rlVertex2f(position.x + size.x, position.y + size.y);
rlVertex2f(position.x + size.x, position.y);
rlEnd();
}
// Draw a grid centered at (0, 0, 0)
static void DrawGrid(int slices, float spacing)
{
int halfSlices = slices / 2;
rlBegin(RL_LINES);
for(int i = -halfSlices; i <= halfSlices; i++)
{
if (i == 0)
{
rlColor3f(0.5f, 0.5f, 0.5f);
rlColor3f(0.5f, 0.5f, 0.5f);
rlColor3f(0.5f, 0.5f, 0.5f);
rlColor3f(0.5f, 0.5f, 0.5f);
}
else
{
rlColor3f(0.75f, 0.75f, 0.75f);
rlColor3f(0.75f, 0.75f, 0.75f);
rlColor3f(0.75f, 0.75f, 0.75f);
rlColor3f(0.75f, 0.75f, 0.75f);
}
rlVertex3f((float)i*spacing, 0.0f, (float)-halfSlices*spacing);
rlVertex3f((float)i*spacing, 0.0f, (float)halfSlices*spacing);
rlVertex3f((float)-halfSlices*spacing, 0.0f, (float)i*spacing);
rlVertex3f((float)halfSlices*spacing, 0.0f, (float)i*spacing);
}
rlEnd();
}
// Draw cube
// NOTE: Cube position is the center position
static void DrawCube(Vector3 position, float width, float height, float length, Color color)
{
float x = 0.0f;
float y = 0.0f;
float z = 0.0f;
rlPushMatrix();
// NOTE: Be careful! Function order matters (rotate -> scale -> translate)
rlTranslatef(position.x, position.y, position.z);
//rlScalef(2.0f, 2.0f, 2.0f);
//rlRotatef(45, 0, 1, 0);
rlBegin(RL_TRIANGLES);
rlColor4ub(color.r, color.g, color.b, color.a);
// Front Face -----------------------------------------------------
rlVertex3f(x-width/2, y-height/2, z+length/2); // Bottom Left
rlVertex3f(x+width/2, y-height/2, z+length/2); // Bottom Right
rlVertex3f(x-width/2, y+height/2, z+length/2); // Top Left
rlVertex3f(x+width/2, y+height/2, z+length/2); // Top Right
rlVertex3f(x-width/2, y+height/2, z+length/2); // Top Left
rlVertex3f(x+width/2, y-height/2, z+length/2); // Bottom Right
// Back Face ------------------------------------------------------
rlVertex3f(x-width/2, y-height/2, z-length/2); // Bottom Left
rlVertex3f(x-width/2, y+height/2, z-length/2); // Top Left
rlVertex3f(x+width/2, y-height/2, z-length/2); // Bottom Right
rlVertex3f(x+width/2, y+height/2, z-length/2); // Top Right
rlVertex3f(x+width/2, y-height/2, z-length/2); // Bottom Right
rlVertex3f(x-width/2, y+height/2, z-length/2); // Top Left
// Top Face -------------------------------------------------------
rlVertex3f(x-width/2, y+height/2, z-length/2); // Top Left
rlVertex3f(x-width/2, y+height/2, z+length/2); // Bottom Left
rlVertex3f(x+width/2, y+height/2, z+length/2); // Bottom Right
rlVertex3f(x+width/2, y+height/2, z-length/2); // Top Right
rlVertex3f(x-width/2, y+height/2, z-length/2); // Top Left
rlVertex3f(x+width/2, y+height/2, z+length/2); // Bottom Right
// Bottom Face ----------------------------------------------------
rlVertex3f(x-width/2, y-height/2, z-length/2); // Top Left
rlVertex3f(x+width/2, y-height/2, z+length/2); // Bottom Right
rlVertex3f(x-width/2, y-height/2, z+length/2); // Bottom Left
rlVertex3f(x+width/2, y-height/2, z-length/2); // Top Right
rlVertex3f(x+width/2, y-height/2, z+length/2); // Bottom Right
rlVertex3f(x-width/2, y-height/2, z-length/2); // Top Left
// Right face -----------------------------------------------------
