Merge pull request #513 from autious/master

Add orthographic 3d rendering mode

3 files changed, 183 insertions, 11 deletions

diff --git a/examples/models/models_orthographic_projection.c b/examples/models/models_orthographic_projection.c
new file mode 100644
index 00000000..2c2a89d1
--- /dev/null
+++ b/examples/models/models_orthographic_projection.c
@@ -0,0 +1,112 @@
+/*******************************************************************************************
+*
+*   raylib [models] example - Show the difference between perspective and orthographic projection 
+*
+*   This program is heavily based on the geometric objects example
+*
+*   This example has been created using raylib 1.0 (www.raylib.com)
+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
+*
+*   Copyright (c) 2014 Ramon Santamaria (@raysan5)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+
+#define FOVY_PERSPECTIVE 45.0f
+#define WIDTH_ORTHOGRAPHIC 10.0f
+
+int main()
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    int screenWidth = 800;
+    int screenHeight = 450;
+
+    InitWindow(screenWidth, screenHeight, "raylib [models] example - geometric shapes");
+
+    // Define the camera to look into our 3d world
+    Camera camera = {{ 0.0f, 10.0f, 10.0f }, { 0.0f, 0.0f, 0.0f }, { 0.0f, 1.0f, 0.0f }, FOVY_PERSPECTIVE, CAMERA_PERSPECTIVE };
+
+    SetTargetFPS(60);   // Set our game to run at 60 frames-per-second
+    //--------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        // TODO: Update your variables here
+        //----------------------------------------------------------------------------------
+        //
+
+        // Input
+        //----------------------------------------------------------------------------------
+        if(IsKeyPressed(KEY_SPACE)) 
+        {
+            if(camera.type == CAMERA_PERSPECTIVE) 
+            {
+                camera.fovy = WIDTH_ORTHOGRAPHIC;
+                camera.type = CAMERA_ORTHOGRAPHIC;
+            } 
+            else 
+            {
+                camera.fovy = FOVY_PERSPECTIVE;
+                camera.type = CAMERA_PERSPECTIVE;
+            }
+        }
+
+
+        // Draw
+        //----------------------------------------------------------------------------------
+
+
+        BeginDrawing();
+
+            ClearBackground(RAYWHITE);
+
+            Begin3dMode(camera);
+
+                DrawCube((Vector3){-4.0f, 0.0f, 2.0f}, 2.0f, 5.0f, 2.0f, RED);
+                DrawCubeWires((Vector3){-4.0f, 0.0f, 2.0f}, 2.0f, 5.0f, 2.0f, GOLD);
+                DrawCubeWires((Vector3){-4.0f, 0.0f, -2.0f}, 3.0f, 6.0f, 2.0f, MAROON);
+
+                DrawSphere((Vector3){-1.0f, 0.0f, -2.0f}, 1.0f, GREEN);
+                DrawSphereWires((Vector3){1.0f, 0.0f, 2.0f}, 2.0f, 16, 16, LIME);
+
+                DrawCylinder((Vector3){4.0f, 0.0f, -2.0f}, 1.0f, 2.0f, 3.0f, 4, SKYBLUE);
+                DrawCylinderWires((Vector3){4.0f, 0.0f, -2.0f}, 1.0f, 2.0f, 3.0f, 4, DARKBLUE);
+                DrawCylinderWires((Vector3){4.5f, -1.0f, 2.0f}, 1.0f, 1.0f, 2.0f, 6, BROWN);
+
+                DrawCylinder((Vector3){1.0f, 0.0f, -4.0f}, 0.0f, 1.5f, 3.0f, 8, GOLD);
+                DrawCylinderWires((Vector3){1.0f, 0.0f, -4.0f}, 0.0f, 1.5f, 3.0f, 8, PINK);
+
+                DrawGrid(10, 1.0f);        // Draw a grid
+
+            End3dMode();
+
+            DrawFPS(10, 10);
+
+            DrawText("Press Spacebar to switch camera type", 10, 40, 24, BLACK);
+
+            if(camera.type == CAMERA_ORTHOGRAPHIC)
+            {
+                DrawText("Orthographic", 10, 65, 24, BLACK);
+            }
+            else if(camera.type == CAMERA_PERSPECTIVE)
+            {
+                DrawText("Perspective", 10, 65, 24, BLACK);
+            }
+
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+    CloseWindow();        // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}
diff --git a/src/core.c b/src/core.c
index 89a6f924..99cc3c5a 100644
--- a/src/core.c
+++ b/src/core.c
@@ -919,13 +919,26 @@ void Begin3dMode(Camera camera)
     rlPushMatrix();                     // Save previous matrix, which contains the settings for the 2d ortho projection
     rlLoadIdentity();                   // Reset current matrix (PROJECTION)
 
-    // Setup perspective projection
     float aspect = (float)screenWidth/(float)screenHeight;
-    double top = 0.01*tan(camera.fovy*0.5*DEG2RAD);
-    double right = top*aspect;
+
+    if(camera.type == CAMERA_PERSPECTIVE) 
+    {
+        // Setup perspective projection
+        double top = 0.01*tan(camera.fovy*0.5*DEG2RAD);
+        double right = top*aspect;
+
+        rlFrustum(-right, right, -top, top, 0.01, 1000.0);
+    }
+    else if(camera.type == CAMERA_ORTHOGRAPHIC)
+    {
+        // Setup orthographic projection
+        double top = camera.fovy/2.0;
+        double right = top*aspect;
+
+        rlOrtho(-right,right,-top,top, 0.01, 1000.0);
+    }
 
