[rmodels] Implement DrawTexturePro3D

src/raylib.h

@@ -247,12 +247,29 @@ typedef struct Color {
 
 // Rectangle, 4 components
 typedef struct Rectangle {
-    float x;                // Rectangle top-left corner position x
-    float y;                // Rectangle top-left corner position y
-    float width;            // Rectangle width
-    float height;           // Rectangle height
+    union {
+        struct {
+            float x;        // Rectangle top-left corner position x
+            float y;        // Rectangle top-left corner position y
+        };
+        Vector2 position;
+    };
+    union {
+        struct {
+            float width;    // Rectangle width
+            float height;   // Rectangle height
+        };
+        Vector2 size;
+    };
 } Rectangle;
 
+// Rectangle3D, rectangle in 3D space
+typedef struct Rectangle3D {
+    Vector3 position;       // Origin of two sides (up and right) of the rectangle
+    Vector3 up;             // Length and direction of one side of the rectangle
+    Vector3 right;          // Length and direction of another side of the rectangle
+} Rectangle3D;
+
 // Image, pixel data stored in CPU memory (RAM)
 typedef struct Image {
     void *data;             // Image raw data
@@ -1546,6 +1563,7 @@ RLAPI void DrawModelEx(Model model, Vector3 position, Vector3 rotationAxis, floa
 RLAPI void DrawModelWires(Model model, Vector3 position, float scale, Color tint);          // Draw a model wires (with texture if set)
 RLAPI void DrawModelWiresEx(Model model, Vector3 position, Vector3 rotationAxis, float rotationAngle, Vector3 scale, Color tint); // Draw a model wires (with texture if set) with extended parameters
 RLAPI void DrawBoundingBox(BoundingBox box, Color color);                                   // Draw bounding box (wires)
+RLAPI void DrawTexturePro3D(Texture2D texture, Rectangle source, Rectangle3D dest, Vector2 origin, float rotation, Color tint);
 RLAPI void DrawBillboard(Camera camera, Texture2D texture, Vector3 position, float size, Color tint);   // Draw a billboard texture
 RLAPI void DrawBillboardRec(Camera camera, Texture2D texture, Rectangle source, Vector3 position, Vector2 size, Color tint); // Draw a billboard texture defined by source
 RLAPI void DrawBillboardPro(Camera camera, Texture2D texture, Rectangle source, Vector3 position, Vector3 up, Vector2 size, Vector2 origin, float rotation, Color tint); // Draw a billboard texture defined by source and rotation

src/rmodels.c

@@ -3654,6 +3654,46 @@ void DrawBillboardRec(Camera camera, Texture2D texture, Rectangle source, Vector
     DrawBillboardPro(camera, texture, source, position, up, size, Vector2Zero(), 0.0f, tint);
 }
 
+void DrawTexturePro3D(Texture2D texture, Rectangle source, Rectangle3D dest, Vector2 origin, float rotation, Color tint)
+{
+    Vector3 forward;
+    if (rotation != 0.0) forward =  Vector3CrossProduct(dest.right, dest.up);
+
+    Vector3 origin3D = Vector3Add(Vector3Scale(Vector3Normalize(dest.up), origin.y), Vector3Scale(Vector3Normalize(dest.right), origin.x));
+
+    Vector3 points[4];
+    points[0] = Vector3Zero();
+    points[1] = dest.right;
+    points[2] = Vector3Add(dest.up, dest.right);
+    points[3] = dest.up;
+
+    for (int i = 0; i < 4; i++)
+    {
+        points[i] = Vector3Subtract(points[i], origin3D);
+        if (rotation != 0.0) points[i] = Vector3RotateByAxisAngle(points[i], forward, rotation * DEG2RAD);
+        points[i] = Vector3Add(points[i], dest.position);
+    }
+
+    Vector2 texcoords[4];
+    texcoords[0] = (Vector2) { (float)source.x/texture.width, (float)(source.y + source.height)/texture.height };
+    texcoords[1] = (Vector2) { (float)(source.x + source.width)/texture.width, (float)(source.y + source.height)/texture.height };
+    texcoords[2] = (Vector2) { (float)(source.x + source.width)/texture.width, (float)source.y/texture.height };
+    texcoords[3] = (Vector2) { (float)source.x/texture.width, (float)source.y/texture.height };
+
+    rlSetTexture(texture.id);
+    rlBegin(RL_QUADS);
+
+        rlColor4ub(tint.r, tint.g, tint.b, tint.a);
+        for (int i = 0; i < 4; i++)
+        {
+            rlTexCoord2f(texcoords[i].x, texcoords[i].y);
+            rlVertex3f(points[i].x, points[i].y, points[i].z);
+        }
+
+    rlEnd();
+    rlSetTexture(0);
+}
+
 // Draw a billboard with additional parameters
 // NOTE: Size defines the destination rectangle size, stretching the source texture as required
 void DrawBillboardPro(Camera camera, Texture2D texture, Rectangle source, Vector3 position, Vector3 up, Vector2 size, Vector2 origin, float rotation, Color tint)