rlVertex3f(x+width/2, y-height/2, z-length/2); // Bottom Right
rlVertex3f(x+width/2, y+height/2, z-length/2); // Top Right
rlVertex3f(x+width/2, y+height/2, z+length/2); // Top Left
rlVertex3f(x+width/2, y-height/2, z+length/2); // Bottom Left
rlVertex3f(x+width/2, y-height/2, z-length/2); // Bottom Right
rlVertex3f(x+width/2, y+height/2, z+length/2); // Top Left
// Left Face ------------------------------------------------------
rlVertex3f(x-width/2, y-height/2, z-length/2); // Bottom Right
rlVertex3f(x-width/2, y+height/2, z+length/2); // Top Left
rlVertex3f(x-width/2, y+height/2, z-length/2); // Top Right
rlVertex3f(x-width/2, y-height/2, z+length/2); // Bottom Left
rlVertex3f(x-width/2, y+height/2, z+length/2); // Top Left
rlVertex3f(x-width/2, y-height/2, z-length/2); // Bottom Right
rlEnd();
rlPopMatrix();
}
// Draw cube wires
static void DrawCubeWires(Vector3 position, float width, float height, float length, Color color)
{
float x = 0.0f;
float y = 0.0f;
float z = 0.0f;
rlPushMatrix();
rlTranslatef(position.x, position.y, position.z);
//rlRotatef(45, 0, 1, 0);
rlBegin(RL_LINES);
rlColor4ub(color.r, color.g, color.b, color.a);
// Front Face -----------------------------------------------------
// Bottom Line
rlVertex3f(x-width/2, y-height/2, z+length/2); // Bottom Left
rlVertex3f(x+width/2, y-height/2, z+length/2); // Bottom Right
// Left Line
rlVertex3f(x+width/2, y-height/2, z+length/2); // Bottom Right
rlVertex3f(x+width/2, y+height/2, z+length/2); // Top Right
// Top Line
rlVertex3f(x+width/2, y+height/2, z+length/2); // Top Right
rlVertex3f(x-width/2, y+height/2, z+length/2); // Top Left
// Right Line
rlVertex3f(x-width/2, y+height/2, z+length/2); // Top Left
rlVertex3f(x-width/2, y-height/2, z+length/2); // Bottom Left
// Back Face ------------------------------------------------------
// Bottom Line
rlVertex3f(x-width/2, y-height/2, z-length/2); // Bottom Left
rlVertex3f(x+width/2, y-height/2, z-length/2); // Bottom Right
// Left Line
rlVertex3f(x+width/2, y-height/2, z-length/2); // Bottom Right
rlVertex3f(x+width/2, y+height/2, z-length/2); // Top Right
// Top Line
rlVertex3f(x+width/2, y+height/2, z-length/2); // Top Right
rlVertex3f(x-width/2, y+height/2, z-length/2); // Top Left
// Right Line
rlVertex3f(x-width/2, y+height/2, z-length/2); // Top Left
rlVertex3f(x-width/2, y-height/2, z-length/2); // Bottom Left
// Top Face -------------------------------------------------------
// Left Line
rlVertex3f(x-width/2, y+height/2, z+length/2); // Top Left Front
rlVertex3f(x-width/2, y+height/2, z-length/2); // Top Left Back
// Right Line
rlVertex3f(x+width/2, y+height/2, z+length/2); // Top Right Front
rlVertex3f(x+width/2, y+height/2, z-length/2); // Top Right Back
// Bottom Face ---------------------------------------------------
// Left Line
rlVertex3f(x-width/2, y-height/2, z+length/2); // Top Left Front
rlVertex3f(x-width/2, y-height/2, z-length/2); // Top Left Back
// Right Line
rlVertex3f(x+width/2, y-height/2, z+length/2); // Top Right Front
rlVertex3f(x+width/2, y-height/2, z-length/2); // Top Right Back
rlEnd();
rlPopMatrix();
}