     // NOTE: zNear and zFar values are important when computing depth buffer values
-    rlFrustum(-right, right, -top, top, 0.01, 1000.0);
 
     rlMatrixMode(RL_MODELVIEW);         // Switch back to modelview matrix
     rlLoadIdentity();                   // Reset current matrix (MODELVIEW)
@@ -1013,22 +1026,48 @@ Ray GetMouseRay(Vector2 mousePosition, Camera camera)
 
     TraceLog(LOG_DEBUG, "Device coordinates: (%f, %f, %f)", deviceCoords.x, deviceCoords.y, deviceCoords.z);
 
-    // Calculate projection matrix from perspective
-    Matrix matProj = MatrixPerspective(camera.fovy*DEG2RAD, ((double)GetScreenWidth()/(double)GetScreenHeight()), 0.01, 1000.0);
-
     // Calculate view matrix from camera look at
     Matrix matView = MatrixLookAt(camera.position, camera.target, camera.up);
 
+    Matrix matProj;
+
+    if(camera.type == CAMERA_PERSPECTIVE) 
+    {
+        // Calculate projection matrix from perspective
+        matProj = MatrixPerspective(camera.fovy*DEG2RAD, ((double)GetScreenWidth()/(double)GetScreenHeight()), 0.01, 1000.0);
+    }
+    else if(camera.type == CAMERA_ORTHOGRAPHIC)
+    {
+        float aspect = (float)screenWidth/(float)screenHeight;
+        double top = camera.fovy/2.0;
+        double right = top*aspect;
+        // Calculate projection matrix from orthographic
+        matProj = MatrixOrtho(-right, right, -top, top, 0.01, 1000.0);
+    }
+
     // Unproject far/near points
     Vector3 nearPoint = rlUnproject((Vector3){ deviceCoords.x, deviceCoords.y, 0.0f }, matProj, matView);
     Vector3 farPoint = rlUnproject((Vector3){ deviceCoords.x, deviceCoords.y, 1.0f }, matProj, matView);
 
+    // Unproject the mouse cursor in the near plane.
+    // We need this as the source position because orthographic projects, compared to perspect doesn't have a 
+    // convergence point, meaning that the "eye" of the camera is more like a plane than a point.
+    Vector3 cameraPlanePointerPos = rlUnproject((Vector3){ deviceCoords.x, deviceCoords.y, -1.0f }, matProj, matView);
+
     // Calculate normalized direction vector
     Vector3 direction = Vector3Subtract(farPoint, nearPoint);
     direction = Vector3Normalize(direction);
 
+    if(camera.type == CAMERA_PERSPECTIVE)
+    {
+        ray.position = camera.position;
+    }
+    else if(camera.type == CAMERA_ORTHOGRAPHIC) 
+    {
+        ray.position = cameraPlanePointerPos;
+    }
+
     // Apply calculated vectors to ray
-    ray.position = camera.position;
     ray.direction = direction;
 
     return ray;
@@ -1038,7 +1077,21 @@ Ray GetMouseRay(Vector2 mousePosition, Camera camera)
 Vector2 GetWorldToScreen(Vector3 position, Camera camera)
 {
     // Calculate projection matrix (from perspective instead of frustum
-    Matrix matProj = MatrixPerspective(camera.fovy*DEG2RAD, (double)GetScreenWidth()/(double)GetScreenHeight(), 0.01, 1000.0);
+    Matrix matProj;
+
+    if(camera.type == CAMERA_PERSPECTIVE) 
+    {
+        // Calculate projection matrix from perspective
+        matProj = MatrixPerspective(camera.fovy*DEG2RAD, ((double)GetScreenWidth()/(double)GetScreenHeight()), 0.01, 1000.0);
+    }
+    else if(camera.type == CAMERA_ORTHOGRAPHIC)
+    {
+        float aspect = (float)screenWidth/(float)screenHeight;
+        double top = camera.fovy/2.0;
+        double right = top*aspect;
+        // Calculate projection matrix from orthographic
+        matProj = MatrixOrtho(-right, right, -top, top, 0.01, 1000.0);
+    }
 
     // Calculate view matrix from camera look at (and transpose it)
     Matrix matView = MatrixLookAt(camera.position, camera.target, camera.up);
diff --git a/src/raylib.h b/src/raylib.h
index c94f4477..f40124e9 100644
--- a/src/raylib.h
+++ b/src/raylib.h
@@ -398,12 +398,19 @@ typedef struct SpriteFont {
     CharInfo *chars;        // Characters info data
 } SpriteFont;
 
+// Camera projection modes
+typedef enum {
+    CAMERA_PERSPECTIVE = 0,
+    CAMERA_ORTHOGRAPHIC
+} CameraType;
+
 // 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)
+    float fovy;             // Camera field-of-view apperture in Y (degrees) in perspective, used as near plane width in orthographic
+    CameraType type;        // Camera type, controlling projection type, either CAMERA_PERSPECTIVE or CAMERA_ORTHOGRAPHIC.
 } Camera;
 
 // Camera2D type, defines a 2d camera
@@ -726,7 +733,7 @@ RLAPI void BeginTextureMode(RenderTexture2D target);              // Initializes
 RLAPI void EndTextureMode(void);                                  // Ends drawing to render texture
 
 // Screen-space-related functions
-RLAPI Ray GetMouseRay(Vector2 mousePosition, Camera camera);      // Returns a ray trace from mouse position
+RLAPI Ray GetMouseRay(Vector2 mousePosition, Camera camera);            // Returns a ray trace from mouse position
 RLAPI Vector2 GetWorldToScreen(Vector3 position, Camera camera);  // Returns the screen space position for a 3d world space position
 RLAPI Matrix GetCameraMatrix(Camera camera);                      // Returns camera transform matrix (view matrix)